I also made unboxing video. :)
First time to upload a video on youtube.
EEVblog Multimeter Unboxing, Continuity Voltage review
https://youtu.be/tqFaSVsl-R4
It is CSV formatted and as the site doesn't allow that format ....
Dropped onto David's Droid software app while the meter was logging Temperature to the card. Hooked up fine and displayed the data in graph form and mirrored the display :-+
Hit the save button and it allowed me to save the raw captured data from the start of the sync period till then. Would be nice to have maybe a screen capture option as well.
Raw data captured via bluetooth below. Full log to follow off the SD card which is about 1500 records at 10 seconds.
The Time Stamp I haven't tried to figure out? Perhaps David might chime in?
time (s), Temp (°C)
1.734916, 36
3.002225, 36
5.636383, 36
8.999986, 35.9
9.731009, 36
10.41355, 36
10.6082, 35.9
12.41178, 35.8
13.72841, 35.8
14.41105, 36
I thought about buying one, because I really like the low burden voltage, logging, and bluetooth connectivity. But this thread (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/) suggests that it might be better to wait for the next revision, especially the reported contact problems of the rotary switch worries me. Can someone confirm this? The other problems, like unusable 7 seconds for ohms autorange, hopefully can be fixed by firmware updates.
Without knowing the actual code used for the autoranging I would suspect bloated and lazy code may be part of the issue. It is also possible looking at the bar graph that it is running a loop more than necessary to set a range. I think Dave needs a bit of time to get back from his break and do some to and fro with UEI and nothing really can be gained until that happens.
Decent speed on Auto-ranging is such a basic function that you’d think Dave made sure of this during the early stages developing the 121GW.
At the moment it's not an advanced meter but a well built prototype with basic features and hardware working.
If you want something working, you never buy the first revision.
Dropping the card out is a bit of a PITA.
You commented on the hassle of getting the SD card out from the meter to have access to the csv file for processing. Maybe Seppy, (Dave 2) can comment, but cant you have access to the csv file from the BLE app? I'm assuming the app on android can use dropbox, etc, or maybe the app is also available for your PC?
I would like to know if this is possible with the app?
Dropping the card out is a bit of a PITA.
It takes me 18 seconds to remove the boot, undo the screws, take off the cover remove the SD card and insert into the PC.
It takes often longer to dick around with a Bluetooth connection.
Dropping the card out is a bit of a PITA.
It takes me 18 seconds to remove the boot, undo the screws, take off the cover remove the SD card and insert into the PC.
It takes often longer to dick around with a Bluetooth connection.
That is very true, Bluetooth can also be a big PITA. 8)
As soon as there is PC support, I'll probably use that instead anyway.
Skip to 16:30 - Dave comments on the auto-ranging speed - infinity to zero ohms, for reference i measured it to 1.6 sec.
Skip to 16:30 - Dave comments on the auto-ranging speed - infinity to zero ohms, for reference i measured it to 1.6 sec.
Dave was 8 years younger in this video. When you get older, you are not that impatient anymore ;D
To me it’s totally unbelievably Dave would use high quality components - like a good reference and a modern MCU - and then severely limit the 121GW’s practical usability with a ridiculously - possibly even dangerously - slow auto-range speed.
It's not like someone would have said, "let's make it slow", and then did it deliberately. One day you have to ship product. You can't hold back forever, fixing every last detail before letting something out the door. If you do that you won't be in business.
To me it’s totally unbelievably Dave would use high quality components - like a good reference and a modern MCU - and then severely limit the 121GW’s practical usability with a ridiculously - possibly even dangerously - slow auto-range speed.
It's not like someone would have said, "let's make it slow", and then did it deliberately.
This DMM been 2 years under development and I just can't understand how on earth a basic thing like this issue was missed - or supposed to be good enough - you use auto-ranging most of the time you use a DMM - if it has that feature.
This DMM been 2 years under development and I just can't understand how on earth a basic thing like this issue was missed - or supposed to be good enough - you use auto-ranging most of the time you use a DMM - if it has that feature.
Sometimes the reality of working with a distant development team is that you cannot always get what you want out of them. For instance, if they don't know how to make auto-ranging faster, you might ask them again and again to make it faster, and it will be to no avail. If they don't know how to do it, they don't know how to do it. And if you don't own the team, what can you do about that?
I'm not saying this is what happened here, but this is the real world of product development, and things like this do happen. Just read all the complaints from Simon about the sub-contractors he works with...
This DMM been 2 years under
....
I'm not saying this is what happened here, but this is the real world of product development, and things like this do happen. Just read all the complaints from Simon about the sub-contractors he works with...
I think re-posting them would add little value at this point.
When Dave gets back he can address this the way he feels appropriate. Can the 121GW be speeded up?
what auto-range speed would the current HW allow?
So you basically just want to know if anything has changed. This makes sense. I setup a very simple test where I placed both the preproduction 121GW and Gossen M248B next to one another with a stop watch. I then drove the two meters using a common source between there min and max ranges. So both meters are triggered at the same time for all practical purposes.I think re-posting them would add little value at this point.
The only value I can see in those prototype videos would be if they somehow showed (significantly) faster auto-ranging than what's now been determined in the production model.
https://youtu.be/Gj9GrW2hi1c
When Dave gets back he can address this the way he feels appropriate. Can the 121GW be speeded up?
Almost certainly.
It is being worked on as the first priority, but do not ask for an update, I do not have one.Quotewhat auto-range speed would the current HW allow?
That's a much harder question to answer. Look at the Keysight 1282A perhaps, that uses the exact same front end chipset.
I think people are ignoring what is perhaps the most important question about this meter: can it handle a 1.21GW burst of electricity? ;DMaybe someone will send one to photonicinduction to put across his large cap. :-DD
Sadly, nobody has performed such a test, perhaps because it's difficult to put together. Even Joe might not be able to do that. Sounds like it might be a good opportunity for him to expand his pulse test equipment lineup. :-DD
We're rooting for you, Joe!
Thanks for showing this!
And here’s the major WTF moment - infinity to zero ohms - the Gossen is 4.1 sec just like I measured before - but the prototype 121GW is 3.8 sec!! compared to 7.4 sec on the production model I measured in Robert Culver's video - who showed how slow it was compared to his U1253 - a DMM Dave had ridiculed for being slow long time ago.
I wouldn't be surprised if joe got a cleaner more consistent contact is his test and possibly Robert Culver (unknowingly) had a bad probe or lead.
Also much of the ‘commotion’ with this issue being people’s different perspective of a fast/slow DMM - and not really prepared for what to expect with the 121GW - which was why I started to measure the time as accurate as possible in the video clips.
The U1282A was 3.5 and about 3.0 sec in 9fps mode - still kinda slooowish but more acceptable and hopefully 121GW can beat that.
I think people are ignoring what is perhaps the most important question about this meter: can it handle a 1.21GW burst of electricity? ;DSince that is enough to power 1,000,000 homes it might require a shunt.
I have done a rough-as-guts comparison of my handheld DMM collection ....
The bargraph on Joe’s prototype 121GW did not seem to flicker at all.
No but in that last attempt you can clearly see the fade in vs the half and half, or should I say half + 1 segment. :-DD
I could run a side by side of the meters that have survived all my abuse along with the counter to time it. Seems like an easier way to measure them anyway. My old analog meter settles pretty fast but does not have auto ranging. :-DD
Just to clarify - in my previous post I meant the two times Robert Culver tested his 121GW I saw the bargraph flicker in more or less the same place - as if the connection between his probes was intermittent. Compared to your prototype where the bargraph did not seem to flicker at all. Possibly this could be the indication of a bug the auto-ranging routine in Robet’s 121GW that causes bargraph flicker and overall slow auto-ranging speed.
Seems either the meter and or the reference has drifted 2 LSD. Decided not to try and figure out which as Yep that is 42+ degrees C on the bench :phew:
Has anyone in the USA received theirs?
Just to clarify you are relying on the videos of others for the content of your last 25 posts to search for any perceived (by you) flaws in a product you haven't used in the flesh? :palm:
Just to clarify you are relying on the videos of others for the content of your last 25 posts to search for any perceived (by you) flaws in a product you haven't used in the flesh? :palm:
Interesting comment on a Video blog related forum. For me videos are very useful to evaluate a product’s performance or apparent flaws, sorry if you can’t do that, please feel free to ignore my posts.
Asked that on the kickstarter page and received this from Dave on January 15th:Any word on publishing the format of the cal data and firmware files - these would be prerequisites for alternative firmware - probably possible to reverse-engineer, though it would be a bit of a pain.
They are being neatened up by UEI soon to be released, it will be posted in an update.
BTW is a full end-user recalibration possible ( this would make reversing the cal data easier if nothing else)?
BTW is a full end-user recalibration possible ( this would make reversing the cal data easier if nothing else)?
Seems to be, have a look at page 58 in the manual:
http://www.eevblog.com/files/EEVblog-121GW-Manual.pdf (http://www.eevblog.com/files/EEVblog-121GW-Manual.pdf)
4. Hold your breath, cross your fingers, and don't make any suddenWhat, no tongue angle specification ?
movements that could frighten the meter. Beard stroking is allowed.
Any word on publishing the format of the cal data and firmware files - these would be prerequisites for alternative firmware - probably possible to reverse-engineer, though it would be a bit of a pain.
BTW is a full end-user recalibration possible ( this would make reversing the cal data easier if nothing else)?
Maybe start a new hacking thread?Any word on publishing the format of the cal data and firmware files - these would be prerequisites for alternative firmware - probably possible to reverse-engineer, though it would be a bit of a pain.
BTW is a full end-user recalibration possible ( this would make reversing the cal data easier if nothing else)?
So, IDA and I have been having a bit of fun over the past week and I now have a perhaps 80% complete IDA database of the 1.02 firmware. I'm hesitant to release it because a) it's not done and b) I don't know what UEI would think. I also can't test a lot of theories because my own meter is not here yet.
Anyway, regarding the format of the firmware file. The CPU is an STM32L152 family Cortex-M3 ARMv7-M processor. I don't know what exact chip it is. If anyone could send me a photo of the exact chip in the meter, I would be grateful. The EEVBlog.bin file is burned into ROM starting at 0x08006000. It has a standard Cortex-M3 vector table at the start, where the first 32 bits are the initial SP and the second are the reset vector (+ 1 because the processor always operates in Thumb-2 mode). This is enough to get it disassembling correctly in IDA, or to start your own firmware once the exact chip is known.
Regarding calibration data, it actually seems possible to load and save the calibration area of the EEPROM to the SD card. As before, I can't test it cause I don't have a meter. There is a non-zero chance you could lose all your cal data or start a fire. If you want to try, here is the procedure:The cal.bin file is a copy of the first 1200 bytes of EEPROM. The first 48 bytes are used for settings, the rest of the 1200 bytes is calibration factors, and the rest of the EEPROM is involved with logging.
- Boot holding the MEM key, or maybe boot the meter with no keys and quickly press MEM. (I'm not entirely sure) Screen will show SdCAL if you did it.
- Press PEAK to load calibration data from SD card (screen shows SdSEt) or REL to save data to card (screen shows SdSAv).
- Press MODE to do it. If successful, screen shows SAvEd. Else, screen shows -Err-.
- Turn off the meter. The data is now in cal.bin on the SD card.
A lot of the ranges share factors and there are some I'm not too sure about. The official manual is pretty light on details, and it seems there are other things such as a bonus 50Mohm range calibration and some frequency calibration factors for the AC ranges which are not mentioned. (And what's with 10% for the AC ranges? Is that 10% of full scale as opposed to a dead short?) Fortunately, for most modes and ranges, it is indeed a simple 0 offset and a full-scale gain and I know which ones use which factors. Sadly, I'm not a metrologist, and these areas are heavy on algorithms I don't understand, so I'm having trouble. But I intend on communicating whatever I learn when I do learn it.
And Dave, could you give me an OK/over my dead body on releasing the work?
I just uploaded a video...
Maybe start a new hacking thread?
Maybe start a new hacking thread?
There is already one: https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/ (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/)
Any word on publishing the format of the cal data and firmware files - these would be prerequisites for alternative firmware - probably possible to reverse-engineer, though it would be a bit of a pain.
BTW is a full end-user recalibration possible ( this would make reversing the cal data easier if nothing else)?
So, IDA and I have been having a bit of fun over the past week and I now have a perhaps 80% complete IDA database of the 1.02 firmware. I'm hesitant to release it because a) it's not done and b) I don't know what UEI would think. I also can't test a lot of theories because my own meter is not here yet.
Anyway, regarding the format of the firmware file. The CPU is an STM32L152 family Cortex-M3 ARMv7-M processor. I don't know what exact chip it is. If anyone could send me a photo of the exact chip in the meter, I would be grateful. The EEVBlog.bin file is burned into ROM starting at 0x08006000. It has a standard Cortex-M3 vector table at the start, where the first 32 bits are the initial SP and the second are the reset vector (+ 1 because the processor always operates in Thumb-2 mode). This is enough to get it disassembling correctly in IDA, or to start your own firmware once the exact chip is known.
Regarding calibration data, it actually seems possible to load and save the calibration area of the EEPROM to the SD card. As before, I can't test it cause I don't have a meter. There is a non-zero chance you could lose all your cal data or start a fire. If you want to try, here is the procedure:The cal.bin file is a copy of the first 1200 bytes of EEPROM. The first 48 bytes are used for settings, the rest of the 1200 bytes is calibration factors, and the rest of the EEPROM is involved with logging.
- Boot holding the MEM key, or maybe boot the meter with no keys and quickly press MEM. (I'm not entirely sure) Screen will show SdCAL if you did it.
- Press PEAK to load calibration data from SD card (screen shows SdSEt) or REL to save data to card (screen shows SdSAv).
- Press MODE to do it. If successful, screen shows SAvEd. Else, screen shows -Err-.
- Turn off the meter. The data is now in cal.bin on the SD card.
A lot of the ranges share factors and there are some I'm not too sure about. The official manual is pretty light on details, and it seems there are other things such as a bonus 50Mohm range calibration and some frequency calibration factors for the AC ranges which are not mentioned. (And what's with 10% for the AC ranges? Is that 10% of full scale as opposed to a dead short?) Fortunately, for most modes and ranges, it is indeed a simple 0 offset and a full-scale gain and I know which ones use which factors. Sadly, I'm not a metrologist, and these areas are heavy on algorithms I don't understand, so I'm having trouble. But I intend on communicating whatever I learn when I do learn it.
And Dave, could you give me an OK/over my dead body on releasing the work?
Maybe start a new hacking thread?
There is already one: https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/ (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/)
Surprised you didn't mention the burden voltage on the 121's secondary display. I see you didn't hook it up in the video, but would have been nice to compare it's value with the other meters.
thanks
Anyway, regarding the format of the firmware file. The CPU is an STM32L152 family Cortex-M3 ARMv7-M processor. I don't know what exact chip it is. If anyone could send me a photo of the exact chip in the meter, I would be grateful.See here https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1406994/#msg1406994] [url]https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1406994/#msg1406994 (http://[url)[/url]
I am having ....
Roger, this should help. *edit (but you'll have to pull the jpg from the phones DCIM folder and copy or send it to a PC - YMMV)I am having ....
Can I ask a stupid question - how did you get that screen shot ?
thanks
Feature request
Could you include an option in the setup to disable the beeper? It's fine for power-on events and continuity testing etc... but it becomes more of an annoyance every time you turn the knob or press a button. I understand the reasoning behind it, but for me, I'd prefer to have the option to turn it off for key presses/mode changes (or at least select a lower volume).
OFF-LOW-MED-HI options would be fantastic.
Can probably reprogram the beep with a pair of wire cutters >:D
Can probably reprogram the beep with a pair of wire cutters >:D
Yes, I may have to resort to that. Otherwise my wife may reprogram it "up the side of my head"....
Can probably reprogram the beep with a pair of wire cutters >:D
Yes, I may have to resort to that. Otherwise my wife may reprogram it "up the side of my head"....
I just want to clarify, I want the beep on power-up and continuity, just no other time.
I have v1.04
I don't know why they can't at least partially use the bargraph ADC for this.
Ohms autoranging has been improved down to just under 4.5sec or so. They claim any faster and the meters would require recalibration. I don't know why they can't at least partially use the bargraph ADC for this.Great news. 8)
I have v1.04
Negative VA issue supposed to be fixed (haven't checked)
Beep is now off by default.
Ohms autoranging has been improved down to just under 4.5sec or so. They claim any faster and the meters would require recalibration. I don't know why they can't at least partially use the bargraph ADC for this.
Ohms autoranging has been improved down to just under 4.5sec or so. They claim any faster and the meters would require recalibration. I don't know why they can't at least partially use the bargraph ADC for this.Great news. 8)
Will it be further reduced for the 2nd batch? Calibration will not be a problem since it would be from the factory.
I suspect the limiting factor may be the time it takes to settle after re-ranging, rather than actual acquisition rate or any code speed limitations, though it may also be doing stupid things like excessive screen redrawsOhms autoranging has been improved down to just under 4.5sec or so. They claim any faster and the meters would require recalibration. I don't know why they can't at least partially use the bargraph ADC for this.Great news. 8)
Will it be further reduced for the 2nd batch? Calibration will not be a problem since it would be from the factory.
The speed is basically based on algorithm used, a binary tree search would result in log(n) base2 where as linear (n). For example if linear search was taking 7 sec to reach extreme end (lowest range), then after binary search you can basically reduce time to 2.8 sec (log base 2 of 7 is 2.807355)
Now Dave is saying it is 4.5 sec, with a improved algorithm it can reduce to 2.16 sec. There are many ways to improve firmware speed, essentially they need to profile the code, reduce string copies if any, use all constant time data structures, remove unwanted calls to memory allocator (rather use object pools), check for cache hit analysis .. use simple array structures when possible and so on.
If they can install valgrind under quemu (if thats ported to STM32) you can do a much detailed profiling of the code. That way you can optimize the portions that are slowing down the meter. Not only it will make it run faster, it will also increase battery :)
The speed is basically based on algorithm used, a binary tree search would result in log(n) base2 where as linear (n). For example if linear search was taking 7 sec to reach extreme end (lowest range), then after binary search you can basically reduce time to 2.8 sec (log base 2 of 7 is 2.807355)
The speed is basically based on algorithm used, a binary tree search would result in log(n) base2 where as linear (n). For example if linear search was taking 7 sec to reach extreme end (lowest range), then after binary search you can basically reduce time to 2.8 sec (log base 2 of 7 is 2.807355)
There are many ways to improve firmware speed, essentially they need to profile the code, reduce string copies if any, use all constant time data structures, remove unwanted calls to memory allocator (rather use object pools), check for cache hit analysis .. use simple array structures when possible and so on.
If they can install valgrind under quemu (if thats ported to STM32) you can do a much detailed profiling of the code. That way you can optimize the portions that are slowing down the meter. Not only it will make it run faster, it will also increase battery :)
I suspect the limiting factor may be the time it takes to settle after re-ranging, rather than actual acquisition rate or any code speed limitations, though it may also be doing stupid things like excessive screen redraws
The front end chip has a slow and a fast ADC. No need to figure out how to trick the slow if the fast is available. Is the fast ADC used for the bargraph?
The trick will be to short-circuit the A->D conversions and switch range as soon as possible when you see the range is obviously wrong (eg. look at the initial slope of the ADC charge curve?)
Another data point : I have a meter here using the same chip that ranges from open to 0R in 2 seconds.
One aspect of autoranging with a faster but lower precision ADC is that the meter might select a range that is not optimal.
You could always detect that and change range... :popcorn:Yes, there are several options.
I wonder what clock rate the HY3131 in 121GW is running? - typical is 4.9152MHz but max is 8.0MHz according to the datasheet. If higher clock rate would mean faster auto-ranging (my guess is that it would) but then also less battery life - I would really go for faster auto-range as long as the 121GW has a auto-power off function.
I'd like the option of recal to even further reduce the auto ranging time. :-+
Any news on the US meters?
I'd like the option of recal to even further reduce the auto ranging time. :-+
There are production meters in the field now, so we can't release firmware that would break the calibration, that would be very foolish.
Does the US batch include the EU ones that didn't pre-pay VAT? - ISTR you said some other countries were being fulfilled via US.Any news on the US meters?
Yes, sorry but the US meters will be delayed, they want to make some small tolerance changes to the range switch. We'd rather have them delayed a bit than to have any more potential range switch issues.
I wonder what clock rate the HY3131 in 121GW is running? - typical is 4.9152MHz but max is 8.0MHz according to the datasheet. If higher clock rate would mean faster auto-ranging (my guess is that it would) but then also less battery life - I would really go for faster auto-range as long as the 121GW has a auto-power off function.
It's 4.9152MHz
And I don't think that's how it work, it doubt it would magically make the autoranging faster. The micro controls the autoranging, not the HY3131.
Does the US batch include the EU ones that didn't pre-pay VAT? - ISTR you said some other countries were being fulfilled via US.
One would of-course put this FW behind a warning of such. If the improvement is negligible then who cares, but if significant it would be a shame to censor it for those of us capable of a full cal, which could be quite a few as we now pass cal standards around.I'd like the option of recal to even further reduce the auto ranging time. :-+
There are production meters in the field now, so we can't release firmware that would break the calibration, that would be very foolish.
I see an app in the iOS App store called "EEVBlog 121GW" by Cheon Myoung-kun. That doesn't sound legit, does it?
And it looks bloody awfull. :wtf:
Almost all users do not have the ability to calibrate the meter themselves, and you would be effectively forcing those users to do that if they wanted to upgrade their firmware in the future. That would be very poor form.
I see an app in the iOS App store called "EEVBlog 121GW" by Cheon Myoung-kun. That doesn't sound legit, does it?
And it looks bloody awfull. :wtf:
It is bloody awful which is why we wrote our own. But yes it is "legit". UEi got that person to write it.
Any news on the US meters?
Yes, sorry but the US meters will be delayed, they want to make some small tolerance changes to the range switch. We'd rather have them delayed a bit than to have any more potential range switch issues.
Any news on the US meters?
Yes, sorry but the US meters will be delayed, they want to make some small tolerance changes to the range switch. We'd rather have them delayed a bit than to have any more potential range switch issues.
How is the range switch modification going to be implemented? Who is doing the replacement for the US meters, and will you send replacement parts to customers who've already received theirs?
The switch on my meter (#000499) is also wobbly and has the problem described here.
I took it apart, and contacts and pcb looked ok. After I put it back together it worked allright for a while, but now it's back and I have to fiddle with the switch again to get it to display correct readings. :-BROKE
Dave, once UEi figures out a fix, will you send out a replacement part?
Yes we'll have to do that for those existing shipments who have problems.
Presumably the cal issue is that they need to do measurement differently, so different cal data is needed.
This could be handled by the firmware looking to see if the new format data is present, and only using the newer ranging method if so. A user could choose to recal to enable this if they have the facility.
Another approach for a user to recal would be simply to use old FW to set a multiturn trimmer to the required cal value, update the FW, then use the trimmer to recal.
Ok, so your saying the meters are now in the US, and UEI is taking them to fix the range switches. Will UEI be shipping them, or will they get shipped again to the reshipper in the US and then make it to the customers. Or did you can the reshipper and UEI will be shipping the US meter now?
I have an idea, it’s not uncommon to have 2 different firmwares for different hardware releases.
As a “Thank you for being patient” can the US customers request maybe UEI can update the auto range speed on the US meters and mark them hardware version 1.1. Since it will be at the manufacturer I’m sure they can calibrate for the faster update ranging. Going forward for new batches can also all be marked as HW1.1 with the faster range update.
And for those that have the ability to calibrate the meter they can also load hardware version 1.1 firmware and do the calibration themselves.
Another approach for a user to recal would be simply to use old FW to set a multiturn trimmer to the required cal value, update the FW, then use the trimmer to recal.
Here is the schematic which may helpWhy are Q13/Q16 (and Q14/Q15 if they were populated) used ?
David2 is working on seeing what we can provide in terms of documentation to help people who want to write their own firmware.
http://www.eevblog.com/files/121GW%20EEVBlog%20Circuit%20diagram.pdf (http://www.eevblog.com/files/121GW%20EEVBlog%20Circuit%20diagram.pdf)
Regarding the specs of the meter, in the manual it lists the ranges:
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=389136)
So what is the resolution and accuracy for 501uA to 4999uA?
Range | Resolution, Accuracy | Burden Voltage |
50 µA | 1 nA, ±1.5%+15 | 100 µV/µA |
500 µA | 10 nA, ±1.5%+15 | 100 µV/µA |
5 mA | 0.1 µA, ±0.25%+5 | 2 mV/mA |
50 mA | 1 µA, ±0.25%+5 | 2 mV/mA |
0.5 A | 10 µA, ±0.75%+15 | 0.03 V/A |
10 A | 1 mA, ±0.75%+15 | 0.03 V/A |
The rev 1705 and 1720 from your "121GW Final Test Unit Inspection" video had U14 for example.Are you referring to the video with them all on the table, and the close up shots? I saw that one as 1745 with u14 missing also. Or are you referring to another video?
Regarding the specs of the meter, in the manual it lists the ranges:
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=389136)
So what is the resolution and accuracy for 501uA to 4999uA?
They use the 5mA range.
You are missing something. Multimeter specifications always refer to the ranges - not to currents or voltages you are measuring. So this table is talking about the 50uA to 10A ranges.Regarding the specs of the meter, in the manual it lists the ranges:
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=389136)
So what is the resolution and accuracy for 501uA to 4999uA?
They use the 5mA range.
If that is the case, why is it listed as 5 to 50 mA instead of that actual range of 0.5 to 50mA? Am I missing something simple here? ???
The video I'm referring to is unlisted, but easy to find by its title.The rev 1705 and 1720 from your "121GW Final Test Unit Inspection" video had U14 for example.Are you referring to the video with them all on the table, and the close up shots? I saw that one as 1745 with u14 missing also. Or are you referring to another video?
Dave did say that they had to tidy up the schematic before they could release it. When you tidy up a document, that is a change and so the revision must increase. We do not know why the tidy up was needed - it might be just removing confidential information like employees names.The video I'm referring to is unlisted, but easy to find by its title.The rev 1705 and 1720 from your "121GW Final Test Unit Inspection" video had U14 for example.Are you referring to the video with them all on the table, and the close up shots? I saw that one as 1745 with u14 missing also. Or are you referring to another video?
But those older revision don't really matter, it's just to show there are differences, and not limited to the changes needed to pass certification.
What matters is we have rev 1745 meters, so perhaps we need rev 1745 schematic, and not rev 1752 which might be different.
The circuit will be either accurate, or pretty close to accurate.
The meters of "Johnie be good" for Europe via the Germany company, will include the switch tweak?
Presumably the cal issue is that they need to do measurement differently, so different cal data is needed.
This could be handled by the firmware looking to see if the new format data is present, and only using the newer ranging method if so. A user could choose to recal to enable this if they have the facility.
Another approach for a user to recal would be simply to use old FW to set a multiturn trimmer to the required cal value, update the FW, then use the trimmer to recal.
Right, no need to maintain two different firmware versions, just a small portion of the firmware has to handle the old and new format. I hope they are experienced firmware developers who versioned the calibration data, because such things always change. But even if they didn't, it shouldn't be a problem: just use something impossible for the old format as the first byte for the new calibration data, to mark it as the new format. Fortunately it doesn't have to be compatible in the other direction, like there is nobody who would use a new set of calibration data with the old firmware. Could be programmed in like an hour.
@DaveJ: will you publish a list at a certain moment which lists the confirmed issues?
To do so would require screwing existing customers, or maintaining two version of the firmware. Either solution is not acceptable.
Thank you for the diagram! Some of the parts are not specified or listed in a separate table. Is this on purpose?AFAIK, the components with an "x" value aren't populated on the PCB.
At the end of the day if the meter is slow it will greatly impact future sales.I think this is a very good point. To hinder performance for all future meters doesn't seem the best decision either.
So the Bluetooth Module is not used in the released meter. :-DD
At the end of the day if the meter is slow it will greatly impact future sales.I think this is a very good point. To hinder performance for all future meters doesn't seem the best decision either.
I think you need to find out more details of the exact reason - maybe "require recal" just means "requires rewriting code we can't be arsed to do"Right, no need to maintain two different firmware versions, just a small portion of the firmware has to handle the old and new format. I hope they are experienced firmware developers who versioned the calibration data, because such things always change. But even if they didn't, it shouldn't be a problem: just use something impossible for the old format as the first byte for the new calibration data, to mark it as the new format. Fortunately it doesn't have to be compatible in the other direction, like there is nobody who would use a new set of calibration data with the old firmware. Could be programmed in like an hour.
It might not be that easy.
It might affect calibration of other ranges, because (guessing) it might use a common ADC read averaging routine or something. What if you have to recalibrate the whole meter.
I really think this is bad idea and I am loath to recommend such a thing.
a large potential difference would certainly blow up some ICs.
I wonder if someone could check the meter in the LowZ mode. In the early unit, if I applied a 1VRMS 60Hz signal, the meter would read zero as expected. However, when I would increase the frequency to 389KHz, the meter was displaying 181.3 volts even though there was still only a volt being supplied. There was something strange going on with it that I never looked into. I reported the problem when I discovered it but with as many problems that the meter still has, I wonder if this was addressed in the released version.
I wonder if someone could check the meter in the LowZ mode. In the early unit, if I applied a 1VRMS 60Hz signal, the meter would read zero as expected. However, when I would increase the frequency to 389KHz, the meter was displaying 181.3 volts even though there was still only a volt being supplied.
I think you need to find out more details of the exact reason - maybe "require recal" just means "requires rewriting code we can't be arsed to do"
Dave posted the schematic in the firmware thread, but I reply here since my questions would be off-topic there :Here is the schematic which may helpIs it safe to let 4053 logic input pins floating (C pin of U11, A pin of U14 if it was populated) ?
http://www.eevblog.com/files/121GW%20EEVBlog%20Circuit%20diagram.pdf (http://www.eevblog.com/files/121GW%20EEVBlog%20Circuit%20diagram.pdf)
Usually it's not recommended, so unless the 4053 is special it's strange.
I've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
Yes that seems strange - C is pin9 on U11 and is a digital cmos input and really shouldn't be left floating. Schematics error? should it be connected to A and B which already are connected together.I don't see any obvious trace connected to the pin.
Oh man... can't wait for firmware version ...
v1.21
I hope it includes some serious shit!
You are missing something. Multimeter specifications always refer to the ranges - not to currents or voltages you are measuring. So this table is talking about the 50uA to 10A ranges.
I've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
Ranges on multimeters are always specified with the upper limit. The lower limit is always 0. So with the 5V range you can measure from 0V to +-5V. But to get a meaningful measurement, you need to have enough resolution to discern values at the lower end. A 50000 count DMM, like this one, will have a resolution of 0.0001V or 100 uV on the 5V range. So you can measure only discrete values from 0 to +-5V in 100uV steps.You are missing something. Multimeter specifications always refer to the ranges - not to currents or voltages you are measuring. So this table is talking about the 50uA to 10A ranges.
Thanks amspire, that makes sense and it is what I see in the manual for my fluke, but what I still don't get is, why is the range specified with the lower value, so the 5mA value, when it can measure down to 500uA?
Thanks amspire, that makes sense and it is what I see in the manual for my fluke, but what I still don't get is, why is the range specified with the lower value, so the 5mA value, when it can measure down to 500uA?
Range | Resolution, Accuracy | Burden Voltage |
50 µA | 1 nA, ±1.5%+15 | 100 µV/µA |
500 µA | 10 nA, ±1.5%+15 | 100 µV/µA |
5 mA | 0.1 µA, ±0.25%+5 | 2 mV/mA |
50 mA | 1 µA, ±0.25%+5 | 2 mV/mA |
0.5 A | 10 µA, ±0.75%+15 | 0.03 V/A |
10 A | 1 mA, ±0.75%+15 | 0.03 V/A |
I've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
If you upload the firmware file then we can test it.
I'd get you a meter, but we only have two production units left here.
I've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
If you upload the firmware file then we can test it.
I'd get you a meter, but we only have two production units left here.
Sure, as long as I'm not responsible for any possible bodily harm as a result :) And thanks for the note, I do understand you need to keep those. But I leave the country in a month and I'm worried I won't get a meter before then as I'm in the US group. I'd really like one to continue hacking on, it's been fun so far.
For the patch, I just made the autorange routine ignore the mode/range change delay if the last mode/range change was caused by autoranging. It might just oscillate wildly, who knows! If it does work, it could more than halve autorange time.
I've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
If you upload the firmware file then we can test it.
I'd get you a meter, but we only have two production units left here.
Sure, as long as I'm not responsible for any possible bodily harm as a result :) And thanks for the note, I do understand you need to keep those. But I leave the country in a month and I'm worried I won't get a meter before then as I'm in the US group. I'd really like one to continue hacking on, it's been fun so far.
For the patch, I just made the autorange routine ignore the mode/range change delay if the last mode/range change was caused by autoranging. It might just oscillate wildly, who knows! If it does work, it could more than halve autorange time.
Works! :clap:
I compared UEi's v1.04 and it's only a smidgen slower, not even half a second.
https://www.youtube.com/watch?v=3MD88EYLdQQ (https://www.youtube.com/watch?v=3MD88EYLdQQ)
The company should hire tpw_rules. Pretty amazing to hack the binary without the source code and not even a meter for testing. Imagine what he could do if he would have the hardware and the source code :)
It's clearly doing some stuff it doesn't need to though - you see some intermediate displays during rangingI've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
If you upload the firmware file then we can test it.
I'd get you a meter, but we only have two production units left here.
Sure, as long as I'm not responsible for any possible bodily harm as a result :) And thanks for the note, I do understand you need to keep those. But I leave the country in a month and I'm worried I won't get a meter before then as I'm in the US group. I'd really like one to continue hacking on, it's been fun so far.
For the patch, I just made the autorange routine ignore the mode/range change delay if the last mode/range change was caused by autoranging. It might just oscillate wildly, who knows! If it does work, it could more than halve autorange time.
Works! :clap:
I compared UEi's v1.04 and it's only a smidgen slower, not even half a second.
https://www.youtube.com/watch?v=3MD88EYLdQQ (https://www.youtube.com/watch?v=3MD88EYLdQQ)
It's clearly doing some stuff it doesn't need to though - you see some intermediate displays during rangingI've made a patch which removes that mode/range change delay while autoranging, but I can't test it without a meter. I'm now wondering if anybody would be willing to sell me their meter for testing purposes?
If you upload the firmware file then we can test it.
I'd get you a meter, but we only have two production units left here.
Sure, as long as I'm not responsible for any possible bodily harm as a result :) And thanks for the note, I do understand you need to keep those. But I leave the country in a month and I'm worried I won't get a meter before then as I'm in the US group. I'd really like one to continue hacking on, it's been fun so far.
For the patch, I just made the autorange routine ignore the mode/range change delay if the last mode/range change was caused by autoranging. It might just oscillate wildly, who knows! If it does work, it could more than halve autorange time.
Works! :clap:
I compared UEi's v1.04 and it's only a smidgen slower, not even half a second.
https://www.youtube.com/watch?v=3MD88EYLdQQ (https://www.youtube.com/watch?v=3MD88EYLdQQ)
The company should hire tpw_rules. Pretty amazing to hack the binary without the source code and not even a meter for testing. Imagine what he could do if he would have the hardware and the source code :)NO ! NO ! NO ! Don't let UEI steel him. tow_rules should stay on the open source side and help us to not only get a more awesome meter but understand how it works! I am really impressed :)
Acts like everything is fine set on volts with both leads plugged in A/mA
Strange. Maybe someone missed an OR statement. Just an added bit of info, both the Fluke 189 and Brymen BM869s will fault out under this condition.
...
Yup, they missed it. Code is here (https://github.com/tpwrules/121gw-re/blob/e0a0d88c952e8e1e61eedb4d6fb0b3b62a58be6a/database/EEVBlog-102.c#L14754). v0 is 0 if nothing's plugged in, 1 if mA is, 2 if A is, and 3 if both. They assume everything is OK if 0, or if 3. Maybe the hardware won't do the correct thing in case both are plugged in so they didn't check. I don't really understand how it's sensing a plug.
I use the AC+DC mode. On the pre-production meter, this never worked very well. If you wanted to try something very simple, switch the meter to AC+DC. Attache the two leads normally (volts and common). Now attach a DC supply and set it between 5 and 30 volts. Does the meter just continue to hunt? If it does, take the supply to 40-50 volts. Does it now read correctly? If it does, try lowering the voltage is see if it again starts to hunt. Surely the released meters AC+DC mode works.
Are you both using the same firmware?I have the 1.02 with the auto range patch installed and I can reproduce the exact same behavior as you showed in the video with the pre-production meter.
Are you both using the same firmware?
The pre-production meter would lock in depending on the AC and DC components. If you have a cheap power supply with a lot of ripple for example, the meter may actually read correctly.
Just want to add that rotary switch wobble issue exists also with my meter (EU shipped). https://youtu.be/pjaWWMoPMsE
Is this same for everyone or only part of the already shipped meters?
First, thank you for taking these pictures! Don't tell me that's a section of solder stuck to the bottom of the spring??No it's part of the spring. I already re-soldered it.
Did you notice what appears to be metallic contamination around your pads? It would be nice to get a better shot of this area with a microscope or macro lens.Maybe next week or someone else can have a closer look on his meter.
I don't like that you are already seeing what appears metallic dust this early. Maybe it's something in the lighting.I did not use any flash, only room light (very strong cold LED at the ceiling and warm LED on the bench) what is not the best for taking neutral pictures. I was surprised myself to see that much dust after only some turns. I may have a second nearer view if I find some time the next days. Hopefully someone else can make some pictures to compare.
Isn't one of the selling points is that it can be turned with one hand?
So far no one has said that if there was no wobble, if it could or not be used with one hand.
Just tested it. AUTO DC+AC mode and I supplied about 25Vdc and it hunts. Raised voltage to about 44Vdc and it reads correctly. Lowering the DC voltage and it hunts again.
It looks like all pre-production errors are still present in the first batch of production meters of the 121GW. Even my crappy UNI-T UT71E is doing a better job in all of the discussed bugs.
I like to hear something soon from Dave how they will go on with the production meters of the early adopters... :-\
Strange. You would think it would do it or it wouldn't. I am not sure what sort of regression testing is being ran on the patched code. Maybe the patch has something to do with it.Are you both using the same firmware?
The pre-production meter would lock in depending on the AC and DC components. If you have a cheap power supply with a lot of ripple for example, the meter may actually read correctly.
V1.02 original (no autoranging patch)
Isn't one of the selling points is that it can be turned with one hand?
So far no one has said that if there was no wobble, if it could or not be used with one hand.
If so, probably only after Dave realised early on that is was never going to be as stiff as the BM235 (which was a selling point about how stiff it was, and any shootout would get extra point for stiffness), and quickly turned a negative into a positive. I think we underestimate how good he is at the marketing, and his own down playing of this skill, is a key part. I would bet, if he could have got them to make it as stiff, he would have.
I am having problems with connecting the 121GW app from dave2. I did no get any data shown in the app up to now. Most time it even does not connect.
I first run bluetooth and connect to the 121GW then I start the app. Sometimes when I click on refresh I can see the 121GW. Only one time it was able to connect (but no data shown, only white screen). Most time it says "connecting..." but never does.
The other app "EEVBlog 121GW" sometimes connects successfully and shows some values but sorry, it's so ugly.
/EDIT:
Now I got it running for one time but I think I am missing some data on the screen?
Well it was not a cheap power supply at 500€ but will try with a 9V battery then later. I’ve so far not se3n what you show in your viceo. Anyone else?
Just want to add that rotary switch wobble issue exists also with my meter (EU shipped). https://youtu.be/pjaWWMoPMsEMine (#000499) is similar, maybe a bit less.
Is this same for everyone or only part of the already shipped meters?
Hi Joe, I just tried it and can not replay your issue in the video. 10Vpp sine-wave from the Siglent SDG 2042X into the 121GW and the BM869s connected too. This 121GW on any ms range indicates correctly at frequencies from 10Hz to 200Hz (10, 50, 100, 200). I can not get a wrong reading on the meter. Still on V1.02 not patched for slow update rate.9V I assume was for the AC+DC mode. If you read the previous posts, looks like the reason for the difference was indeed the patch. It appears they did address a few of the problems. I think the big one is what appears to be a metallic dust in those previous pictures. If you have been putting a few cycles on yours (even a few hundred total) and a camera that you can take some close ups of the pad area, it would be interesting to see a few more pictures.Well it was not a cheap power supply at 500€ but will try with a 9V battery then later. I’ve so far not se3n what you show in your viceo. Anyone else?
Hi Joe, tried a 9v (actually bit dated and went to 8v) battery. Apart from slow auto-ranging no issue on locking in. So if slow auto-ranging is hunting then yes but I assume not.
Personally, I would rather know if there was a problem early on. If there is, maybe it could be corrected before any major damage happens to the PCB. What sort of warranty did you get? If you put a few thousand cycles on the switch over the next few weeks and the parts are damaged, is the meter covered?Hi Joe, I just tried it and can not replay your issue in the video. 10Vpp sine-wave from the Siglent SDG 2042X into the 121GW and the BM869s connected too. This 121GW on any ms range indicates correctly at frequencies from 10Hz to 200Hz (10, 50, 100, 200). I can not get a wrong reading on the meter. Still on V1.02 not patched for slow update rate.9V I assume was for the AC+DC mode. If you read the previous posts, looks like the reason for the difference was indeed the patch. It appears they did address a few of the problems. I think the big one is what appears to be a metallic dust in those previous pictures. If you have been putting a few cycles on yours (even a few hundred total) and a camera that you can take some close ups of the pad area, it would be interesting to see a few more pictures.Well it was not a cheap power supply at 500€ but will try with a 9V battery then later. I’ve so far not se3n what you show in your viceo. Anyone else?
Hi Joe, tried a 9v (actually bit dated and went to 8v) battery. Apart from slow auto-ranging no issue on locking in. So if slow auto-ranging is hunting then yes but I assume not.
Hi Joe, I'll give that a go the coming days. Too much normal work going on for me at the moment. I'm not sure I'm looking forward to this to be honest. If the tracks are or seem to deteriorate quickly I would be appalled. Are you getting an official, non pre-production, 121GW soon perhaps?
From what I understand, very few meters made it to people in the USA so even if I had joined, I doubt I would have it. Strange as I would have thought they would have been the largest consumer. Anyway, I was concerned that there had not been a full review of the meter that disclosed what the problems were and how they would be mitigated. Obviously, there were problems that have been known for some time. I had asked a question in the kickstarter that went unanswered. Also, looking at the closeup video, it appeared the meter's weak front end was still in play. Again, it's not a lot of money but if I bought one it would be to run it to failure and I did not want to invest this amount of time if the design was still not stable or if it was not going to be an improvement over the earlier version. If and when it looks like the meter is stable and it becomes available through normal channels, I may run one. For now, it seems it is way too early.
....Keysight U1461A .... goes from infidelity to zero ohms in just 2.2-2.4 sec
....Keysight U1461A .... goes from infidelity to zero ohms in just 2.2-2.4 sec
HA! I thought infidelity was already due to low resistance
From what I understand, very few meters made it to people in the USA so even if I had joined, I doubt I would have it. Strange as I would have thought they would have been the largest consumer.
No... The US meters were simply stuck in customs all the way up to when the switch tolerance issue was reported. Now they won't ship until that issue is fixed.From what I understand, very few meters made it to people in the USA so even if I had joined, I doubt I would have it. Strange as I would have thought they would have been the largest consumer.
Probably the large time difference between USA and Australia caused potential consumers to be too late in the game - at least for the first batch anyway.
Look at the data. There are several meters that have done very well in these tests. 2KV is lower than the average and not something I would be impressed with. I was just as surprised by the Fluke 87V result. Received a lot of negative posts over that one from the fans. Not much I can say about how the meter's do in the tests. I can say that the Fluke 87V is not what I consider the goal post.
Perhaps sniffing the bus on how U1461A controls the hy3131 could give an idea how it achieves this speed. But if we're unlucky there are other HW differences that makes the 121gw so dreadfully slow.
Perhaps sniffing the bus on how U1461A controls the hy3131 could give an idea how it achieves this speed. But if we're unlucky there are other HW differences that makes the 121gw so dreadfully slow.
FYI, the 121GW is now on par with the U1282A.
As I have mentioned before, I really don't know what the failure rate is for the 87V. I've seen posts where they have failed which is not too surprising. Enough hype and marketing can easily cover up any short comings. You are right that there are people that that care less about the marketing and more about the results. I certainly classify myself in that category and offer these test results as proof of that.Look at the data. There are several meters that have done very well in these tests. 2KV is lower than the average and not something I would be impressed with. I was just as surprised by the Fluke 87V result. Received a lot of negative posts over that one from the fans. Not much I can say about how the meter's do in the tests. I can say that the Fluke 87V is not what I consider the goal post.
I guess this goes to show how important this stuff actually is in the real world, as much as we all like to fuss over these sorts of details because, you know, we are nerds.
I have never heard a single person complain that the Fluke 87 series isn't a robust industrial meter, and not surprising because it's been an industry standard for like 30 years now.
As I have mentioned before, I really don't know what the failure rate is for the 87V. I've seen posts where they have failed which is not too surprising. Enough hype and marketing can easily cover up any short comings.Look at the data. There are several meters that have done very well in these tests. 2KV is lower than the average and not something I would be impressed with. I was just as surprised by the Fluke 87V result. Received a lot of negative posts over that one from the fans. Not much I can say about how the meter's do in the tests. I can say that the Fluke 87V is not what I consider the goal post.
I guess this goes to show how important this stuff actually is in the real world, as much as we all like to fuss over these sorts of details because, you know, we are nerds.
I have never heard a single person complain that the Fluke 87 series isn't a robust industrial meter, and not surprising because it's been an industry standard for like 30 years now.
Perhaps sniffing the bus on how U1461A controls the hy3131 could give an idea how it achieves this speed. But if we're unlucky there are other HW differences that makes the 121gw so dreadfully slow.
FYI, the 121GW is now on par with the U1282A.
Perhaps sniffing the bus on how U1461A controls the hy3131 could give an idea how it achieves this speed. But if we're unlucky there are other HW differences that makes the 121gw so dreadfully slow.
FYI, the 121GW is now on par with the U1282A.
FYI, that still makes it dreadfully slow - I’m sorry, but I guess I miss the old clonk-clonk-clonk Dave who’d facepalme and hammer his failbutton through the desk if confronted with an auto-ranging this slow on a DMM in this class. But still I really do appreciate what you’re trying to provide with the 121gw and my main point was that the U1461 was so much faster in a 6000 count mode.
Am I expecting UEi to provide a fast 5000 count mode for 121gw? - no not really - but they’re in a much better position having the FW source code to make an addition like that - compared to hacking/patching the binaries. But I’m starting to wonder if UEi them self is limited in what they can achieve with the development tools they’re using. Else I can’t really understand why 121gw ever was released with an auto-raging that was so slow that backers would go seriously WTF!
Appears to have less contamination but we have no idea how many cycles were on the two meters posted so far. Can you tell with your eyes if any of that is metallic?
I wonder how the people with the intermittent switches would compare with the ones the work as expected. It would seem that the intermittent meters make have less contact force and would be less prone to wear but we really don't know.
Appears to have less contamination but we have no idea how many cycles were on the two meters posted so far. Can you tell with your eyes if any of that is metallic?I posted the first pictures and checked today. I think it's not metallic at least not magnetic. I checked with a strong neodyn magnet and it doesn't feel metallic.
Practical world sounds like a marketing term. I really have no idea idea about the 87Vs reputation, if it has one or how it came to be.
I also would like to get more updates on the meter. Any rumors, estimations, etc. So, we could see it's not abandoned. If possible. Or, better, a UEI representative here in the thread. Like other manufacturers do on this forum (e.g., MicSig, R&S, Siglent (tautech), Rigol, etc).
IanX,I also would like to get more updates on the meter. Any rumors, estimations, etc. So, we could see it's not abandoned. If possible. Or, better, a UEI representative here in the thread. Like other manufacturers do on this forum (e.g., MicSig, R&S, Siglent (tautech), Rigol, etc).
Dave, I think it is time that you found your voice and provide an update of the current situation!
What progress, (if any) has been made by you and UEi in rectifying the faults?
I am becoming concerned by the lack of communication and wondering if the root cause of the "bugs" is hardware related and only you can provide details on the meter to make clear the situation.
Considerable time has passed without you providing meaningful info on the rectification of the meter's abundant faults.
The meter comes with a warranty and is covered under ACCC laws, but I'm hoping you will be proposing a meter replacement/fix program for the shipped meters and a thorough revision for the meters awaiting manufacture/shipping.
With great respect, what is the current state of play Dave?
I also would like to get more updates on the meter. Any rumors, estimations, etc. So, we could see it's not abandoned. If possible. Or, better, a UEI representative here in the thread. Like other manufacturers do on this forum (e.g., MicSig, R&S, Siglent (tautech), Rigol, etc).
Dave, I think it is time that you found your voice and provide an update of the current situation!
What progress, (if any) has been made by you and UEi in rectifying the faults?
I cant see us hearing from Dave anytime soon as he is keeping a very low profile and with good reason. He cant comment until he has a defined course of action to rectify the bugs and switch issue. Its up to UEi at this stage to pull their finger out and and turn this first "production" run meter into what it should be.
Dave needs to be extremely diplomatic with both his backers/buyers and with UEi. Nothing to be gained by pounding a fist on a table! As much as I dislike the situation with this meter, I am following Dave's lead with patience and high expectations for speedy fix.
Dave, I think it is time that you found your voice and provide an update of the current situation!
What progress, (if any) has been made by you and UEi in rectifying the faults?
I am becoming concerned by the lack of communication and wondering if the root cause of the "bugs" is hardware related and only you can provide details on the meter to make clear the situation.
Considerable time has passed without you providing meaningful info on the rectification of the meter's abundant faults.
The meter comes with a warranty and is covered under ACCC laws, but I'm hoping you will be proposing a meter replacement/fix program for the shipped meters and a thorough revision for the meters awaiting manufacture/shipping.
With great respect, what is the current state of play Dave?
I also would like to get more updates on the meter. Any rumors, estimations, etc. So, we could see it's not abandoned. If possible. Or, better, a UEI representative here in the thread. Like other manufacturers do on this forum (e.g., MicSig, R&S, Siglent (tautech), Rigol, etc).
Dave, I think it is time that you found your voice and provide an update of the current situation!
What progress, (if any) has been made by you and UEi in rectifying the faults?
The issues are being investigated, stuff just takes time, especially when you have more than one issue. There is no point in me speculating daily.
There is essentially very little I can do personally to speed this up or really even help them out from a technical perspective.
They are still waiting on the range switch parts, due in a few days I believe, and then there is testing etc.
On top of that of course are several software issues, some like slow autoranging for example has been solved (to match that of the U1282A), others are still being worked on (presumably one by one).
Please be patient, when I know for certain, you'll know.
This certainly won't be my first or only meter. Whether I get it today, next month or even a few months from now really makes no difference. Sure, I'm looking forward to receiving it because, among other things, it is already paid for. But I would rather have the upgraded switch and firmware rather than try to figure out what to do next. It takes what it takes and getting these issues resolved before it ships to me makes all the sense in the world (to me).
I'm hoping to use this meter for measuring ucurrent on my ESP32 projects. Has anyone used the meter for ucurrent measurement by placing a zero ohm shunt in place of the fuses? If you have tried it what burden voltage was present and how does it compare to the uCurrentGold?
I did apply a small amount of contact type grease in that area but I also made sure the pressure from the sleeve was just enough to mitigate the lateral movement without grossly effecting the rotary movement of the switch.About a week ago I reported the mechanical issue I had on my 121 with the switch and input terminals here ;
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1403241/#msg1403241 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1403241/#msg1403241)
....
The best size for my meter was 6.1mm OD. To help alignment further I made the ID be a good sliding fit to the hex shaft of the knob at 5.6mm.
The resulting sleeve I machined up can be seen in the photo below in its final position (I left it longer so its easily removed.). The material used was PEEK which is
reasonably stiff and has good insulation properties, (I also had it anyway :P). Did not want to use PTFE which would have been too soft at the cross section used.
....
So the end result of this exercise was a considerably less 'wobbly' feel to the knob and more importantly all the issues I had reported have now gone
completely and any movement of the input plugs have no effect on the switch nor does wiggling the knob itself set off any failures of the mode its in.
By adding the sleeve, I wonder if the PCB will wear away at shaft where it rotates in the hole. Time will tell.
I forgot to mention that a couple of days ago I dumped the batteries out of a set top box remote control I need to return and was surprised to see that they were made by UEI. I wonder if the 121GW comes with a UEI battery?For us in Oz it was duracell.
In the following, when I refer to just the "switch", I meant all the parts attached to the circuit board.
So after returning from holiday I thought I would have a look inside at what may be happening with my meter.
What I can see happening with mine to cause my issue was the small flexing of the PCB by the input plugs movement
was causing referred movement at the switch area and since my switch was rather 'sloppy' in its location hole this had caused
either contact or contact location issues on their relevant PCB tracks and thus the mode failures.
Further investigation of the switch rotor showed quite a lot of lateral movement in the PCB locating hole.
So next step was what to do to reduce this lateral 'slop'!.
After removing the PCB from the switch knob I could test fit various rod diameters, (rear ends of twist drills in 0.1mm inc.), to lightly expand
the switch plate plastic fingers that go through the main PCB to remove the slop but still have easy rotational movement.
The best size for my meter was 6.1mm OD. To help alignment further I made the ID be a good sliding fit to the hex shaft of the knob at 5.6mm.
The resulting sleeve I machined up can be seen in the photo below in its final position (I left it longer so its easily removed.). The material used was PEEK which is
reasonably stiff and has good insulation properties, (I also had it anyway :P). Did not want to use PTFE which would have been too soft at the cross section used.
As an additional exercise I also cut up some 0.3mm PTFE sheet as spacers under the knob circlip, see photo below. Two pieces provided a good take up
of the space between the housing and the circlip. This reduced the knob free play up and down but allowed some compliance in the well in the top housing and the circlip too
due to the soft flexible nature of the PTFE.
I wouldn't have expected it to be magnetic but it's good to know.Appears to have less contamination but we have no idea how many cycles were on the two meters posted so far. Can you tell with your eyes if any of that is metallic?I posted the first pictures and checked today. I think it's not metallic at least not magnetic. I checked with a strong neodyn magnet and it doesn't feel metallic.
I cleaned it and will check in some weeks.
In the following, when I refer to just the "switch", I meant all the parts attached to the circuit board. The "switch rotor" is the knob part attached to the case.
So after returning from holiday I thought I would have a look inside at what may be happening with my meter.
What I can see happening with mine to cause my issue was the small flexing of the PCB by the input plugs movement
was causing referred movement at the switch area and since my switch was rather 'sloppy' in its location hole this had caused
either contact or contact location issues on their relevant PCB tracks and thus the mode failures.
Further investigation of the switch rotor showed quite a lot of lateral movement in the PCB locating hole.
So next step was what to do to reduce this lateral 'slop'!.
After removing the PCB from the switch knob I could test fit various rod diameters, (rear ends of twist drills in 0.1mm inc.), to lightly expand
the switch plate plastic fingers that go through the main PCB to remove the slop but still have easy rotational movement.
The best size for my meter was 6.1mm OD. To help alignment further I made the ID be a good sliding fit to the hex shaft of the knob at 5.6mm.
The resulting sleeve I machined up can be seen in the photo below in its final position (I left it longer so its easily removed.). The material used was PEEK which is
reasonably stiff and has good insulation properties, (I also had it anyway :P). Did not want to use PTFE which would have been too soft at the cross section used.
As an additional exercise I also cut up some 0.3mm PTFE sheet as spacers under the knob circlip, see photo below. Two pieces provided a good take up
of the space between the housing and the circlip. This reduced the knob free play up and down but allowed some compliance in the well in the top housing and the circlip too
due to the soft flexible nature of the PTFE.
I decided to fix my 121GW wobbly switch up a while ago, but after looking at the mechanism, I took a very different approach. I did look at your method but I think it was making the situation even worse rather then better mechanically.
First, instead of putting a spacer under the circlip, I put a spacer between the switch rotor and the the nylon detent spring so that the circlip was in contact with the case plastic. This lifts the rotor upwards. I didn't make it tight. I just wanted to stop any signifigant vertical movement. The reason for this method was so that the circlip does not press on the switch at all. If you put spacers under the circlip, the circlip is pressing on the switch which I think is wrong. The spacer was actually just many layers of duct tape. I had a punch to make a nice hole in the middle.
But now the switch rotor was even looser. So I added a few strips of Kapton tape around the switch rotor sides to widen it till it stopped wobbling much. You want to change a cone shape that is narrowest at the top to one widest at the top, so start off with a thin strip of tape just near the top side of the switch rotor. Then a thicker one that goes to 2/3 down the rotor sides. Then some that goes around the whole sides. The idea is to increase the switch rotor diameter to the point it can hardly wobble, but still have a tiny clearance to the case. Correctly done and the switch rotor is no stiffer then before.
A bit of heat (I just used some hot water) to set the Kapton adhesive and it stays in place really well.
The way you have fixed the switch is you are trying to use the switch to stop the rotor from moving which is putting more stress on the switch. It should be the switch rotor that correctly locates the switch. The switch should be free to float a bit.
After this fix, I don't think anyone would notice an issue. I didn't take the tape right to the top and you cannot actually see it at all.
Richard
You are right. I used the words switch rotor when I meant knob. I have corrected it.
For reference when referring to the rotor, that is the plastic carrier for the contact fingers, the PCB is the Stator and the knob would be the 'clicker plate' just like any rotary wafer switch assembly.
Okay when making it worse are you referring to the small sleeve or the PTFE under the circlip ?.I believe that when you put the PTFE under the circlip, then the circlip does push downwards on the switch rotor slightly. Not much deflection, but I don't think anything you do on the knob should be pushing the rotor up and down.
For the sleeve i disagree that any additional stress is being applied to the contacts or the PCB. The dimensions of it are carefully chosen by measurement to only
apply enough pressure to the plastic fingers of the rotor body to the PCB hole reducing only lateral free play ,(which in my opinion is excessive ), to a minimum without
adversely effecting the effort required to rotate. This mechanical change guarantees alignment of the switch contacts on the rotor with the PCB stator and how will this
introduce ant further stress on the contacts.
I just observed some deflection, but I didn't measure the amount. I had already decided to go a different way. The best way to measure this deflection may be to measure the height of the rotor clip above the PCB on the component side.
Now for the PTFE under the circlip, has anyone measured the distance from the top of the rotor body to the underside of the circlip to determine how much distance
there actually is ?. I will admit it has crossed my mind and yet I did not actually do it myself , so as soon as I can I will take the meter apart again I will attempt to get some
measurement done there and post back, as well as try the knob without the PTFE spacers to see if only the sleeve cured my issue or it is indeed needed to apply light pressure to the rotor.
If even that is actually happening with the spacers installed.
Indeed the fixes we have done for our own are for a bit of tinkering and not 'approved'. And of course I will use the redesigned assembly when it arrives.
But as I have clearly found on my meter the was a direct link to PCB flexure from only small movement of the probe inputs that caused major issues
on the ohm/diode modes of that switch position that it was completely unusable until I did my version of a fix and now in the interim the functions work.
(note that my 121 meters knob was quite 'wobbly' to start with! so I am not convinced its just the knob and not also the rotor slop at play here too.).
Now purely for my own edification I will see what effect the sleeve has without the PTFE packing. Is most surely not going to damage my meter to have a play
while I wait for the 'approved ' replacement part.
I hate to ask, but what is so special about this DMM??? ???There are three stickies and a ton of posts because it's Dave's multimeter, so this is the primary place to discuss it.
One would think by all the posts in now THREE sticky threads that it was the 3rd coming, especially considering these threads are only 3 weeks old. ::)
Who is the manufacture? I don't see it listed in that DMM thread thou that hasn't been updated in 8 months.
Now I have learned. OThere was an announcement thread. There is a Kickstarter page. There is Google.
Of course if there was specific info, other than some U-Boob video as to whom was making/selling this and a link where to buy it, it would of been apparent.
"EEVBlog" doesn't ring a bell as a importer or manufacture. ::)The clues are out there...
Indeed the fixes we have done for our own are for a bit of tinkering and not 'approved'. And of course I will use the redesigned assembly when it arrives.
But as I have clearly found on my meter the was a direct link to PCB flexure from only small movement of the probe inputs that caused major issues
on the ohm/diode modes of that switch position that it was completely unusable until I did my version of a fix and now in the interim the functions work.
(note that my 121 meters knob was quite 'wobbly' to start with! so I am not convinced its just the knob and not also the rotor slop at play here too.).
Now purely for my own edification I will see what effect the sleeve has without the PTFE packing. Is most surely not going to damage my meter to have a play
while I wait for the 'approved ' replacement part.
Gents, all of this is fine for the wobbly knob and rotor action. However it does not address the wear of the knob axis within the PCB. The gunk which was on my PCB tracks (or does it?).
Now purely for my own edification I will see what effect the sleeve has without the PTFE packing.I have removed the packing and left off the circlip too. So testing of the diode mode, (which failed to work on my meter when received), it still works with no issues at all from any probe movement or
I forgot to mention that a couple of days ago I dumped the batteries out of a set top box remote control I need to return and was surprised to see that they were made by UEI. I wonder if the 121GW comes with a UEI battery?
For anyone interested in Dave candidly discussing the 121GW issues:
https://theamphour.com/377-debugger-vs-printeffer/
Spoilers: Dave chuckles over the irony of the slow resistance settling time and what he has said about other meters. He also noted that the slowness was introduced in a late firmware update and he noted that they should have had a formal list of tests to be done for each release.
I'm standing by for the US deliveries....
Can anyone provide info on what UEi have come up with to fix the wobbly switch and intermittent contact issue?When UEi release fully tested fixes and upgrades, Dave will announce it.
For anyone interested in Dave candidly discussing the 121GW issues:
https://theamphour.com/377-debugger-vs-printeffer/
Spoilers: Dave chuckles over the irony of the slow resistance settling time and what he has said about other meters. He also noted that the slowness was introduced in a late firmware update and he noted that they should have had a formal list of tests to be done for each release.
I'm standing by for the US deliveries....
I had a listen to it myself today, as still no word from Dave or UEi on the current state of the meter's repair and updated firmware!
Can anyone provide info on what UEi have come up with to fix the wobbly switch and intermittent contact issue?
For the third or fourth time now, when I know it's all done and dusted, you'll know.If you seriously look at what is involved in the manufacture of an even moderately complex product, this should be no surprise at all.
This stuff doesn't take days to do, it can take weeks.
So I think that's most of the software issues now fixed, but we will not be dribbling out updates every few days and they solve an issue, there will be one big update that includes all the software bug fixes.Getting people to re-flash the firmware 20 times in a month is NOT conducive to a high standard of testing - nor is it an appealing prospect to owners. It is also bad form.
Getting people to re-flash the firmware 20 times in a month is NOT conducive to a high standard of testing - nor is it an appealing prospect to owners. It is also bad form.
While I generally agree with you, I disagree that firmware updates for this meter in its current state should be aggregated for months before being released.Getting people to re-flash the firmware 20 times in a month is NOT conducive to a high standard of testing - nor is it an appealing prospect to owners. It is also bad form.Just look at popular PC forums on motherboards when these tons of whiners cried/cursed/begged etc for frequent BIOS update just for minuscule non critical bug. :palm:
While I generally agree with you, I disagree that firmware updates for this meter in its current state should be aggregated for months before being released.But the manufacturer also has to provide warranty on these meters and they do not want to have to support 100 different versions of updates.
1. The meter is essentially in a beta phase of release right now, so frequent updates and testing will help the manufacturer find and fix issues more quickly. Issues are expected to be the norm at this stage.
This stuff doesn't take days to do, it can take weeks.
While I generally agree with you, I disagree that firmware updates for this meter in its current state should be aggregated for months before being released.
... so frequent updates and testing will help the manufacturer find and fix issues more quickly.Except ... that it won't - necessarily.
https://www.youtube.com/watch?v=uUCQuIp_hzU (https://www.youtube.com/watch?v=uUCQuIp_hzU)
Would you like to see daily posts saying "There is no update today" ?
Bring us along for the ride as it develops, so we can all learn from the experience.
IMO your selling this meter's attributes short by not showing the features off as they are fixed. I say more videos highlighting what goes on technically to rectify the bugs. Don't discount the tremendous interest in this product. Make these early shortcomings its strengths by highlighting the fixes. I would have thought this is a video bloggers dream opportunity!
Those who seem to want to know nothing about the meters progress and are more than happy to wait weeks without an update can just view the thread once a month or so. That way all forum members/backers and supporters of the kickstarter project are all catered for.
Food for thought, Dave?
That's the Dave I know and love watching. I for one enjoy watching the meter development process and it getting tested by you along the way. No need for a media blackout and a code of silence being enforced. We members on these forums are mostly technical people and supporters of yours and appreciate being kept in the loop.
Bring us along for the ride as it develops, so we can all learn from the experience.
That's the Dave I know and love watching. I for one enjoy watching the meter development process and it getting tested by you along the way. No need for a media blackout and a code of silence being enforced. We members on these forums are mostly technical people and supporters of yours and appreciate being kept in the loop.
Bring us along for the ride as it develops, so we can all learn from the experience.
IMO your selling this meter's attributes short by not showing the features off as they are fixed. I say more videos highlighting what goes on technically to rectify the bugs. Don't discount the tremendous interest in this product. Make these early shortcomings its strengths by highlighting the fixes. I would have thought this is a video bloggers dream opportunity!
Those who seem to want to know nothing about the meters progress and are more than happy to wait weeks without an update can just view the thread once a month or so. That way all forum members/backers and supporters of the kickstarter project are all catered for.
Food for thought, Dave?
Kids these days tend to love frequent updates, no matter how shitty the update, as long the manufacturer keep pumping out updates every week, they will be happy, just don't know why. :-//
They have tweaked the dimensions of the white plastic spring assembly and switch assembly I believe.
Kids these days tend to love frequent updates, no matter how shitty the update, as long the manufacturer keep pumping out updates every week, they will be happy, just don't know why. :-//
Talking bullshit with confidence and calling other names doesn't add you credibility. Modern software development is not based on waterfall model anymore.
A good process development process starts with automated tests. But even if you do (semi-)manual testing I don't think it takes much time to test it. Besides that, let the user decide if s/she wants a hotfix that wasn't fully tested.
BTW, I guess you completely missed Dave saying that FW is a mess. I believe this is the main reason it's taking so much time to fix trivial problem, nothing else.
But even if you do (semi-)manual testing I don't think it takes much time to test it.Typical armchair expert. "I don't think" indicates you have no practical knowledge.
Besides that, let the user decide if s/she wants a hotfix that wasn't fully tested.This really shows how out of touch you are with practicality, let alone commercial reality.
https://www.youtube.com/watch?v=uUCQuIp_hzU (https://www.youtube.com/watch?v=uUCQuIp_hzU)
https://www.youtube.com/watch?v=uUCQuIp_hzU (https://www.youtube.com/watch?v=uUCQuIp_hzU)
Thanks for the video Dave, yes the 1.05 FW is noticeably faster than 1.04 and at least as fast as the U1282A. And as expected the Brymen 869 is quite faster but then it also only goes down to 10 milliohms resolution where the 121GW goes down to 1 milliohms.
It would be great if you could do two additional auto-ranging comparisons between 121GW, U1282A and U1272A (and perhaps the Gossen) it would be:
1. AC Volt position, all meters connected in parallel, measuring mains 240volt.
2. DC Amp position, all meters in series, measuring roughly 4.5A DC current load.
This could be good tests to see if any other slowness quirks is lurking in the 121GW FW.
I’m very convinced it’s up to Dave if he wants to make any further auto-raging comparisons. By his own admission - he just didn’t notice how slow the production model was, possibly his focus was on other problems like ie. the bluetooth interface. But if he now feels confident the 121GW really is on par with comparable DMM’s, well then - that’s great!
Five minutes in, I switched to 1080. Your 50K cycles would be a half for Brymen and what I am doing but still, what is up with this meter? There is no way I would have expected to see these results after sending you those original pictures. Impressive indeed.
If these were the production parts, I would like to try and understand why such a dramatic difference. I wouldn't have guessed it had more than a thousand cycles on it but for all I know, UEI may have cycle tested it. Looking back over the pictures, it appears the contacts are what was wearing. Even looking at the last few that they sent, it looks like something was still going on. Strange.Five minutes in, I switched to 1080. Your 50K cycles would be a half for Brymen and what I am doing but still, what is up with this meter? There is no way I would have expected to see these results after sending you those original pictures. Impressive indeed.
I expected worse too, but that's what we got.
I don't know what serial number I sent you, but it would have been around a similar date, so likely exactly the same switch and contacts.
Looking at the video and the large gap in the fingers that rotate the knob, are you sure you are getting the full stroke of the switch? It looks like it may only rotate 90 degrees. Still even it that was the case, I would have still expected that area to have a fair amount of wear.
Just scratching my head.
I agree with Joes counting as this is only a half cycles since a user will turn on, then off and that’s a full cycle. Just like they cling cycles on a battery, charge and discharge for a full cycle.
My questions thinking out loud would be around the way the PLA adapter is mounted to the stepper motor. Seems to me and knowing PLA (it looks like PLA) the part will wear some and if a set screw was used the adapter on the motor will start to slip.
I see your point. But at the same time I think most users will always go for the same “off” position. Maybe based on if they use the meter mostly for current readings, or voltage readings. With mode selected aside I’m still thinking most people will always go to the left off position if they own more then one meter just based on muscle memory and the fact the most other meters they own also go off to the left.
I agree with Joes counting as this is only a half cycles since a user will turn on, then off and that’s a full cycle. Just like they cling cycles on a battery, charge and discharge for a full cycle.
Hmmm, I disagree with your observation in regards to the operation of this meter!
There is an OFF position at each end of the selector, so in effect a user could easily select a range and then switch OFF by continuing in the same direction. Hence one cycle of the switch is achieved by rotating in one direction.
For me personally I will always turn it off to the left because I’m used to turning my meters off to this direction. I do own one meter that has a dual off just like the 121GW (Digitek DT-4000ZC) and it always goes off to the left. Even if I use a mode on the right side of the range switch it still gets turned off to the left. If I had bought a meter that only turned off to the right and didn’t have a left off option, this would probably annoy me to the point of returning it.
Now I need to know if there is or has ever been such a meter?
For me personally I will always turn it off to the left because I’m used to turning my meters off to this direction. I do own one meter that has a dual off just like the 121GW (Digitek DT-4000ZC) and it always goes off to the left. Even if I use a mode on the right side of the range switch it still gets turned off to the left. If I had bought a meter that only turned off to the right and didn’t have a left off option, this would probably annoy me to the point of returning it.Same.
Now I need to know if there is or has ever been such a meter?
For me personally I will always turn it off to the left because I’m used to turning my meters off to this direction. I do own one meter that has a dual off just like the 121GW (Digitek DT-4000ZC) and it always goes off to the left. Even if I use a mode on the right side of the range switch it still gets turned off to the left. If I had bought a meter that only turned off to the right and didn’t have a left off option, this would probably annoy me to the point of returning it.Same.
Now I need to know if there is or has ever been such a meter?
I have not seen that, but some meters has off at the center.Do clamp meters count? Well I have both (left and right), left, top (up), bottom (down), and push button. I can’t find my greenlee meter and I used to have a southwire, but I gave it away. I had to check my old BM235 review video to see what that one was. Now I also wish I never gave away my first RadioShack meter I bought when I was a kid.
Have you checked to make sure you were getting a full cycle with that coupler?
I'm puzzled now that with my 121GW which I use 2-3 times a week for let's say 20-25 cycles I had gunk, abrasion or wear after a couple of weeks already. Perhaps I should clean it now and then take picture and re-take after a month or so. Btw when switching to Ohms range I have to depress the selector switch in order for the meter to switch on otherwise it beeps and then goes dark.Sounds like a good idea to me, take pictures now with cleaned contacts and again later to compare.
I'm puzzled now that with my 121GW which I use 2-3 times a week for let's say 20-25 cycles I had gunk, abrasion or wear after a couple of weeks already. Perhaps I should clean it now and then take picture and re-take after a month or so. Btw when switching to Ohms range I have to depress the selector switch in order for the meter to switch on otherwise it beeps and then goes dark.
Please don't clean it or even take it apart. Just keep using it until you get your replacement parts. Then take some new pictures so we can get some feel for how the wear was progressing, if at all.
Here is a post from left field....is the name of this meter the 121GW, some reference to Back to the Future...as in 1.21 Gigawatts? Just thinking...
Here is a post from left field....is the name of this meter the 121GW, some reference to Back to the Future...as in 1.21 Gigawatts? Just thinking...Yes, be very careful not to take it past 88 mph !
Here is a post from left field....is the name of this meter the 121GW, some reference to Back to the Future...as in 1.21 Gigawatts? Just thinking...
Here is a post from left field....is the name of this meter the 121GW, some reference to Back to the Future...as in 1.21 Gigawatts? Just thinking...
There's no mystery about that. It absolutely is. The naming of this meter was discussed in the Supporters Lounge - two years ago. That's when the name was first put forward .... and Dave jumped at it.
Dave is a BTTF fan boy. (Not sure if I would call him a tragic.)
Maybe I'm showing my age as probably no one on this forum has ever heard of Jimi Hendrix.....
Maybe I'm showing my age as probably no one on this forum has ever heard of Jimi Hendrix.....
Just how old do you think people are here?
I'm sure a lot of us - if not the majority - will have heard of Jimi Hendrix, many will know his music and some will no doubt have been fans.
Heeeeeey Joe...
Ok so theres not much happening with the 121GW! UEi are taking a new years holiday or something?
Lets really go BTTF and I'll provide an insight into what too much time on my hands can do.
I love joeqsmith's meter torture tests, he goes all out and in-depth to provide insights into how accurate and durable a multimeter can be made.
Every time I see a post from Joe I start singing "Hey Joe" in my head but change the words to, "heeeeey joe, where ya gunna go with that meter in your hand, where ya gunna go". Maybe I'm showing my age as probably no one on this forum has ever heard of Jimi Hendrix or his band the Jimi Hendrix Experience.
Jimi was also famous for another song, Purple Haze, and it seems to me a direct connection with joeqsmith. Its obvious why, when Joe hits a meter with his HV spike test the meter explodes into a purple plasma haze.
Its a slow afternoon for me, so just thought I'd share a BTTF memory moment that the 121GW triggered.
Lets hope that UEi and Dave have some good news for us soon on how this meter is coming along!
When the production unit finally ships, I'm really looking forward to it being given the JoeQSmith Experience and singing along while I watch him destroy it, just like Jimi used to do to his guitars :D
Sorry. As much as I might like an update - there's little point in pushing.
If anything, I'd rather effort be put into addressing the issues than taking time out to give progress reports. Reporting is one way to waste time - and pressing for it, when it isn't going to change the timetable, is somewhat counterproductive.
Gentlemen, as much fun and smiles this all gives it does digress from the topic for me. I would really like to see things from Dave: 1. an overall issue list of all the hardware and software related issues, 2. an update, with tentative dates, on when which issue will be addressed (e.g. I could imagine all to be resolved or some to drop and then re-certification is needed?). 3. how to continue with new issues people will start to find (like say the range-switch PCB tracks wearing down or gunk build-up or .... ). Agree?
2. an update, with tentative dates, on when which issue will be addressed
It has been found that the switch contact issues were ultimately caused by a slight PCB thickness difference between the pre-production and production boards.Does "the low side" mean that the board is too thin? Is the 0.95mm shim meant to be attached to the circuit board? Just confused a bit.
Pre-production boards were on the high side of the tolerance allowance, and production boards on the low side. Actually, the production board thickness was actually slightly outside of UEi's board spec.
A 0.95mm shim (as has been found by others) is the fix for existing units and current stock boards (i.e. all Kickstarter ones and for sometime afterwards). Future volume production boards shouldn't need a shim however.
Shims are on the way to me now for cycle testing.
It has been found that the switch contact issues were ultimately caused by a slight PCB thickness difference between the pre-production and production boards.Does "the low side" mean that the board is too thin? Is the 0.95mm shim meant to be attached to the circuit board? Just confused a bit.
Pre-production boards were on the high side of the tolerance allowance, and production boards on the low side. Actually, the production board thickness was actually slightly outside of UEi's board spec.
A 0.95mm shim (as has been found by others) is the fix for existing units and current stock boards (i.e. all Kickstarter ones and for sometime afterwards). Future volume production boards shouldn't need a shim however.
Shims are on the way to me now for cycle testing.
So that means that the fact the board is too thin is not being addressed unless the shim is causing the shaft clip to press down on the switch rotor. It just seems to me that if the board it too thin, there should be a shim under the rotor clip.Does "the low side" mean that the board is too thin? Is the 0.95mm shim meant to be attached to the circuit board? Just confused a bit.
Yes, on the thin side.
The shim goes between the plastic range switch and the case, as per how others have done their own DIY solution.
For those that want to do it themselves, the shim thickness is 0.95mm.
So that means that the fact the board is too thin is not being addressed unless the shim is causing the shaft clip to press down on the switch rotor. It just seems to me that if the board it too thin, there should be a shim under the rotor clip.Does "the low side" mean that the board is too thin? Is the 0.95mm shim meant to be attached to the circuit board? Just confused a bit.
Yes, on the thin side.
The shim goes between the plastic range switch and the case, as per how others have done their own DIY solution.
For those that want to do it themselves, the shim thickness is 0.95mm.
Like this picture from forum member lowimpedance previous post?I think that is the fix Dave is talking about. I am just asking if there should be a shim on the plastic clip on the actual switch rotor on the PCB and not just one on the shaft.
Like this picture from forum member lowimpedance previous post?I think that is the fix Dave is talking about. I am just asking if there should be a shim on the plastic clip on the actual switch rotor on the PCB and not just one on the shaft.
That shim in the photo is certain a way to reduce the wobble in the switch knob which is a second problem.
Like this picture from forum member lowimpedance previous post?I think that is the fix Dave is talking about. I am just asking if there should be a shim on the plastic clip on the actual switch rotor on the PCB and not just one on the shaft.
That shim in the photo is certain a way to reduce the wobble in the switch knob which is a second problem.
Agree with you. I think the range switch, the plastic knob, could be redesgined a bit so that a wobble is less likely to occur. Let's wait for final testing by Dave and team for a prolonged period 50.000 cycles or more if this is the solution. Nonetheless happy to read that a difference and potential root cause has been identified.
Can someone please measure the input impedance when the mVDC is selected.It is about 9.9M.
Any plans regarding sigrok support for this meter?
If you go back now and look, it appears the data was removed. I watched it after it was live and assume it would have had to been cut and reloaded.
Strange as I don't remember it being anything that I considered that out of the ordinary. They were messing with the jig a fair amount and maybe just want to show a clean data set. It sounded like they may run a few other meters as well.
That's odd. I know I saw the plots the first time I watched the videos. Maybe I am just not able to find it.
I really have not seen a lot of testing going of of these first meters, not like I had hoped for anyway. It's premature to think about it.
Going to have a giveaway for the highest use 121GW in existence?
UPDATE: We completely screwed the pooch! We installed the shim upside down!Why have they routed the recess then? It isn't meant to fit between the case and the clip, is it? Otherwise it seems they have thinned the part of the spacer taking all the force.
There was supposed to be no contact friction between the shim and the plastic case (which created all the dust). Apparently we were too dumb to read UEI's instructions precisely. Doh.? :palm:
Why have they routed the recess then?That's the question that came to my mind as well.
UPDATE: We completely screwed the pooch! We installed the shim upside down!Why have they routed the recess then? It isn't meant to fit between the case and the clip, is it? Otherwise it seems they have thinned the part of the spacer taking all the force.
There was supposed to be no contact friction between the shim and the plastic case (which created all the dust). Apparently we were too dumb to read UEI's instructions precisely. Doh.? :palm:
The recess fits over the protruded tab on the actual top of the range switch, I showed this on the latest live feed.
The circlip actually resides flush with the case as it's in a concave part of the case molding.
The recess fits over the protruded tab on the actual top of the range switch, I showed this on the latest live feed.
The circlip actually resides flush with the case as it's in a concave part of the case molding.
How about a link Dave!
I couldn't find the live feed where you show the correct position of the spacer.
If you want to compare it with the Fluke 17B+, SC4. I have no answer why this meter is so stable. The contacts are a whole different setup.I wonder if the resistance connections going through the switch are 4 wire in the Fluke. It is one possible explanation for the dramatic improvement in performance over all the other meters.
Also, just remember those who did get the meters, got them at a reduced price. That came with a risk, one that was pretty much expected by many. When I'm able to get one of these for myself, I will be paying more in dollar terms, but less in time.Well I dunno about that Brumby! I think you have invested plenty of time on this thread already :D
Your comments are plentiful and you usually dont spare us the depth of your insights into how this meter should or shouldn't be developed and what should or shouldn't take place before its released as a production unit.Sorry.
Dave, I mentioned I had uploaded a few clips of Brymen's test jig in operation. The attached link shows starts at those clips. It is followed by showing how my setup works.
https://youtu.be/bs5n3a__Yq0?t=400
Dave, I mentioned I had uploaded a few clips of Brymen's test jig in operation. The attached link shows starts at those clips. It is followed by showing how my setup works.
https://youtu.be/bs5n3a__Yq0?t=400
Joe, watching the video of your test jig in action, it becomes apparent just how brutal Dave's jig is compared to yours. Your switch actuating "fingers" and timed sequencing approximates real world usage. At least it appears that way to me.
It suggests to me that Dave's jig would inflict more wear and damage than may be found in other manufacturers testing of their meter's switches?
It also shows the relevance of having someone like you running uniform consistent tests on a range of meters and brands so that a true indication of robustness, precision and accuracy can be conveyed to the prospective buyer.
Definitely looking forward to seeing how the blue meter performs once you get hold of a "production" unit.
Watching the video also presented me with the same dilemma that confronted Neo. Choose the Red meter or the Blue meter, as I considered the Brymen a worthy competitor for my money!
Now about those yellow sticky notes. I saw they were no longer shown in the edited video so I have attached a screen shot. Granted, I am not sure why they use r=V/3300 only to invert it below but the numbers don't seem to work out even close to what their meter was reading and everything is well above the 10 ohm limit. Is this that new math I keep hearing about?
UPDATE:
Software
- Windows app software is now available on the Microsoft store.
I have downloaded the software onto my Windows 10 laptop. I am waiting for my meter but I thought I would have a quick poke around the software beforehand. I would have though that it would be similar to the Android version that actually has a display but no such luck. All I get when I start the software is a window with <Settings> and a refresh button at the bottom of the screen. Clicking on <> or Settings does nothing.
F/w 1.07: the Sound of Silence :-+I was going to post earlier but hit a stumbling block.
F/w 1.07: the Sound of Silence :-+I was going to post earlier but hit a stumbling block.
After loading 1.07, I found my current ranges no longer work. Put it back to 1.01 and they still do not work - reads overflow on many ranges. I am debugging the meter to see if I just got a switch problem at the same time as the upgrade. The meter has not been near high voltages and currents and the fuses and shunts are fine. The current ranges did work perfectly. It is not a lost calibration issue - it looks more like a floating connection that should be going to the shunt resistors.
The resistance now goes from open to a short in under 5 seconds - much more respectable. :-+
Looks like VA is still restricted to 55V maximum and they haven't fixed the issues with the capacitance manual range yet:
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/150/ (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/150/)
After loading 1.07, I found my current ranges no longer work. Put it back to 1.01 and they still do not work - reads overflow on many ranges. I am debugging the meter to see if I just got a switch problem at the same time as the upgrade. The meter has not been near high voltages and currents and the fuses and shunts are fine. The current ranges did work perfectly. It is not a lost calibration issue - it looks more like a floating connection that should be going to the shunt resistors.
1520424876.136 2017-08 00042 Power DC (VA) 0.0 mVA DCA 0.01
1520424876.406 2017-08 00042 Power DC (VA) 0.0 mVA DCA 0.01
1520424876.676 read STDIN: invalid byte: 6 of 34
1520424876.676 read STDIN: invalid byte: 13 of 20
1520424876.676 read STDIN: invalid byte: 10 of 19
1520424876.811 read STDIN: invalid byte: 10 of 14
1520424877.081 2017-08 00042 Power DC (VA) 0.3 mVA DCA 0.01
1520424877.352 2017-08 00042 Power DC (VA) 0.3 mVA DCA 0.01
1520424877.621 read STDIN: invalid byte: 131 of 34
1520424877.621 read STDIN: invalid byte: 10 of 33
1520424877.756 read STDIN: invalid byte: 10 of 14
1520424878.026 2017-08 00042 Power DC (VA) 0.0 mVA DCA 0.01
1520424878.296 2017-08 00042 Power DC (VA) 0.0 mVA DCV 0.0000
1520424878.566 2017-08 00042 Power DC (VA) 0.0 mVA DCV 0.0000
1520424878.836 2017-08 00042 Power DC (VA) 0.1 mVA DCV 0.0000
1520424879.106 2017-08 00042 Power DC (VA) 0.1 mVA DCV 0.0000
1520424879.376 2017-08 00042 Power DC (VA) 0.1 mVA Low_Z 4112
1520424879.646 read STDIN: invalid byte: 10 of 34
1520424879.781 2017-08 00042 Power DC (VA) 0.0 mVA DCV 0.0000
1520424880.051 2017-08 00042 Power DC (VA) -0.4 mVA DCV 0.0000
1520424880.321 2017-08 00042 Power DC (VA) -0.4 mVA DCV 0.0000
1520424880.591 2017-08 00042 Power DC (VA) 0.0 mVA DCV 0.0000
1520424880.861 2017-08 00042 Power DC (VA) 0.0 mVA DCV 0.0000
1520424881.131 read STDIN: invalid byte: 24 of 34
1520424881.131 read STDIN: invalid byte: 13 of 19
1520424881.131 read STDIN: invalid byte: 10 of 18
1520424881.266 read STDIN: invalid byte: 20 of 14
1520424881.266 read STDIN: invalid byte: 10 of 13
1520424881.536 read STDIN: invalid byte: 10 of 14
1520424881.806 2017-08 00042 Power DC (VA) 0.0 mVA DCA 0.01
1520424882.076 2017-08 00042 Power DC (VA) 0.0 mVA DCA 0.01
- Existing backers with meters will get shipped a replacement switch and shim and instructions.Thank you I am eagerly waiting for this fix!
FirmwareThank you for the new firmware, works fine for me and auto range is really ok now even if it is not the fastest (for me max. 4 - 5 secs).
- We will now release version 1.07 it can be downloaded here:
That's what I figured, but my initial look at the circuit showed a lot of the current switching is done by cmos switches. Both the buffered and unbuffered ranges are affected. The rotary switch seems to be perfect. I cannot find any obvious continuity faults right now. I will hook up some power and test the voltages tomorrow. It might be a broken track or a dry joint.After loading 1.07, I found my current ranges no longer work. Put it back to 1.01 and they still do not work - reads overflow on many ranges. I am debugging the meter to see if I just got a switch problem at the same time as the upgrade. The meter has not been near high voltages and currents and the fuses and shunts are fine. The current ranges did work perfectly. It is not a lost calibration issue - it looks more like a floating connection that should be going to the shunt resistors.
I would presume that has to a coincidental intermittent switch issue. No other reason would make sense.
1520427022.717 2017-08 00042 Power DC (VA) 2499.9 mVA DCV 1.5652
1520427022.987 2017-08 00042 Power DC (VA) 2499.8 mVA DCV 1.5652
1520427023.257 2017-08 00042 Power DC (VA) 2499.8 mVA DCV 1.5652
1520427023.527 2017-08 00042 Power DC (VA) 2499.8 mVA DCV 1.5652
1520427023.797 2017-08 00042 Power DC (VA) 391.2 mVA DCV 1.5652
1520427024.067 2017-08 00042 Power DC (VA) 391.2 mVA DCV 1.5652
1520427024.742 2017-08 00042 Power DC (VA) 1564.9 mVA DCA 249.97
1520427025.282 2017-08 00042 Power DC (VA) 1565.2 mVA DCA 249.97
1520427025.552 2017-08 00042 Power DC (VA) 391.2 mVA DCA 249.97
1520427025.822 2017-08 00042 Power DC (VA) 2500.0 mVA DCA 249.97
1520427026.565 2017-08 00042 Power DC (VA) 2499.9 mVA DCA 249.97
1520427027.240 2017-08 00042 Power DC (VA) 391.3 mVA DCA 249.99
1520427027.510 2017-08 00042 Power DC (VA) 391.3 mVA DCA 249.99
1520427027.780 2017-08 00042 Power DC (VA) 1521.7 mVA DCV 1.5653
1520427028.050 2017-08 00042 Power DC (VA) 1565.2 mVA DCV 1.5653
1520427028.320 2017-08 00042 Power DC (VA) 1565.2 mVA DCV 1.5653
1520427029.265 2017-08 00042 Power DC (VA) 2500.2 mVA DCV 1.5655
1520427029.535 2017-08 00042 Power DC (VA) 2500.0 mVA DCV 1.5655
1520427029.805 2017-08 00042 Power DC (VA) 2500.1 mVA DCV 1.5655
1520427030.075 2017-08 00042 Power DC (VA) 2500.0 mVA DCV 1.5655
1520427030.345 2017-08 00042 Power DC (VA) 2500.1 mVA DCV 1.5655
1520427031.020 2017-08 00042 Power DC (VA) 1516.9 mVA DCV 1.5655
1520427031.290 2017-08 00042 Power DC (VA) 1516.9 mVA DCA 250.00
The 24 hour video was no longer listed when I checked, so yes I was referring to your how-to video.
@Dave: at the risk of sounding like an ungrateful asshole, while the beeper on/off option is fantastic (nice and quite now! :-+ ), it renders the continuity beeper also silent, which I would argue either should have it's own configuration option, or at least be on all the time, even if the beeper for functions/buttons is turned off.
That being said, I don't know that I would classify this as an "issue". A big thanks to UEi for getting issues in the FW addressed quickly!
Bluetooth and VA mode is still completely broken, even if you filter the invalid records.
It's also broken in the android app. It displays the same wrong readings.
The 391.2 mVA reading is the correct one.
I personally think the beeper is necessary in the following circumstances:
- Continuity (which even uses the sound symbol!)
- Diode test
- When you've been an idiot and left a probe in the A jack when the meter is in voltage mode (assuming it's using sensing jacks - can't remember if this is the case)
- Over-load warning on ranges where an overload could cause damage
Other than those, I'd normally want the beeper off, so I'd agree with everyone asking for a middle option (preferably as a third setting in addition to the current two)
a) Nothing was "removed in editing". The entire original 23 hour video is still being processed by youtube and will eventually be available online. It seems that only the final 2 hours is currently available.
b) By the "edited video" I presume you mean the one "How to do Lifecycle Testing". I simply extracted some content from the stream to create a new video were I talked about general range switch testing as I thought it might be interesting to people as separate video.
c) There is a uCurrent x100 amplifier used in the jig across the switch contacts, that is not shown in the equations.
The 24 hour video was no longer listed when I checked, so yes I was referring to your how-to video.Quote.. r=v/2300 and R=2740/((1/r)-1) . The second note stated the first column was V. So for v=128, R=2740/((2300/128)-1) = 152.5.
I assume it's not as simple as it being off by 100X or 0.152 ohms, seems way too low but maybe. Looking at V=1272, R = 1.516 in this case and I think it was much higher. Strange that the basics are not clear or just coded.
Maybe someone can explain to me what the problem is:
2 different function generators tested, JDS6600 and FeelTech FY6600. Identical settings, identical results.
For example: 4kHz SQRT with 2Vpp. Measured ACV with the 121GW and as comparison a Fluke 28II (highres mode).
Range AUTO: 121GW selects 5V range, Fluke selects 6V range
121GW reads 1,37xxVac, Fluke reads 0,99xxVac
Manual range 5V 121GW, 6V Fluke 28II:
121GW reads 1,37xxVac, Fluke reads 0,99xxVac
Manual range 50V 121GW, 60V Fluke 28II:
121GW reads 0,95xVac, Fluke reads 0,94xxVac
I uploaded video regarding roughly comparing Burden Voltage.QuoteOn your 121GW, you do have a fairly high resolution. In the Amps low range, I think its 10uA resolution which is what you have with the other meters. However, your burden voltage is to be VERY low. Maybe 200ish uv!! Try that and see what you think.?
I posted the above comment on YT. Looking in the manual, maybe it no longer works this but I'm pretty sure that the prototype did.
Thanks.I uploaded video regarding roughly comparing Burden Voltage.QuoteOn your 121GW, you do have a fairly high resolution. In the Amps low range, I think its 10uA resolution which is what you have with the other meters. However, your burden voltage is to be VERY low. Maybe 200ish uv!! Try that and see what you think.?
I posted the above comment on YT. Looking in the manual, maybe it no longer works this but I'm pretty sure that the prototype did.
The 500mA range uses the Amps jack (and a x10 amplifier) unlike most meters. This gives a very low maximum burden voltage of 30mV/A, or 15mV for 500mA full scale.
Very few meters will be this low on the 500mA range.
With 50,000 count the resolution is 10uA.
I had DL'ed the manual when you made it available. The one I have is 25th Nov. 17. I see a mention of the 500mA mode on page 11.QuoteA and 500mA 11A/1000V DC/AC, IR 20kA HRC FAST + DIODEand again on page 55QuoteA/500mA current input fuse: 11A/1000V DC/AC, IR 20kA HRC FAST
The table on page 14 does not mention it.QuoteThe following modes will use the x10 amplifier and may have additional off-set error that can be nulled out before measurement.
Maybe add something to page 32 where the current measurement is shown. When I looked at the burden on the pre-production, is was pretty impressive. From fanOfeeDIY's video, the manual may need a few small additions.
Maybe you (Dave) would consider making a short video showing the meter's burden compared to a few others and how to use it properly.
I am not quite following the discussion. [emoji22]
Especially "200ish uv!!" part.
Should I have used different range in my video?
Do the same test with your 121GW except attach the leads from the A 500mA connector and the COM. The 121GW will display the current with a resolution of 10uA just like the others you show. However, now if you look at the burden voltage for the meter, I suspect you will see something around 200uV rather then several mV as your video shows. I use "ish" as close enough.
I had modified a UNI-T UT61E which has a very high burden voltage, in an attempt to improve it. There was only so much I could do in the area available and the way the board was laid out. I think are real low current, the burden on this meter was lower than the 121GW but once I changed ranged, it was very clear just how good the 121GW was. It's impressive. Give it a try and see what happens. Post your updates, text is good enough.
I am not quite following the discussion. :'(
Especially "200ish uv!!" part.
Should I have used different range in my video?
Do the same test with your 121GW except attach the leads from the A 500mA connector and the COM. The 121GW will display the current with a resolution of 10uA just like the others you show. However, now if you look at the burden voltage for the meter, I suspect you will see something around 200uV rather then several mV as your video shows. I use "ish" as close enough.
I had modified a UNI-T UT61E which has a very high burden voltage, in an attempt to improve it. There was only so much I could do in the area available and the way the board was laid out. I think are real low current, the burden on this meter was lower than the 121GW but once I changed ranged, it was very clear just how good the 121GW was. It's impressive. Give it a try and see what happens. Post your updates, text is good enough.
Maybe add something to page 32 where the current measurement is shown. When I looked at the burden on the pre-production, is was pretty impressive. From fanOfeeDIY's video, the manual may need a few small additions.
Thank you for your valuable comment on both YouTube and here.Thank you for taking the time to run the test a second time.
I uploaded another video.
I am not quite following the discussion. :'(
Especially "200ish uv!!" part.
Should I have used different range in my video?
Do the same test with your 121GW except attach the leads from the A 500mA connector and the COM. The 121GW will display the current with a resolution of 10uA just like the others you show. However, now if you look at the burden voltage for the meter, I suspect you will see something around 200uV rather then several mV as your video shows. I use "ish" as close enough.
I had modified a UNI-T UT61E which has a very high burden voltage, in an attempt to improve it. There was only so much I could do in the area available and the way the board was laid out. I think are real low current, the burden on this meter was lower than the 121GW but once I changed ranged, it was very clear just how good the 121GW was. It's impressive. Give it a try and see what happens. Post your updates, text is good enough.
Thank you for your valuable comment on both YouTube and here.
I uploaded another video.
https://youtu.be/ffP1Y0zp9KE
V1.09 firmware https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip (https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip)
It fixes the issue with the VA mode Bluetooth connection sending garbage data.
I'm sure they run some sort of regression testing before they release updates and that is partly why UEI's response is slow.
Then again, now that Dave has stepped into the role of running life cycle testing maybe he needs to expand into some sort of firmware quality role as well.
gatttool -b 88:6B:XX:XX:XX:XX --char-write-req -a 0x0009 -n 0300 --listen | ./121gw.pl
gatttool -b 88:6B:XX:XX:XX:XX --char-write-req -a 0x0009 -n 0300 --listen | ./121gw.pl 2>&1 | tee logfile.txt
hcitool lescan
and press ctrl-C when it is found.V1.09 firmware https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip (https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip)
It fixes the issue with the VA mode Bluetooth connection sending garbage data.
Not really, the main display is correct now, but the upper display lost any connection to reality.
The corrupted data records are still there but less frequent.
:palm:
It seems 1.09 was a regression of other functionality in the VA mode.
The link has been removed.
V1.09 firmware https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip (https://www.eevblog.com/wp-content/uploads/2017/11/EEVBlog1_09.zip)
It fixes the issue with the VA mode Bluetooth connection sending garbage data.
Not really, the main display is correct now, but the upper display lost any connection to reality.
The corrupted data records are still there but less frequent.
:palm:
Can you confirm your setup was in DC mode? What were the conditions which resulted in the incorrect values of the secondary display on the 121GW?
Old post about this was removed as it seems it was not a regression and instead a different error.
Can you confirm your setup was in DC mode? What were the conditions which resulted in the incorrect values of the secondary display on the 121GW?
Old post about this was removed as it seems it was not a regression and instead a different error.
I used DC mode, 400mA, 3.7V, 1.42VA. Both displays on the meter itself are perfect.
The display via bluetooth on the secondary display is 2.9V and 255.86A, the main display is fine.
Are you on windows or Android, which version of the app?
Are you on windows or Android, which version of the app?
I tried Android Version 0 eevblog.x121gw, but my perl script displays the same values.
It doesn't matter, fix the BT transmission with a correct buffering implementation.
I understand the Perl script might be receiving the wrong thing too. Just to be thorough can you check if the updated android app resolves your issue.
Curiously the android app store might not have received the latest updates... Checking into this now... Ok it should be version 1 now :)
1521202937.913 2017-08 00042 Power DC (VA) 1409.7 mVA DCA 255.34
1521202938.183 2017-08 00042 Power DC (VA) 140.97 VA DCA 255.34
1521202938.858 2017-08 00042 Power DC (VA) 1409.7 mVA DCA 255.34
What process is UEi and Dave following for firmware releases?
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.
Would current owner prefer we not make interim firmware releases available for testing?
What process is UEi and Dave following for firmware releases?At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback. Would current owner prefer we not make interim firmware releases available for testing?
My concern was that in your previous post you stated that the new firmware release fixed the BT data corruption issues. You maybe could have said please test this new release which addresses the BT data corruption issue and provide feedback if any issue remains.
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.This is understandable - and very effective - but there will be some who will get their nose out of joint because everything isn't perfect ... including the software revisions. To those I say this: When a car maker designs and builds a new car, they don't just dump the first models straight from the factory to the showroom. It goes through a proving ground where issues are identified and dealt with. For the 121GW - we are that proving ground and we are still in the stage of finding and fixing issues.
From our end it did look like the data corruption UART issue we reported had been fixed, and that seems to be the case.This is a good example where different problems can have similar looking symptoms - and that the fixing of one problem may not result in a total cure. For a complete solution, each and every problem needs to be individually identified and addressed. Where it is stated that one particular problem has been fixed, don't immediately assume the symptoms you have observed should go away and that if they don't, that you are being misled.
I know some people are still reporting bluetooth data corruption issues, and this seems to be a different issue than the one we had UEi adress, which was corrupted data output from the UART in the micro.
Please take every release at this stage to mean "we believe it's fixed, please test it and let us know if you find any issues".This.
It was not clear to me that people purchasing the meter were expected to be Beta tester's until I had heard Dave mention it during an AmpHour. I'm sure he must have stated this upfront and I just missed it. As long as it was made clear, I don't see a problem. On the other hand, if it wasn't and people were trusting that Dave would not allow it to be sold as a Beta, then maybe that's a problem. Seems like most in the USA are still waiting, so no concerns other than not meeting their scheduled dates.At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.This is understandable - and very effective - but there will be some who will get their nose out of joint because everything isn't perfect ... including the software revisions. To those I say this: When a car maker designs and builds a new car, they don't just dump the first models straight from the factory to the showroom. It goes through a proving ground where issues are identified and dealt with. For the 121GW - we are that proving ground and we are still in the stage of finding and fixing issues.
I am not sure why he chose to use the open forums for discussions and bug reporting versus the locked down kick start area. Maybe he has more control over the content here.
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.This is understandable - and very effective - but there will be some who will get their nose out of joint because everything isn't perfect ... including the software revisions. To those I say this: When a car maker designs and builds a new car, they don't just dump the first models straight from the factory to the showroom. It goes through a proving ground where issues are identified and dealt with. For the 121GW - we are that proving ground and we are still in the stage of finding and fixing issues.
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.This is understandable - and very effective - but there will be some who will get their nose out of joint because everything isn't perfect ... including the software revisions. To those I say this: When a car maker designs and builds a new car, they don't just dump the first models straight from the factory to the showroom. It goes through a proving ground where issues are identified and dealt with. For the 121GW - we are that proving ground and we are still in the stage of finding and fixing issues.
We didn't want that to be the case of course, but we've been essentially forced into this situation with the unexpected problems that have popped up.
And by "forced into" I mean it's basically the best way forward at this point for all involved.
The best way to get issues found is by having as many people as possible use the meter and provide feedback as possible. Given that we have like 200 or something meters out there in the field now, it just makes sense to at least ask these owners to try new firmware and continue to provide feedback before we ship 2000 of them. They don't have to of course, they can stick with the firmware they have got.
But ultimately any new firmware on a reasonably complex product like this is going to have issues that will take time to sort out.
BTW, David in his testing has found a couple of more unreported issues that are currently being looked into, hence more delays unfortunately.
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.This is understandable - and very effective - but there will be some who will get their nose out of joint because everything isn't perfect ... including the software revisions. To those I say this: When a car maker designs and builds a new car, they don't just dump the first models straight from the factory to the showroom. It goes through a proving ground where issues are identified and dealt with. For the 121GW - we are that proving ground and we are still in the stage of finding and fixing issues.
We didn't want that to be the case of course, but we've been essentially forced into this situation with the unexpected problems that have popped up.
And by "forced into" I mean it's basically the best way forward at this point for all involved.
A one sentence summary would be that the 121GW meter was a good idea poorly implemented!I understand where you are coming from, but I would call that a bit harsh. I would call that a "consumer" comment, not an "engineer" one.
Hindsight is a wonderful thing, but maybe if Dave ponied up and backed his own idea and design instead of a freebie UEi deal, it may have actually been developed and tested before being released to backers to buy?There are a lot of factors in producing any item and I sincerely doubt Dave would have been able to bring this product to life without UEI's contribution. Certainly, there has been an issue with the testing and that is the only criticism I have - but Dave probably didn't do himself any favours by having the development so highly visible. The interest and yearning from so many members no doubt added a lot of pressure to get the product out.
The potential for getting a useful meter, (I'm Johnny Be Goode backer) is still high, but the way it has been handled with bugs and switch problems has certainly knocked the gloss of acquiring this meter for me!I am quite the opposite. Having seen the effort being put in, I am becoming more engaged. The gloss is increasing!
I will say that if the 121GW had hit the deck with no significant issues, I would have been truly impressed - but the number of issues detailed so far has been a bit of a surprise. What I expected to be a bit of "fine tuning" has turned into a significant exercise. I think Dave would have had a similar expectation.
As far as the 121GW is concerned, I bet the hardware has far fewer issues than the software. It's because software design is not recognized as challenging problem requiring deep expertise, and software then gets written by "coders" instead of engineers. The word "coding" should be removed from the dictionary.
Dave probably didn't do himself any favours by having the development so highly visible.
Those 2000 get the updated hardware (switch..) right?
[\quote]
Yes.QuoteWhat about the meters stuck at the harbor, are these unstuck yet?
Yep, all finally unstuck.QuoteWhat about selling these to "qualified" (those that are aware of what they are getting themselves into) beta testers?
I'd rather not, we already have enough keen people out there testing I think.
Dave probably didn't do himself any favours by having the development so highly visible.
Yep, I'm not very smart :palm:
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.
This is fine, but please "fix" things and don't "cover up".
The bluetooth transmission is broken by design and by implementation.
- There is no data integrity, aka. CRC or something on records (design error)
- The ASCII decimal/hex coding wastes more then 2/3 of the already scarce bluetooth bandwidth (design error)
- You have to check every single byte received for plausibility (and you'll fail in a lot of cases) (implementation error)
- If you look at the errors in the data it's clear that some buffer in the firmware get's overwritten (implementation error)
Would current owner prefer we not make interim firmware releases available for testing?
I'm fine with testing, no problem.
But the 1.07 -> 1.09 is not a fix, it's just trying to cover up above mentioned errors a bit better.
Start with fixing the missing CRC. Then errors can be detected reliably and automatically and one can trust the data received is what the firmware wanted to send.
measuring in 1 m distance:
number of packets: 348697
transfer time: 255 s
lost packets: 0
average transfer rate: 27310 bytes per second
max delay between two packets: 79.6 ms
min delay between two packets: 0.0 ms
measuring in 7m distance, with 2 walls in between:
number of packets: 265549
transfer time: 331 s
lost packets: 0
average transfer rate: 16044 bytes per second
max delay between two packets: 284.1 ms
min delay between two packets: 0.0 ms
Bus 001 Device 012: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
import struct
from bluepy.btle import *
# callback class
class MyDelegate(DefaultDelegate):
def __init__(self):
DefaultDelegate.__init__(self)
def handleNotification(self, cHandle, data):
print(data)
# connect to device
per = Peripheral("00:0B:57:1D:B3:93", "public")
try:
# set callback for notifications
per.setDelegate(MyDelegate())
# enable notification
setup_data = b"\x01\x00"
notify = per.getCharacteristics(uuid='6e400003-b5a3-f393-e0a9-e50e24dcca9e')[0]
notify_handle = notify.getHandle() + 1
per.writeCharacteristic(notify_handle, setup_data, withResponse=True)
# send test string
c = per.getCharacteristics(uuid='6e400002-b5a3-f393-e0a9-e50e24dcca9e')[0]
c.write("Hello Gecko")
# wait for answer
while True:
if per.waitForNotifications(1.0):
continue
finally:
per.disconnect()
#!/usr/bin/python
import sys
filename = sys.argv[1]
# statistic variables
count = 0
lastPacketNumber = 0
lastTimestamp = 0
deltaSum = 0
maxDelta = 0
minDelta = 1e9
packetsLost = 0
absoluteTimestamp = 0
# read file and calculate statistics
with open(filename, "r") as ins:
for line in ins:
values = line.split(";")
packetNumber = int(values[0])
timestamp = int(values[1])
delta = timestamp - lastTimestamp
if count > 0:
if timestamp < lastTimestamp:
delta = 32768 - lastTimestamp + timestamp
if delta > maxDelta:
maxDelta = delta
if delta < minDelta:
minDelta = delta
absoluteTimestamp = absoluteTimestamp + delta
if packetNumber - lastPacketNumber > 1:
packetsLost = packetsLost + packetNumber - lastPacketNumber - 1
lastPacketNumber = packetNumber
lastTimestamp = timestamp
count = count + 1
# format milliseconds with suffix and one digit after the comma
def formatMs(ms):
return "{:.1f} ms".format(ms)
# convert ticks to seconds
def ticksToS(tick):
return float(tick) / 32768.0
# convert ticks to miliiseconds
def ticksToMs(tick):
return ticksToS(tick) * 1000.0
# calculate some more statistics
transferTimeInSeconds = ticksToS(absoluteTimestamp)
bytesTransfered = count * 20
bytesPerSecond = float(bytesTransfered) / transferTimeInSeconds
# show result
print("number of packets: %d" % (count))
print("transfer time: %d s" % (int(transferTimeInSeconds)))
print("lost packets: %d" % (packetsLost))
print("average transfer rate: %d bytes per second" % (int(bytesPerSecond)))
print("max delay between two packets: " + formatMs(ticksToMs(maxDelta)))
print("min delay between two packets: " + formatMs(ticksToMs(minDelta)))
No need to implement CRC, because BLE has this already integrated on the lower levels and automatically resends packets, if they are wrong, so no need to implement it on the data layer. Usually you can be sure that the transmitted data is right, so it must be another problem.
No need to implement CRC, because BLE has this already integrated on the lower levels and automatically resends packets, if they are wrong, so no need to implement it on the data layer. Usually you can be sure that the transmitted data is right, so it must be another problem.
Yes I know. I checked the BLE spec.
The problem is with the firmware communicating with the BLE-module and the guesswork seems to be in the App since last August. So they seem to know since some time.
Ok, but why did you write that the protocol is broken without some sort of data integrity like CRC? Even industry standard protocols like SCPI (which would be nice to have in the multimeter) don't have integrated checksums, but it is implemented in the lower levels as TCP/IP (don't know if GPIB has a checksum).
Since the serial communication between the BLE module and the CPU is not protected and obviously unreliable.
I guess it's hard to impossible to add protection to the BLE-module, so just make it end-to-end.
It's cheap and easy and you're set.
A one sentence summary would be that the 121GW meter was a good idea poorly implemented!I understand where you are coming from, but I would call that a bit harsh. I would call that a "consumer" comment, not an "engineer" one.
This would be a bad patch, and if it is a problem in the firmware before the checksum is calculated, it wouldn't even help.
But Dave wrote that one data corruption UART issue was fixed. Would be better to find all issues instead of trying to program workarounds.
No need to implement CRC, because BLE has this already integrated on the lower levels and automatically resends packets, if they are wrong, so no need to implement it on the data layer. Usually you can be sure that the transmitted data is right, so it must be another problem.
Yes I know. I checked the BLE spec.
The problem is with the firmware communicating with the BLE-module and the guesswork seems to be in the App since last August. So they seem to know since some time.
It would be useful if the user could receive some feedback regarding incomplete / lost packets in the app.No need to implement CRC, because BLE has this already integrated on the lower levels and automatically resends packets, if they are wrong, so no need to implement it on the data layer. Usually you can be sure that the transmitted data is right, so it must be another problem.
Yes I know. I checked the BLE spec.
The problem is with the firmware communicating with the BLE-module and the guesswork seems to be in the App since last August. So they seem to know since some time.
The firmware and packet DOES have a XOR based checksum at the end.
Our software does multiple things to check for bad packets, but if a packet is not received in full for whatever bluetoothy reason, it might be hard to recover from that unless you do lots of stuff. David's app for example using a voting system among other things to handle non-fully received packets.
We are looking into this improving the packet protocol.
The firmware and packet DOES have a XOR based checksum at the end.Thanks!
static bool is_valid(string input) {
if (input.Length != 52)
return false;
foreach (var c in input) {
if (!(Char.IsDigit(c) || Char.IsLetter(c)))
return false;
}
return true;
}
David's app for example using a voting system among other things to handle non-fully received packets.
We are looking into this improving the packet protocol.
But I guess you won't tell me how it is calculated or why it doesn't seem to be used in your app. At least I can't find it.
The implementation of the meter with a chipset that both Daves and UEi combined dont understand fully was risky. It was risky for the users as its their money that could have been spent on a comparable reliable meter with a fully functioning switch and mature firmware.
The implementation of the meter with a chipset that both Daves and UEi combined dont understand fully was risky. It was risky for the users as its their money that could have been spent on a comparable reliable meter with a fully functioning switch and mature firmware.
Even the big names like Keysight, Fluke, Gossen, Extech etc have all released meters that are less than perfect and have had a range of issues from hardware to software, lost calibration data in updates, bricking, to safety. If you've been watching my videos for a long time you'd know that. One of them almost killed or injured me due to a design flaw. These were all "reliable" released meters from huge reputable names.
I was just talking to one of them the other day commenting on the issues we've unfortunately been having, and they laughed and said they have had much more embarrassing problems in released products. Shit happens.
The implementation of the meter with a chipset that both Daves and UEi combined dont understand fully was risky. It was risky for the users as its their money that could have been spent on a comparable reliable meter with a fully functioning switch and mature firmware.
Even the big names like Keysight, Fluke, Gossen, Extech etc have all released meters that are less than perfect and have had a range of issues from hardware to software, lost calibration data in updates, bricking, to safety. If you've been watching my videos for a long time you'd know that. One of them almost killed or injured me due to a design flaw. These were all "reliable" released meters from huge reputable names.
I was just talking to one of them the other day commenting on the issues we've unfortunately been having, and they laughed and said they have had much more embarrassing problems in released products. Shit happens.
I don't have a 121GW or own one. However, many large corporations put out bug ridden and poorly built items. I think the big difference between them and Dave, is Dave cares. Instead of brushing things under the rug, ignoring or hiding them, avoiding any responsibility like so many companies do.
Hi.
Is there any chance for new batch of 121GW ? I see that it is out of stock.
Thx.
Do you know if there is any channel / information source that I can subscribe to see when multimeters will be available ?
At this point we are basically using the current user base as a testing platform to find and confirm bug fixes. There is nothing better than giving it to a few hundred people and getting feedback.
This is fine, but please "fix" things and don't "cover up".
The bluetooth transmission is broken by design and by implementation.
- There is no data integrity, aka. CRC or something on records (design error)
- The ASCII decimal/hex coding wastes more then 2/3 of the already scarce bluetooth bandwidth (design error)
- You have to check every single byte received for plausibility (and you'll fail in a lot of cases) (implementation error)
- If you look at the errors in the data it's clear that some buffer in the firmware get's overwritten (implementation error)
Would current owner prefer we not make interim firmware releases available for testing?
I'm fine with testing, no problem.
But the 1.07 -> 1.09 is not a fix, it's just trying to cover up above mentioned errors a bit better.
Start with fixing the missing CRC. Then errors can be detected reliably and automatically and one can trust the data received is what the firmware wanted to send.
Thx.
Do you know if there is any channel / information source that I can subscribe to see when multimeters will be available ?
If you install version 1.10 of the firmware you will also need to update the app.
You can do that on the Google Play / Window Store, (at least when they approve the update).
If I change the input to the meter for negative current, the meter displays the negative current correctly, but the app still displays the same wrong positive current.
Thx.
Do you know if there is any channel / information source that I can subscribe to see when multimeters will be available ?
Sign up for the newsletter
http://www.eevblog.com/newsletter/ (http://www.eevblog.com/newsletter/)
Many people still ask, and I don't know why people seaming don't quite understand that I have to deliver the Kickstarter units first before I sell to the general public.
--
1521739280.909 2023-08 02342 Power DC (VA) 1966.3 mVA DCA 205.12 0% f: 5%
1521739281.179 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.863 0% f: 5%
1521739281.517 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 2.1863 0% f: 5%
--
1521739349.017 2023-08 02342 Power DC (VA) 1967.2 mVA DCA 204.99 0% f: 5%
1521739349.287 2023-08 02342 Power DC (VA) 1967.2 mVA DCV 21.855 0% f: 5%
1521739349.557 2023-08 02342 Power DC (VA) 1967.2 mVA DCV 2.1855 0% f: 5%
--
1521739615.442 2023-08 02342 Power DC (VA) 1966.9 mVA DCA 204.99 0% f: 5%
1521739615.712 2023-08 02342 Power DC (VA) 1966.9 mVA DCV 21.862 0% f: 5%
1521739615.914 2023-08 02342 Power DC (VA) 1967.1 mVA DCV 2.1862 0% f: 5%
--
--
1521741169.774 2023-08 02342 Power DC (VA) 1966.2 mVA DCA 205.10 0% f: 5%
1521741170.044 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741170.584 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741170.854 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.192 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.327 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.597 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741171.799 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.070 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.272 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.541 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.880 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741173.352 2023-08 02342 Power DC (VA) 1966.7 mVA DCA 205.09 0% f: 5%
--
--
1521743502.116 2023-08 02342 Power DC (VA) 1968.8 mVA DCA 204.66 0% f: 5%
1521743502.589 2000-00 00040 Voltage LowZ (V) -0.61975 V 48% f: 5%
1521743502.859 2023-08 02342 Power DC (VA) 1968.7 mVA DCA 204.66 0% f: 5%
--
From the remaning 42k loglines with correct checksum 155 are broken
From the remaning 42k loglines with correct checksum 155 are broken
A XOR is not guaranteed to catch more than one byte errors, once in a while a multi byte error will slip through.
Ok, Version 1.10 is definitely a step forward but it still contains errors despite a correct checksum.
There is a pattern, when switching the second display from current to voltage in DC VA-mode the decimal point is wrong:Code: [Select]--
1521739280.909 2023-08 02342 Power DC (VA) 1966.3 mVA DCA 205.12 0% f: 5%
1521739281.179 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.863 0% f: 5%
1521739281.517 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 2.1863 0% f: 5%
--
1521739349.017 2023-08 02342 Power DC (VA) 1967.2 mVA DCA 204.99 0% f: 5%
1521739349.287 2023-08 02342 Power DC (VA) 1967.2 mVA DCV 21.855 0% f: 5%
1521739349.557 2023-08 02342 Power DC (VA) 1967.2 mVA DCV 2.1855 0% f: 5%
--
1521739615.442 2023-08 02342 Power DC (VA) 1966.9 mVA DCA 204.99 0% f: 5%
1521739615.712 2023-08 02342 Power DC (VA) 1966.9 mVA DCV 21.862 0% f: 5%
1521739615.914 2023-08 02342 Power DC (VA) 1967.1 mVA DCV 2.1862 0% f: 5%
--
But sometimes it stays wrong:Code: [Select]--
1521741169.774 2023-08 02342 Power DC (VA) 1966.2 mVA DCA 205.10 0% f: 5%
1521741170.044 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741170.584 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741170.854 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.192 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.327 2023-08 02342 Power DC (VA) 1966.3 mVA DCV 21.866 0% f: 5%
1521741171.597 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741171.799 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.070 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.272 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.541 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741172.880 2023-08 02342 Power DC (VA) 1966.7 mVA DCV 21.857 0% f: 5%
1521741173.352 2023-08 02342 Power DC (VA) 1966.7 mVA DCA 205.09 0% f: 5%
--
Sometimes I even get a wrong mode:Code: [Select]--
1521743502.116 2023-08 02342 Power DC (VA) 1968.8 mVA DCA 204.66 0% f: 5%
1521743502.589 2000-00 00040 Voltage LowZ (V) -0.61975 V 48% f: 5%
1521743502.859 2023-08 02342 Power DC (VA) 1968.7 mVA DCA 204.66 0% f: 5%
--
I collected arround 44k log records around 2k2 or 5% have a wrong checksum.
From the remaning 42k loglines with correct checksum 155 are broken, having either a wrong mode (66) a wrong decimal point(87) and 2 have some other parse error.
It does appear that you have the wrong app, try the other app avaliable on the app store. This is not the format that my app logs, so yeah it must be the wrong app.
https://play.google.com/store/apps/details?id=eevblog.x121gw&hl=en
20180324-10:07:40.176 2023-08 02342 Power DC (VA) 2005.9 mVA DCV 2.0987 0% f: 5%
20180324-10:07:40.648 error: unparsable record: Invalid year (0)
20180324-10:07:40.648 error: data: f2 00 00 01 40 00 d5 f2 17 80 23 42 18 00 4e 60 01 04 51
20180324-10:07:40.783 error: skiped 7 input bytes
20180324-10:07:40.783 2023-08 02342 Power DC (VA) 2006.4 mVA DCV 2.0978 0% f: 5%
--
20180324-10:08:42.006 2023-08 02342 Power DC (VA) 2006.2 mVA DCV 2.0978 0% f: 5%
20180324-10:08:42.478 error: unparsable record: Invalid year (0)
20180324-10:08:42.478 error: data: f2 00 00 01 40 00 eb f2 17 80 23 42 18 00 4e 5e 01 04 51
20180324-10:08:42.614 error: skiped 7 input bytes
20180324-10:08:42.614 2023-08 02342 Power DC (VA) 2006.2 mVA DCV 2.0978 0% f: 6%
--
20180324-10:09:19.199 2023-08 02342 Power DC (VA) 2006.2 mVA DCV 2.0978 0% f: 5%
20180324-10:09:19.671 error: unparsable record: Invalid year (0)
20180324-10:09:19.671 error: data: f2 00 00 01 40 00 eb f2 17 80 23 42 18 00 4e 5e 01 04 51
20180324-10:09:19.806 error: skiped 7 input bytes
20180324-10:09:19.806 2023-08 02342 Power DC (VA) 2006.2 mVA DCV 2.0978 0% f: 5%
--
20180324-10:11:36.427 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-10:11:36.900 error: unparsable record: Invalid year (0)
20180324-10:11:36.900 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:11:37.035 error: skiped 7 input bytes
20180324-10:11:37.035 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-10:12:51.825 2023-08 02342 Power DC (VA) 2006.6 mVA DCV 2.0978 0% f: 6%
20180324-10:12:52.297 error: unparsable record: Invalid year (0)
20180324-10:12:52.297 error: data: f2 00 00 01 40 00 d7 f2 17 80 23 42 18 00 4e 62 01 04 51
20180324-10:12:52.433 error: skiped 7 input bytes
20180324-10:12:52.433 2023-08 02342 Power DC (VA) 2006.6 mVA DCV 2.0978 0% f: 6%
--
20180324-10:16:26.477 2023-08 02342 Power DC (VA) 2006.6 mVA DCV 2.0978 0% f: 6%
20180324-10:16:26.949 error: unparsable record: Invalid year (0)
20180324-10:16:26.949 error: data: f2 00 00 01 40 00 d7 f2 17 80 23 42 18 00 4e 62 01 04 51
20180324-10:16:27.084 error: skiped 7 input bytes
20180324-10:16:27.084 2023-08 02342 Power DC (VA) 2006.6 mVA DCV 2.0978 0% f: 6%
--
20180324-10:18:36.415 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 5%
20180324-10:18:36.887 error: unparsable record: Invalid year (0)
20180324-10:18:36.887 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:18:37.022 error: skiped 7 input bytes
20180324-10:18:37.022 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-10:37:36.767 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 5%
20180324-10:37:37.239 error: unparsable record: Invalid year (0)
20180324-10:37:37.239 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:37:37.374 error: skiped 7 input bytes
20180324-10:37:37.374 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 5%
--
20180324-10:40:23.155 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-10:40:23.628 error: unparsable record: Invalid year (0)
20180324-10:40:23.628 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:40:23.763 error: skiped 7 input bytes
20180324-10:40:23.763 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0979 0% f: 6%
--
20180324-10:41:13.916 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-10:41:14.388 error: unparsable record: Invalid year (0)
20180324-10:41:14.388 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:41:14.523 error: skiped 7 input bytes
20180324-10:41:14.523 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-10:45:01.864 2023-08 02342 Power DC (VA) 2007.1 mVA DCV 2.0978 0% f: 6%
20180324-10:45:02.337 error: unparsable record: Invalid year (0)
20180324-10:45:02.337 error: data: f2 00 00 01 40 00 d2 f2 17 80 23 42 18 00 4e 67 01 04 51
20180324-10:45:02.472 error: skiped 7 input bytes
20180324-10:45:02.472 2023-08 02342 Power DC (VA) 2007.1 mVA DCV 2.0978 0% f: 6%
--
20180324-10:48:21.463 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-10:48:21.935 error: unparsable record: Invalid year (0)
20180324-10:48:21.935 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:48:22.071 error: skiped 7 input bytes
20180324-10:48:22.071 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-10:51:01.102 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-10:51:01.574 error: unparsable record: Invalid year (0)
20180324-10:51:01.574 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-10:51:01.709 error: skiped 7 input bytes
20180324-10:51:01.709 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-10:52:48.427 2023-08 02342 Power DC (VA) 2008.6 mVA DCA 204.66 0% f: 6%
20180324-10:52:48.900 error: unparsable record: Invalid year (0)
20180324-10:52:48.900 error: data: f2 00 00 01 40 00 cf f2 17 80 23 42 18 00 4e 76 15 02 4f
20180324-10:52:49.035 error: skiped 7 input bytes
20180324-10:52:49.035 2023-08 02342 Power DC (VA) 2008.6 mVA DCA 204.66 0% f: 6%
--
20180324-11:02:35.006 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0980 0% f: 5%
20180324-11:02:35.478 error: unparsable record: Invalid year (0)
20180324-11:02:35.478 error: data: f2 00 00 01 40 00 d0 f2 17 80 23 42 18 00 4e 65 01 04 51
20180324-11:02:35.613 error: skiped 7 input bytes
20180324-11:02:35.613 2023-08 02342 Power DC (VA) 2006.9 mVA DCV 2.0978 0% f: 5%
--
20180324-11:03:35.824 2023-08 02342 Power DC (VA) 2006.4 mVA DCV 2.0978 0% f: 5%
20180324-11:03:36.296 error: unparsable record: Invalid year (0)
20180324-11:03:36.296 error: data: f2 00 00 01 40 00 d5 f2 17 80 23 42 18 00 4e 60 01 04 51
20180324-11:03:36.431 error: skiped 7 input bytes
20180324-11:03:36.431 2023-08 02342 Power DC (VA) 2006.4 mVA DCV 2.0978 0% f: 6%
--
20180324-11:14:06.817 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
20180324-11:14:07.290 error: unparsable record: Invalid year (0)
20180324-11:14:07.290 error: data: f2 00 00 01 40 00 d1 f2 17 80 23 42 18 00 4e 64 01 04 51
20180324-11:14:07.425 error: skiped 7 input bytes
20180324-11:14:07.425 2023-08 02342 Power DC (VA) 2006.8 mVA DCV 2.0978 0% f: 6%
--
20180324-11:21:51.963 2023-08 02342 Power DC (VA) 2007.0 mVA DCV 2.0978 0% f: 6%
20180324-11:21:52.435 error: unparsable record: Invalid year (0)
20180324-11:21:52.435 error: data: f2 00 00 01 40 00 d3 f2 17 80 23 42 18 00 4e 66 01 04 51
20180324-11:21:52.570 error: skiped 7 input bytes
20180324-11:21:52.570 2023-08 02342 Power DC (VA) 2007.0 mVA DCV 2.0978 0% f: 6%
--
20180324-11:33:36.262 2023-08 02342 Power DC (VA) 2007.8 mVA DCA 204.75 0% f: 6%
20180324-11:33:36.734 error: unparsable record: Invalid year (0)
20180324-11:33:36.734 error: data: f2 00 00 01 40 00 db f2 17 80 23 42 18 00 4e 6e 01 04 51
20180324-11:33:36.870 error: skiped 7 input bytes
20180324-11:33:36.870 2023-08 02342 Power DC (VA) 2007.8 mVA DCV 2.0978 0% f: 6%
--
20180324-11:36:30.886 2023-08 02342 Power DC (VA) 2007.2 mVA DCV 2.0978 0% f: 6%
20180324-11:36:31.358 error: unparsable record: Invalid year (0)
20180324-11:36:31.358 error: data: f2 00 00 01 40 00 dd f2 17 80 23 42 18 00 4e 68 01 04 51
20180324-11:36:31.493 error: skiped 7 input bytes
20180324-11:36:31.493 2023-08 02342 Power DC (VA) 2007.2 mVA DCV 2.0978 0% f: 6%
20180325-21:31:47.828 error: invalid checksum: f2 17 80 23 42 18 00 25 45 01 04 70 1d 00 00 04 40 80 50
20180325-21:31:52.351 error: invalid checksum: f2 17 80 23 42 18 00 25 49 01 04 70 25 00 00 04 08 00 64
20180325-21:32:01.463 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 fb 1f 00 00 04 40 00 4e
20180325-21:32:06.053 error: invalid checksum: f2 17 80 23 42 06 00 25 46 01 04 70 20 00 00 04 40 00 6e
20180325-21:32:07.741 error: invalid checksum: f2 17 80 23 42 18 00 25 40 21 02 7e 22 00 00 04 40 00 76
20180325-21:32:11.521 error: invalid checksum: f2 17 80 23 42 18 00 25 47 01 04 70 01 00 00 04 40 00 6c
20180325-21:32:20.566 error: invalid checksum: f2 17 80 23 42 18 00 25 49 15 02 7e 07 00 00 04 40 00 43
20180325-21:32:25.089 error: invalid checksum: f2 17 80 23 42 18 40 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:32:26.844 error: invalid checksum: f2 17 80 23 42 18 00 25 a9 15 02 7e 21 00 00 04 40 00 0a
20180325-21:32:29.611 error: invalid checksum: f2 17 80 88 42 18 00 25 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:31.366 error: invalid checksum: f2 17 80 23 42 18 00 22 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:35.889 error: invalid checksum: f2 17 80 23 42 0c 00 25 44 01 04 70 14 00 00 04 40 00 58
20180325-21:32:48.714 error: invalid checksum: f2 17 80 23 42 18 00 25 40 01 00 70 0b 00 00 04 40 00 43
20180325-21:32:53.236 error: invalid checksum: f2 17 80 23 21 18 00 25 3e 15 02 7e 1d 00 00 04 40 00 37
20180325-21:32:54.991 error: invalid checksum: f2 17 80 23 42 18 00 25 09 01 04 70 01 00 00 04 40 00 37
20180325-21:32:57.759 error: invalid checksum: f2 17 80 23 42 01 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:32:59.446 error: invalid checksum: f2 17 80 23 10 18 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:33:09.571 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 7e 07 00 00 04 40 00 4e
20180325-21:33:12.339 error: invalid checksum: f2 17 80 23 42 01 00 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:33:14.161 error: invalid checksum: f2 17 80 23 42 18 00 25 43 20 04 70 16 00 00 04 40 00 5d
It does appear that you have the wrong app, try the other app avaliable on the app store. This is not the format that my app logs, so yeah it must be the wrong app.
https://play.google.com/store/apps/details?id=eevblog.x121gw&hl=en
I also had the problem with your android app, that I couldn't save the log when I left it running once over night. When pressing save the app just froze for some seconds and then continued. Maybe my phone has too little memory.
I'll look into this, not sure what caused it but i'll do my best to reproduce, it may take a while to reproduce these type of issues can sometimes take a while to figure out the exact mechanism as its likely something specific about the android API. I'll get back to you or just release a fix as an update if it is reproducible.
Here are some records with failing xor checksums:Code: [Select]20180325-21:31:47.828 error: invalid checksum: f2 17 80 23 42 18 00 25 45 01 04 70 1d 00 00 04 40 80 50
20180325-21:31:52.351 error: invalid checksum: f2 17 80 23 42 18 00 25 49 01 04 70 25 00 00 04 08 00 64
20180325-21:32:01.463 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 fb 1f 00 00 04 40 00 4e
20180325-21:32:06.053 error: invalid checksum: f2 17 80 23 42 06 00 25 46 01 04 70 20 00 00 04 40 00 6e
20180325-21:32:07.741 error: invalid checksum: f2 17 80 23 42 18 00 25 40 21 02 7e 22 00 00 04 40 00 76
20180325-21:32:11.521 error: invalid checksum: f2 17 80 23 42 18 00 25 47 01 04 70 01 00 00 04 40 00 6c
20180325-21:32:20.566 error: invalid checksum: f2 17 80 23 42 18 00 25 49 15 02 7e 07 00 00 04 40 00 43
20180325-21:32:25.089 error: invalid checksum: f2 17 80 23 42 18 40 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:32:26.844 error: invalid checksum: f2 17 80 23 42 18 00 25 a9 15 02 7e 21 00 00 04 40 00 0a
20180325-21:32:29.611 error: invalid checksum: f2 17 80 88 42 18 00 25 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:31.366 error: invalid checksum: f2 17 80 23 42 18 00 22 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:35.889 error: invalid checksum: f2 17 80 23 42 0c 00 25 44 01 04 70 14 00 00 04 40 00 58
20180325-21:32:48.714 error: invalid checksum: f2 17 80 23 42 18 00 25 40 01 00 70 0b 00 00 04 40 00 43
20180325-21:32:53.236 error: invalid checksum: f2 17 80 23 21 18 00 25 3e 15 02 7e 1d 00 00 04 40 00 37
20180325-21:32:54.991 error: invalid checksum: f2 17 80 23 42 18 00 25 09 01 04 70 01 00 00 04 40 00 37
20180325-21:32:57.759 error: invalid checksum: f2 17 80 23 42 01 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:32:59.446 error: invalid checksum: f2 17 80 23 10 18 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:33:09.571 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 7e 07 00 00 04 40 00 4e
20180325-21:33:12.339 error: invalid checksum: f2 17 80 23 42 01 00 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:33:14.161 error: invalid checksum: f2 17 80 23 42 18 00 25 43 20 04 70 16 00 00 04 40 00 5d
I don't really understand what's happening here. It looks a bit like random bit errors. could it be a birate mismatch between CPU and BLE module?
Maybe someone with more experience with this kind of errors can comment on this.
Here are some records with failing xor checksums:Code: [Select]20180325-21:31:47.828 error: invalid checksum: f2 17 80 23 42 18 00 25 45 01 04 70 1d 00 00 04 40 80 50
20180325-21:31:52.351 error: invalid checksum: f2 17 80 23 42 18 00 25 49 01 04 70 25 00 00 04 08 00 64
20180325-21:32:01.463 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 fb 1f 00 00 04 40 00 4e
20180325-21:32:06.053 error: invalid checksum: f2 17 80 23 42 06 00 25 46 01 04 70 20 00 00 04 40 00 6e
20180325-21:32:07.741 error: invalid checksum: f2 17 80 23 42 18 00 25 40 21 02 7e 22 00 00 04 40 00 76
20180325-21:32:11.521 error: invalid checksum: f2 17 80 23 42 18 00 25 47 01 04 70 01 00 00 04 40 00 6c
20180325-21:32:20.566 error: invalid checksum: f2 17 80 23 42 18 00 25 49 15 02 7e 07 00 00 04 40 00 43
20180325-21:32:25.089 error: invalid checksum: f2 17 80 23 42 18 40 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:32:26.844 error: invalid checksum: f2 17 80 23 42 18 00 25 a9 15 02 7e 21 00 00 04 40 00 0a
20180325-21:32:29.611 error: invalid checksum: f2 17 80 88 42 18 00 25 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:31.366 error: invalid checksum: f2 17 80 23 42 18 00 22 42 01 04 70 0c 00 00 04 40 00 46
20180325-21:32:35.889 error: invalid checksum: f2 17 80 23 42 0c 00 25 44 01 04 70 14 00 00 04 40 00 58
20180325-21:32:48.714 error: invalid checksum: f2 17 80 23 42 18 00 25 40 01 00 70 0b 00 00 04 40 00 43
20180325-21:32:53.236 error: invalid checksum: f2 17 80 23 21 18 00 25 3e 15 02 7e 1d 00 00 04 40 00 37
20180325-21:32:54.991 error: invalid checksum: f2 17 80 23 42 18 00 25 09 01 04 70 01 00 00 04 40 00 37
20180325-21:32:57.759 error: invalid checksum: f2 17 80 23 42 01 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:32:59.446 error: invalid checksum: f2 17 80 23 10 18 00 25 3d 15 02 7e 20 00 00 04 40 00 09
20180325-21:33:09.571 error: invalid checksum: f2 17 80 23 42 18 00 25 45 15 02 7e 07 00 00 04 40 00 4e
20180325-21:33:12.339 error: invalid checksum: f2 17 80 23 42 01 00 25 43 01 04 70 16 00 00 04 40 00 5d
20180325-21:33:14.161 error: invalid checksum: f2 17 80 23 42 18 00 25 43 20 04 70 16 00 00 04 40 00 5d
I don't really understand what's happening here. It looks a bit like random bit errors. could it be a birate mismatch between CPU and BLE module?
Maybe someone with more experience with this kind of errors can comment on this.
This looks like a baudrate problem, or maybe wrong start bit detection or something like this. E.g. when 0x42 turns into 0x21, one bit shifted to the right. Same for 0x18 turning int 0x0c, one bit shifted.
Very unlikely that it has anything to do with the RF transfer from the Bluetooth module to the receiver, because as I noted earlier, BLE has a sophisticated error correction. Not just xor, but CRC, which is easy to calculate with tables, I've implemented this once myself for another product. You can verify this if you increase the distance: there shouldn't be more errors, but it gets slower, because packets gets resend, at least when I tested it with my Blue Gecko Silabs IC, which had no packet errors at all at the application level.
Maybe you can measure the RX/TX lines between the Bluetooth module and the CPU to check if the baudrate is exact in your multimeter, if David can't reproduce it?
Alright so I've logged data for 2 minutes on BLE and UART then validated the packets, it doesn't appear i'm getting any of the bad packets on android.
Similarly on windows there were no bad packets.
Do you have any specific conditions which might help reproduce this issue.
NOTE: If you compile my main C++ file be sure to set struct alignment to be for bytes not like 32 bit integers or something, often the default is not byte.
Alright so I've logged data for 2 minutes on BLE and UART then validated the packets, it doesn't appear i'm getting any of the bad packets on android.
Similarly on windows there were no bad packets.
Do you have any specific conditions which might help reproduce this issue.
NOTE: If you compile my main C++ file be sure to set struct alignment to be for bytes not like 32 bit integers or something, often the default is not byte.
Thanks a lot. Yes, your data looks good.
Can you explain how to log the raw data on android?
Then I'd like to try this with my meter to see if the problem is still there.
I tried with 3 different linux systems, my desktop, a thinkpad X230 and a thinkpad X220. They all show the same invalid records.
Maybe I have a bad meter?
I tried with 3 different linux systems, my desktop, a thinkpad X230 and a thinkpad X220. They all show the same invalid records.
Maybe I have a bad meter?
I tried with 3 different linux systems, my desktop, a thinkpad X230 and a thinkpad X220. They all show the same invalid records.
Maybe I have a bad meter?
Do you have any issues at all with the range switch?
There is a possibility that could be an issue.
I tried with 3 different linux systems, my desktop, a thinkpad X230 and a thinkpad X220. They all show the same invalid records.
Maybe I have a bad meter?
Do you have any issues at all with the range switch?
There is a possibility that could be an issue.
I'll look into this, not sure what caused it but i'll do my best to reproduce, it may take a while to reproduce these type of issues can sometimes take a while to figure out the exact mechanism as its likely something specific about the android API. I'll get back to you or just release a fix as an update if it is reproducible.
Thanks, but don't spend much time on this. Short logs are working fine. The fault could also be my phone I just tried it once.
I'd be much more interested if you can see the same data errors that I see with my linux script.
Maybe you could add logging of these failed records raw data to your app, so that I can compare these?
At the moment raw packet logging is not a feature of the app, I use debug outputs (in visual studio, with debug mode) to get the data.
There are a fair few apps on the play store which seem suitable, I haven't used these but they appear to do what you want:
https://play.google.com/store/apps/details?id=com.zicasoftware.ziblemonitor
https://play.google.com/store/apps/details?id=com.edodm85.bluetoothbleterminal.free
I was thinking of the spurious VA values. We no longer get these as it's been (as far as we can tell) fixed in software. So if spurious values are being seen, maybe that's a possible cause?
But if it's a checksum thing, then forget I said it.
But as I believe David (seppy) has said, we are no longer getting corrupted data, and hence no more checksum errors.
How could the range switch cause invalid xor checksums?
With V1.10 I still see wrong voltage and current displays in certain parts of the measuring range, I see a spurious wrong decimal point in current display and I see wrong range display (A instead of mA) in the current display. All of this in DC VA-mode.
Apart from that the displayed values are consistently wrong.
I guess the invalid checksums must then be some electrical problem in my meter if no one else can see them.
With V1.10 I still see wrong voltage and current displays in certain parts of the measuring range, I see a spurious wrong decimal point in current display and I see wrong range display (A instead of mA) in the current display. All of this in DC VA-mode.
Apart from that the displayed values are consistently wrong.
On the meter display or the app display? (or both)
Does the SD card logged data show correct or incorrect readings?
I guess the invalid checksums must then be some electrical problem in my meter if no one else can see them.
Again, how are you validating your checksums? with your own software?
I updated the meter to 1.10 and now the iphone app doesn't work. it connects (apparently) but there is no meter display in the app.
Any ideas? Fixes? Any idea when a real eevblog iOS app will be released?
I updated the meter to 1.10 and now the iphone app doesn't work. it connects (apparently) but there is no meter display in the app.
Any ideas? Fixes? Any idea when a real eevblog iOS app will be released?
The Bluetooth protocol changed, you have to use the correct application version (I do not know that yet, I am still waiting on my meter).
Should I downgrade the firmware? Will that work? Any idea to what version? I use that app!
I updated the meter to 1.10 and now the iphone app doesn't work. it connects (apparently) but there is no meter display in the app.
Any ideas? Fixes? Any idea when a real eevblog iOS app will be released?
I updated the meter to 1.10 and now the iphone app doesn't work. it connects (apparently) but there is no meter display in the app.
Any ideas? Fixes? Any idea when a real eevblog iOS app will be released?
The Bluetooth packet changed as has been discussed on here.
We (EEVblog "we", not UEi) do not endorse nor have control over the UEi application that is currently on the iPhone store. We are not aware of if or when they are updating that.
David is starting working on the iPhone version shortly, we now have a mac setup to enable the compiler to do this.
Thanks Dave that's good news. Looking forward to a spiffy iOS app.
Thanks Dave that's good news. Looking forward to a spiffy iOS app.
In theory it's as easy as pressing Compile for iOS, but we have not done this before, so :-//
But remember, iOS users are used to a particular look and feel.
But remember, iOS users are used to a particular look and feel.
Sleek, stylish, streamlined - and it sets the parameters and tells the user what to do, because it knows best.
..a good iOS app will inspire meter sales.Today's headlines: "Thousands of seniors and trendy spoon-fed millennials suddenly adopt electronics as a hobby" :-DD
At the moment raw packet logging is not a feature of the app, I use debug outputs (in visual studio, with debug mode) to get the data.
At the moment raw packet logging is not a feature of the app, I use debug outputs (in visual studio, with debug mode) to get the data.
I would still suggest you include the feature in your app.
It might be the linux bluetooth stack that is the reason for the errors, but it might also be some electrical problem with pullup/diode level shifter (R76/D4 in the schematic) in my (or others) meter. Maybe the resulting voltages are too narrowly specified.
With that feature more people could check easily if that's the case on more meters.
Can you reproduce the following measurements?
2.0V peak to peak sine wave 4kHz, No DC offset, duty cycle 50%. Both meters in AC mode. Firmware 1.07 on my 121GW with serial number EEVblog 000084
Auto mode on both meters, Fluke in highres mode:
121GW selects 5V range, reads 1.1133Vac
Fluke 28II selects 6V range, reads 0.7031Vac
manual mode on both meters:
121GW 5V range, reads 1.1133Vac
Fluke 28II 6V range, 0.7032Vac
121GW 50V range, reads 0.659Vac (and it looses the frequency measurement and displays 0.00kHz)
Fluke 28II 60V range, reads 0.663Vac
See the attached pictures.
Since the 121GW seems to have an UART, I'd like to know precisely
where to get at the UART signals.
Are these at Pin 122 on U4 for Rx and Pin 119 for Tx?
Finally conduct updating the firmware of my 121GW multimeter.
I am happy with the autorange speed.
https://youtu.be/6Y1KzSA-BUE
Dave thanks for the last update on these meters. Since some people have cancelled and the meters have already been ordered, would it be possible to order more meters?
Oh can't wait. Need a new DMM.
I re-checked with 1.10 and get the same results. Can someone confirm my measurements?
Why is the 121GW reading wrong in auto range/manual 5V range in this situation?Can you reproduce the following measurements?
2.0V peak to peak sine wave 4kHz, No DC offset, duty cycle 50%. Both meters in AC mode. Firmware 1.07 on my 121GW with serial number EEVblog 000084
Auto mode on both meters, Fluke in highres mode:
121GW selects 5V range, reads 1.1133Vac
Fluke 28II selects 6V range, reads 0.7031Vac
manual mode on both meters:
121GW 5V range, reads 1.1133Vac
Fluke 28II 6V range, 0.7032Vac
121GW 50V range, reads 0.659Vac (and it looses the frequency measurement and displays 0.00kHz)
Fluke 28II 60V range, reads 0.663Vac
See the attached pictures.
I re-checked with 1.10 and get the same results. Can someone confirm my measurements?
Why is the 121GW reading wrong in auto range/manual 5V range in this situation?Can you reproduce the following measurements?
2.0V peak to peak sine wave 4kHz, No DC offset, duty cycle 50%. Both meters in AC mode. Firmware 1.07 on my 121GW with serial number EEVblog 000084
Auto mode on both meters, Fluke in highres mode:
121GW selects 5V range, reads 1.1133Vac
Fluke 28II selects 6V range, reads 0.7031Vac
manual mode on both meters:
121GW 5V range, reads 1.1133Vac
Fluke 28II 6V range, 0.7032Vac
121GW 50V range, reads 0.659Vac (and it looses the frequency measurement and displays 0.00kHz)
Fluke 28II 60V range, reads 0.663Vac
See the attached pictures.
1) Should the 500V AC VA mode be added at the expense of a few of the other lower ranges?
2) Is AC VA mode even useful to people? (obviously the DC VA mode is)
1) Should the 500V AC VA mode be added at the expense of a few of the other lower ranges?
2) Is AC VA mode even useful to people? (obviously the DC VA mode is)
Hello,
As don't have the 121GW yet was wondering before ordering if the PC Gui logging software will work with one of these please:
https://www.overclockers.co.uk/asus-usb-bt400-bluetooth-4.0-usb-adaptor-nw-076-as.html (https://www.overclockers.co.uk/asus-usb-bt400-bluetooth-4.0-usb-adaptor-nw-076-as.html)
Many thanks
Hello,
As don't have the 121GW yet was wondering before ordering if the PC Gui logging software will work with one of these please:
https://www.overclockers.co.uk/asus-usb-bt400-bluetooth-4.0-usb-adaptor-nw-076-as.html (https://www.overclockers.co.uk/asus-usb-bt400-bluetooth-4.0-usb-adaptor-nw-076-as.html)
Many thanks
Any 4.0 adapter that supports BLE mode should work.
I'm now asking if it's worthwhile having the 500V/10A AC VA range at all? I can't personally, but I'm not really an AC industry guy.
With regards to the requested 500V/5A (250VA) VA power mode.Is that 2500VA?
It is possible to add this (with some sacrifice in other ranges), and we have tested a solution.What is the sacrifice exactly? Isn't the next range down 500mVAC.
But now I'm I am wondering whether or not it's actually worthwhile?Doe's this mean Joe noob (ie me) looking around for things to measure won't be able to look at all my energy wasting 110VAC stuff. I think my new fangled utility meter bills me measuring only VA?
After all the meter is only capable of measuring VA and not true Watts, as the chipset does not have the phase measurement capability.
With this in mind, how useful is VA measurement in AC mode to people without a true Watts capability?
Doe's this mean Joe noob (ie me) looking around for things to measure won't be able to look at all my energy wasting 110VAC stuff. I think my new fangled utility meter bills me measuring only VA?
Doe's this mean Joe noob (ie me) looking around for things to measure won't be able to look at all my energy wasting 110VAC stuff. I think my new fangled utility meter bills me measuring only VA?
The 5V range does appear wrong on your meter but we haven't been able to reproduce it, it could be an issue with your unit in that range.HZ range functions well up to about 720kHz in the Hz mode, and up to 680kHz in V mode on the second display (with a sine 2Vpp).
Can you confirm that the Hz range functions correctly on your meter?
Can you also test the same range with 400Hz?
Is that 2500VA?
What is the sacrifice exactly? Isn't the next range down 500mVAC.
Doe's this mean Joe noob (ie me) looking around for things to measure won't be able to look at all my energy wasting 110VAC stuff. I think my new fangled utility meter bills me measuring only VA?
I was thinking of the spurious VA values. We no longer get these as it's been (as far as we can tell) fixed in software. So if spurious values are being seen, maybe that's a possible cause?
But if it's a checksum thing, then forget I said it.
But as I believe David (seppy) has said, we are no longer getting corrupted data, and hence no more checksum errors.
How could the range switch cause invalid xor checksums?
I don't see spurious VA values as in the early versions of the firmware.
With V1.10 I still see wrong voltage and current displays in certain parts of the measuring range, I see a spurious wrong decimal point in current display and I see wrong range display (A instead of mA) in the current display. All of this in DC VA-mode.
Apart from that the displayed values are consistently wrong.
I guess the invalid checksums must then be some electrical problem in my meter if no one else can see them.
As there seems no way to debug it further, I can't help you there.
Only thing i would change if possible would be the ability to remove/swap the micro sd card without taking the back off, a little hatch would be great and well if you do consider it
Only thing i would change if possible would be the ability to remove/swap the micro sd card without taking the back off, a little hatch would be great and well if you do consider it
This has been mentioned before - but I believe the issue is one of safety. The Cat ratings and safety design of the 121GW is based on the only access to the meter's circuitry being through the probe sockets on the front - which have been designed to certain standards.
To access the microSD card, you would be given access to the microSD card slot - which is connected to the meter's innards. Such an interface would need very special consideration to be suitably rated - if, indeed, that were at all possible. Since the microSD facility was a "fit in", the restriction on access in order to maintain safety and the Cat ratings is one that will (as I understand it) have to stand.
Hey Dave, should I start checking my letterbox anytime soon for a delivery?
It must be getting very close by now for the Johnny B Goode shipment to be shipped.
Looking forward to playing with this meter sometime very soon :-+
Yes, it's an issue of access safety.
I know it's a bit of a PITA, but it takes under 20 seconds to remove the boot, unscrew the cover and remove the SD card and insert into computer.
If you need more accessible data logging then I'd recommend a proper data logger. This is a multimeter first with some SD logging capability, not the other way around.
I guess you could always dremel a slot in the back perhaps?
I would have imagined trying to have the SD card slot under the battery cover rather than having to open the whole meter to access it...?
Why don't you make the SD card slot from the side like laptops? just a hole\slot in the side of the multimeter and it will be perfect. The holster will hide and protect it.But it's not in the same compliance category as a laptop, so it wouldn't have passed standards testing.
I guess you could always dremel a slot in the back perhaps?:scared:
Why don't you make the SD card slot from the side like laptops? just a hole\slot in the side of the multimeter and it will be perfect. The holster will hide and protect it.But it's not in the same compliance category as a laptop, so it wouldn't have passed standards testing.
(EC 60950 talks about "Emission of flame or expulsion of molten metal")
I guess you could always dremel a slot in the back perhaps?:scared:
Would one of those WiFi-enabled SD cards work?
IIRC the Mooshimeter had the same issue with testing and its SD card slot and also opted for a slot that required opening the case to access.
IIRC the Mooshimeter had the same issue with testing and its SD card slot and also opted for a slot that required opening the case to access.
Correct.
The one I have has thinner indented plastic molding where the slot was in the original design.
The guy who designed the meter had to change the injection mold to comply with the required safety standards.
However, the end user can easily snap out the plastic to make a slot if they wish - at their own risk of course.
I don’t know if something similar could have been done with the 121GW
I wonder about something... Why don't mutlimeters come with rechargeable batteries such as Li-ion\Li-Po? with capability to charge it with micro USB plug.
I suspect that it won't pass tests for safety or so, but I need the correct answer.
4) Access for charging internal batteries would compromise safety - just as having external access to the internal microSD card would be on the 121GW
I wonder about something... Why don't mutlimeters come with rechargeable batteries such as Li-ion\Li-Po? with capability to charge it with micro USB plug.
I suspect that it won't pass tests for safety or so, but I need the correct answer.
4) Access for charging internal batteries would compromise safety - just as having external access to the internal microSD card would be on the 121GW
Guess this is how you get around the safety issues of rechargeable MM
https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7 (https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7)
Guess this is how you get around the safety issues of rechargeable MM
https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7 (https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7)
If there is an affordable good meter like 121gw but with rechargeable battery, I would buy it.
Guess this is how you get around the safety issues of rechargeable MM
https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7 (https://www.alibaba.com/product-detail/Rechargeable-Self-Restoring-LCD-Digital-Multimeter_60366637118.html?spm=a2700.7724857.main07.8.198777e4cV0KF7)
This meter has something I like : polyfuses
Why don't other meters use them?
Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
Overall size and weight especially with lithium ion.Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
Again, it adds complexity and cost, to what purpose? What is the point?
Cell phones get charged every few days, so convenient recharging is relevant.
Multimeters get recharged every few months, maybe once a year. So what problem does a built-in rechargeable battery solve?
Joe Smith did some DMM logging tests with Bluetooth and it certainly can chew up batteries whereas if a DMM was logging while parked in an inductive charging cradle long term battery live would no longer be part of the picture.
Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
I was thinking of very long datalogging sessions, and perhaps using a meter that is not so low-power to last 500+ hours.Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
No point when your meter has 500+ hours battery life, and you can change the batteries available anywhere.
Is this 500 hours of battery life while actively logging to an SD card and broadcasting serial Bluetooth signals? I have a logging meter, it doesn’t get any battery life like a normal one does with a single 9V.Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?
No point when your meter has 500+ hours battery life, and you can change the batteries available anywhere.
4) Access for charging internal batteries would compromise safety - just as having external access to the internal microSD card would be on the 121GWHow would access to the SD card compromise safety?
Because the DMM's 0V rail could be connected to several hundred volts4) Access for charging internal batteries would compromise safety - just as having external access to the internal microSD card would be on the 121GWHow would access to the SD card compromise safety?
Because the DMM's 0V rail could be connected to several hundred volts4) Access for charging internal batteries would compromise safety - just as having external access to the internal microSD card would be on the 121GWHow would access to the SD card compromise safety?
Ok, I know I dropped a $20 meter for an example,but the fluke 289 works the same way. The receiving IR and PCB/Chip is not connected to the main DMM PCB at all, in fact it’s powered by the 5VDC from the USB port. So forgive me if I wrong, but I still don’t see how that would be possible.
Ok, I know I dropped a $20 meter for an example,but the fluke 289 works the same way. The receiving IR and PCB/Chip is not connected to the main DMM PCB at all, in fact it’s powered by the 5VDC from the USB port. So forgive me if I wrong, but I still don’t see how that would be possible.
Because the SD card does not have onboard power like a USB port, and so the SD card driver has to be powered by the meter's internal circuitry, which means there is an electrical path between the terminals of the meter and the SD card.
But a good (for a cheap) power meter like the Zhurui PR10 (https://www.aliexpress.com/store/group/Power-Recorder/427884_509189231.html) will do fine down to 5mA at 230V. Takes 0.1 watts to display power though.You should not be using a multimeter like this for your appliances, just but a cheap Kill-A-Watt unit that measures proper W and VA power.I did not think the Killawatt could read very low power levels.
Most utilities will charge in W, not VA for residential customers, but that varies depending upon the country and utility company.
121GW battery life vs battery type.
As far as the 500 hr battery life claim is this for alkaline or NiCad and what mah rating
My camera packs up much earlier on nicad than on fresh alkaline as the static voltage is lower for NiCad's
Any 121GW test data for various battery chemistry yet?
Is this 500 hours of battery life while actively logging to an SD card and broadcasting serial Bluetooth signals?
Is this 500 hours of battery life while actively logging to an SD card and broadcasting serial Bluetooth signals?
No, logging is lower, but don't have accurate specs for that. SD drops it to a few hundred hours IIRC. Have not tested Bluetooth, but it's BLE at a low sample rate so shouldn't take much.
121GW battery life vs battery type.
As far as the 500 hr battery life claim is this for alkaline or NiCad and what mah rating
My camera packs up much earlier on nicad than on fresh alkaline as the static voltage is lower for NiCad's
Any 121GW test data for various battery chemistry yet?
4.2V dropout voltage, approx 5mA consumption, you can do the math with whatever chemistry.
The spec is Alkaline.
3200 mah Ni-MH would real push the envelope, think two sets of these would be why for me to go :-)
121GW battery life vs battery type.
As far as the 500 hr battery life claim is this for alkaline or NiCad and what mah rating
My camera packs up much earlier on nicad than on fresh alkaline as the static voltage is lower for NiCad's
Any 121GW test data for various battery chemistry yet?
4.2V dropout voltage, approx 5mA consumption, you can do the math with whatever chemistry.
The spec is Alkaline.
Well quick math looks like a 2400 mah AA NiCd down to 10% charge will still run the 121GW, so still in the region of 500 hr run time.
3200 mah Ni-MH would real push the envelope, think two sets of these would be why for me to go :-)
No mention of a supply date yet, so makes me wonder if not some under the covers magic being worked out 8)
@EEVBlog Just receive a "last minute address change" notification from KS. Are the US units about to be shipped?
Welectron for the EUHi, Dave. I have also received "last minute address change" e-mail, but I have not received the PayPal VAT invoices yet. Have you sent them? I am in Johnny B. Goode group and I chose the EU shipping option. Please be so kind and post an update to Kickstarter as soon as you send the invoices, so we do not miss something.
@EEVBlog Just receive a "last minute address change" notification from KS. Are the US units about to be shipped?
Yes, we had to lock down the address changes and KS makes us wait 48hours. We actually have like 150 or something last minutes changes!
1000 units will be available end of April (as in available to ship to the various distributors, Welectron for the EU, here for Oz/NZ/others, EUi/KaneTest for the US)
and another 1000 units end of May
(so I guess their production capacity is 1000 units a month)
As before, the remainder of the Great Scott backers will be shipped first. But given that there will be a lot of leftover units from the first 1000 unit batch, many Johnny B. Goode backers will get theirs at the same time.
@EEVBlog Just receive a "last minute address change" notification from KS. Are the US units about to be shipped?
Yes, we had to lock down the address changes and KS makes us wait 48hours. We actually have like 150 or something last minutes changes!
1000 units will be available end of April (as in available to ship to the various distributors, Welectron for the EU, here for Oz/NZ/others, EUi/KaneTest for the US)
and another 1000 units end of May
(so I guess their production capacity is 1000 units a month)
As before, the remainder of the Great Scott backers will be shipped first. But given that there will be a lot of leftover units from the first 1000 unit batch, many Johnny B. Goode backers will get theirs at the same time.
Would some kind of inductive powering (like Qi charging) feasible in a safe way in a meter, if the receiving antenna is e.g. well inside the body of the instrument, like the battery compartment?The main issue is that the inductive field will couple into the analogue front end and maybe throw it out of spec - semiconductor junctions can act as rectifiers and cause an offset on the measurement. I design inductively powered devices and just measuring small signals in the presence of a HF band inductive field can be challenging at times. Unlike electric fields it's not trivial to make a device immune to HF band magnetic fields - thin metal cans do diddly squat. A better solution would just be to power it with a properly isolated DC-DC supply.
@EEVBlog Just receive a "last minute address change" notification from KS. Are the US units about to be shipped?
Yes, we had to lock down the address changes and KS makes us wait 48hours. We actually have like 150 or something last minutes changes!
1000 units will be available end of April (as in available to ship to the various distributors, Welectron for the EU, here for Oz/NZ/others, EUi/KaneTest for the US)
and another 1000 units end of May
(so I guess their production capacity is 1000 units a month)
As before, the remainder of the Great Scott backers will be shipped first. But given that there will be a lot of leftover units from the first 1000 unit batch, many Johnny B. Goode backers will get theirs at the same time.
@EEVBlog Just receive a "last minute address change" notification from KS. Are the US units about to be shipped?
Yes, we had to lock down the address changes and KS makes us wait 48hours. We actually have like 150 or something last minutes changes!
1000 units will be available end of April (as in available to ship to the various distributors, Welectron for the EU, here for Oz/NZ/others, EUi/KaneTest for the US)
and another 1000 units end of May
(so I guess their production capacity is 1000 units a month)
As before, the remainder of the Great Scott backers will be shipped first. But given that there will be a lot of leftover units from the first 1000 unit batch, many Johnny B. Goode backers will get theirs at the same time.
A bit confused here - are the US Great Scott units being shipped from the fixed units from before or are they coming from this new batch being shipped at the end of April? Basically just wondering what happened to the original great scott units that made it through customs into the US before they got redirected to KaneTest.
Is it a fair teat to connect several meters together in ohms mode and drawing conclusions from how they behave? Several meters trying to push sequences of various currents and interpreting the resulting voltage. Chaos. Might work ok with shorted probes, but still...
...Yes, you need help :-+
I think I need to join the therapy thread. :)
..
Does your wife know? :-DD Looking forward to seeing the high resolution pictures of the two meters.
Is it a fair teat to connect several meters together in ohms mode and drawing conclusions from how they behave? Several meters trying to push sequences of various currents and interpreting the resulting voltage. Chaos. Might work ok with shorted probes, but still...
That was my initial reaction when I first saw that sort of setup - but I think the answer is that it can only work with shorted probes.
There's already a fancy Agilent and another Hioki in the background so I guess he knows what he's doing.Then the reply was silence....
:-DD :-DD
Is it a fair teat to connect several meters together in ohms mode and drawing conclusions from how they behave? Several meters trying to push sequences of various currents and interpreting the resulting voltage. Chaos. Might work ok with shorted probes, but still...
That was my initial reaction when I first saw that sort of setup - but I think the answer is that it can only work with shorted probes.
I thought the same.
I worried first of damaging the multimeters by current flowing from other multimeters when connecting together.
My brain still only has analog meter age and it might stress the battery inside.
( Then I thought if digital multimeter was so fragile, it would not survive joe's robustness test. :) )
Ok, so it’s a technicality but this idea might work?Does your wife know? :-DD Looking forward to seeing the high resolution pictures of the two meters.
My wife fount it out..... She saw my video.....
So I told her that you are globally famous which is a good thing :)
Then the reply was silence....
I do not feel I could buy any more multimeter in my life :'(
Ok, so it’s a technicality but this idea might work?
You don’t BUY anymore, just do what some other youtubers do.
Contact bangood and they will send you meters. Then your not buying any of them.
My thoughts on the difference in speed for the readings in addition to what others mentioned.Is it a fair teat to connect several meters together in ohms mode and drawing conclusions from how they behave? Several meters trying to push sequences of various currents and interpreting the resulting voltage. Chaos. Might work ok with shorted probes, but still...
That was my initial reaction when I first saw that sort of setup - but I think the answer is that it can only work with shorted probes.
I thought the same.
I am not sure it is in the video, I printed out the spec pages of all multimeters (I had them on right side of the desk) and on manual of DT4282 had the current for every ohm range used, and TY720 had the maximum current could be used for every ohm range. All of the currents were different.
I worried first of damaging the multimeters by current flowing from other multimeters when connecting together.
My brain still only has analog meter age and it might stress the battery inside.
( Then I thought if digital multimeter was so fragile, it would not survive joe's robustness test. :) )
And the shorting the probe all the current from all meters of all ranges could be the same behavior even for the individually shorting the probe.
End up connecting all multmeters together. I am too lazy to make some jig for taking video. :)
There’s a therapy thread? Please share, my best friend needs multimeter obsession help. :-DDOk, so it’s a technicality but this idea might work?
You don’t BUY anymore, just do what some other youtubers do.
Contact bangood and they will send you meters. Then your not buying any of them.
There's a place that sends you free multimeters? For free?
Don't let that information reach the therapy thread. :scared:
There's a place that sends you free multimeters? For free?There’s a therapy thread? Please share, my best friend needs multimeter obsession help. :-DD
Don't let that information reach the therapy thread. :scared:
There's a place that sends you free multimeters? For free?There’s a therapy thread? Please share, my best friend needs multimeter obsession help. :-DD
Don't let that information reach the therapy thread. :scared:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/ (https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/)
I thought they would have shipped by now.According to yesterday’s update I guess the shipping information update request was only for people to receive the PCB and switch fix, not for shipping meters to others. That wasn’t clear, so as it stands not ETA on when the meters will resume shipping. Well this a the official statement “ future shipments which should be commencing again shortly.”
So much for Christmas. Funny is that you bought it for an early review and even though we are several months into the KS, even if it takes a half year for you to see the meter, you may still be one of the first reviewers. :-DDI thought they would have shipped by now.According to yesterday’s update I guess the shipping information update request was only for people to receive the PCB and switch fix, not for shipping meters to others. That wasn’t clear, so as it stands not ETA on when the meters will resume shipping. Well this a the official statement “ future shipments which should be commencing again shortly.”
Who knows what shortly is? With this time line I may need to update my address, or maybe not. I guess that depends on what shortly is?
So much for Christmas. Funny is that you bought it for an early review and even though we are several months into the KS, even if it takes a half year for you to see the meter, you may still be one of the first reviewers. :-DDI thought they would have shipped by now.According to yesterday’s update I guess the shipping information address update request was mostly for people receiving the PCB and switch fix, not for shipping meters to those still waiting. That wasn’t clear on the address update request, so as it stands no ETA on when the meters will resume shipping. Well the official statement is “future shipments which should be commencing again shortly.”
Who know what shortly is? With this time line I may need to update my address before shorty happens? I guess that depends on what shortly is defined as?
Did you have your standards calibrated so we have some known reference?I have capacitor standards, as for the resistors they are just expensive Vishay mill spec low ppm high efficiency new resistors. Even if my lab temperature drifts 3 Celsius they will read the same, but my lab doesn’t drift that much. I already logged the lab temp for 48 hours and it was almost 1 degree Celsius max drift in temperature.
One of the videos I had pulled was comparing the pre-production meter with the 34401 and my BK LCR meter. Dave had said early on that the meter may not have been in cal but I seem to recall it being pretty decent.
OK, watching it now... Wow was it painful to watch it read a 150pf capacitor. I wonder if the new firmware and final hardware is still this slow. Accuracy wise, looks fairly impressive considering this was after I had damaged the meter twice and had modified it. Looking forward to seeing the final version ran.
What about its capabilities in measuring small resistances like 0.1R or so?I have a precision current shunt resistor for ghaynvalie, I think I own two. And I own two 4 wire kelvin miliohm meter to confirm then accuracy. So I plan to see if it can measure that low, and lower with fuses and 100mm strips of nickel since I can easily calculate the knows resistance of nickel from my battery spot welding rig. So I’ll let you know once I get mine.
So for example is the Chinese LCR meter (30$) on Banggood or Aliexpress a better choice for the job than this expensive DMM?
So for example is the Chinese LCR meter (30$) on Banggood or Aliexpress a better choice for the job than this expensive DMM?
Even better, a $5 cheap DMM + a cheap DIY constant current power supply, will make you able to measure sub 1 Ohm quite accurate, as long you understand the principal of 4 wires measurement.
2 wires probe DMM even the expensive one, can NOT measure sub 1 Ohm reliably.
I came to realize that by practice after making 0.15R resistor out of 15 1.5R ones to act as a power resistor. It gets even worse when I connected my multimeter to measure current passing through it, then multimeter internal resistance was added to make the whole measurement unreliable.
I came to realize that by practice after making 0.15R resistor out of 15 1.5R ones to act as a power resistor. It gets even worse when I connected my multimeter to measure current passing through it, then multimeter internal resistance was added to make the whole measurement unreliable.
So if you want a cheap and accurate way to measure miliohms that you can also use to measure internal resistance of batteries with I recommend you try this meter.
battery company that went out of buisness.
maybe to see if you had a user manual.
battery company that went out of buisness.
No company went out of business.maybe to see if you had a user manual.
For example and pure nickel strip best for carrying currents between battery lithium cells from 10 to 15 amps that is 0.15mm thick, by 8mm wide and 100mm long should measure at 6.9 miliohms.
It wouldn't damage any meter with a proper CAT rating.
OTOH it might skew the test results by giving some meters a head start. eg. Nether the Fluke nor the Hioki are showing "0L" at the start of each test.
There's a place that sends you free multimeters? For free?There’s a therapy thread? Please share, my best friend needs multimeter obsession help. :-DD
Don't let that information reach the therapy thread. :scared:
https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/ (https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/)
I found this video where he pulls apart the Yokogawa. Looks like they have some sort of gas tubes. The Gossen used GDT's and held up very well in the transient tests. The Keysight meter I looked at also used GDTs and was damaged early on in the testing.
Does your meter look the same inside as this one?
Thanks for taking the pictures. Looking forward to seeing them.
Looks like I am one of the unlucky ones that only got shipped a replacement knob but no shim ; - ;
Have contacted Dave to try and get the shim re-shipped
I got the switch shim fix and new knob and installed it today. The knob itself is much tighter now, and it seems to have helped the turning off issue I was constantly having near the Ohms and power selection. For a little bit, I was still having the same issue where the multimeter was turning off, but after a little bit of time, it seems to have settled in, and I can't replicate it even with some spirited jiggling.
Looks like I am one of the unlucky ones that only got shipped a replacement knob but no shim ; - ;
Have contacted Dave to try and get the shim re-shipped
I had a fairly long logging session recently that logged DC V while charging a 12V battery. I left it on the default logging rate, thinking that was once per second, but it turns out that my meter defaulted to "0", so according to the manual was actually logging at the fastest rate of around 200ms.
Around 25-26 hours later I went to the meter and saw a voltage of around 13.67V. My victron BMV-712 told me that current down to nothing, so that was as far as the charger was going to take it. I stopped the logging, and the beginnings and end of the log file look like:
START,2018/04/24,16:45:07,
ID,170800000,
INTERVAL,000,sec,
,MAIN,,,SUB-1,,,SUB-2,,,Remark,
No. ,Func. ,Value,Unit,Func. ,Value,Unit,Func. ,Value,Unit,
1,DCV,013.182,V,,,,,,,,
2,DCV,013.188,V,,,,,,,,
3,DCV,013.187,V,,,,,,,,
4,DCV,013.187,V,,,,,,,,
5,DCV,013.187,V,,,,,,,,
6,DCV,013.187,V,,,,,,,,
[cut]
364219,DCV,013.529,V,,,,,,,,
364220,DCV,013.530,V,,,,,,,,
364221,DCV,013.529,V,,,,,,,,
364222,DCV,013.530,V,,,,,,,,
364223,DCV,013.529,V,,,,,,,,
364224,DCV,013.529,V,,,,,,,,
364225,DCV,013.530,V,,,,,,,,
364226,DCV,013.529,V,,,,,,,,
MAX,67374,DCV,013.531,V,
MIN,1,DCV,013.182,V,
Something is very odd here. The last sample was 13.529V, and the max was recorded as 13.531.
I am not sure what happened here. It doesn't help that the meter only logs sample count, and not time. If I really assume that it took a sample every 200ms, then the meter only logged for a little over 20 hours. But I know that I stopped it a minimum of 25 hours later. So, OK, 200ms is approximate. So maybe its is more like every 250ms on average...that would work out to a little over 25 hours (after 364226 samples).
But if it really was logging up until the point that I stopped it, then why were there no records of the 13.67V readings that I saw on the display (and was also reported by the Victron BMV-712)?
I got the switch shim fix and new knob and installed it today. The knob itself is much tighter now, and it seems to have helped the turning off issue I was constantly having near the Ohms and power selection. For a little bit, I was still having the same issue where the multimeter was turning off, but after a little bit of time, it seems to have settled in, and I can't replicate it even with some spirited jiggling.
Maybe there was some form of contaminant on the pads or contacts that eventually wiped away?
I am not sure what happened here. It doesn't help that the meter only logs sample count, and not time. If I really assume that it took a sample every 200ms, then the meter only logged for a little over 20 hours. But I know that I stopped it a minimum of 25 hours later. So, OK, 200ms is approximate. So maybe its is more like every 250ms on average...that would work out to a little over 25 hours (after 364226 samples).
Question...Does the 121GW log counts not time because it lacks a real-time clock? Could some sort of time-stamp be implemented in the log data in future based on the calculated time from sampling frequency? This would really be helpful.RTC is U7. Here's the data sheet.
Yes, I saw 13.67V on the LCD display of the 121GW, and confirmed the value with another device before I ended logging by holding down the MEM button. Both devices agreed fairly closely. In hind sight, I probably should have made note of what the sample counter was doing on the LCD before ending logging.
Just a few questions:
- Did you read the 13.67V on the 121GW or another device (Error potentially in reference)
- Does your 121GW measure 13.5V correctly if simply given DC (Error potentially in calibration)I don't have any reason to believe that particular value is wrong. The calibration reasonably matched a couple of my other meters last time I checked. I'm running a log of a discharge cycle at the moment, but I will double check the calibration after that. UPDATE: Yes, it matches two other meters quite closely measuring 13.5V.
- What version of firmware do you currently have (So I can test against that version)1.10
- Did sample 67374 correlate to the 13.531 V MAX value?Yes, sample 67374 was the first instance of 13.531V in the file.
- What was your charging setup?This is in a travel trailer. A WFCO WF-8735 is charging a Greenlife GL100 LiFePo battery (with built-in BMS to tolerate being used as a lead acid battery drop in replacement, even if it isn't ideal). At the start of the log the WF-8735 is in constant current mode and was delivering just under 36A according to the victron battery monitor (the WF-8735 is rated for 35A, so that is fairly reasonable). The leads of the 121GW are clipped directly to terminals on the battery posts.
Question...Does the 121GW log counts not time because it lacks a real-time clock? Could some sort of time-stamp be implemented in the log data in future based on the calculated time from sampling frequency? This would really be helpful.RTC is U7. Here's the data sheet.
Update has been released to the app stores, likely hasn't updated on both yet but these issues should all be resolved now, we also have a new firmware version which will be resolving one of the other issues (when the voltage in VA mode is above 32767 approximately, this firmware update hasn't been released, this issue was a packet issue not a app issue so for those values you'll need to wait for the next firmware update).
Did any European early birds get the shim sent to them yet? My meter dial has started to play up and I haven't received the shim.I am still waiting for delivery. I recognize the shim problem since about 2 weeks now.
Did any European early birds get the shim sent to them yet? My meter dial has started to play up and I haven't received the shim.I am still waiting for delivery. I recognize the shim problem since about 2 weeks now.
calibrate zero offset but this did not help. The last firmware (v1.15) did not too.
Hi Backers
Sorry for all the delays, but we have been working through various issues that are now sorted out and we are back on track for production.
UEi are ramping back up production and calibration, and have the following dates:
- 50 units are shipping to me on the 5th May (this is an original lot of units that went into limbo at the docks - long story, but we have to account for these separately and some people are aware of these and have asked about them)
- 1000 units will be available for shipping to the various distributors on the 19th May.
(EEVblog for Aus + misc countries, Kane Test for the US, Welectron for the EU)
- Another 1000 units will be available ASAP after that.
Please note that UEi can't magically produce and calibrate thousands of units at once, and especially testing and calibration takes significant time. Current capacity is basically around the 1000 units per month figure.
The first lot of 1050 units will obviously fulfill the remainder Great Scott backers (mostly US based customers), and there will be a large number left over to start fulfilling the Johhny B. Goode backers. But which of these backers will get shipped units first I can't say, as that will depend upon exact number of units available for each distribution center, and likely the order in which you backed. There will unfortunately be a large number of Johnny B/ Goode backers who will have to wait for the next 1000 unit batch.
And please note that the above dates are NOT shipping dates to backers, they are dates when units leave the factory to the distributors. Obviously there will be extra logistical handling delays involved that are unique to each distributor. So please understand that we can't give an exact date your particular unit will be shipped, so please refrain from asking. Rest assured that the wheels are in motion and you will be shipped your unit and receive your tracking number as soon as it ships.
The EU VAT invoices for Johnny B. Goode backers will be going out shortly, and there will be a separate update for this.
I will provide further updates when actual units ship to backers.
Also, for existing backers who have their meter, v1.15 of the firmware has been released with various fixes, please update and use that firmware whenever reporting any issues, we want everyone on the latest version.
As always, the best place to follow progress and discuss things is on the EEVblog forum thread for this, Kickstarter comments is just horribly suited to discussions.
https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/ (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/)
Regards
Dave.
Hey Dave, I am ready for a refund. I was backer #115 for great scott, early bird. I paid in November, 2017. Sorry man, it's just been five months after the promised date. I will have to stick with my Fluke.Now that's odd.. Becoming a backer before becoming a forum member :-//
Now that's odd.. Becoming a backer before becoming a forum member :-//
I was in the original batch of a meters sold through the store, and as such cant see the updates posted to the kick-starter page, is there any way I can see these at all, or an alternate place I can read them.
Dave,
I honestly don’t know if I will need to change my address or not based on the update email, obviously EUI should start shipping the next 1050 units. So if I understand this correctly the first 50 goes to Australia, then the next 1000 remaining EUi sends out goes to different fulfillment shippers based on the addresses in the remaining “great Scott” option? Since the “Great Scott” was only 450 I’m to assuming this supply will cover the remaining “Great Scott” supports on May 19th?
Now the question becomes if I change my address on Kickstarter how fast does this data get to EUI or the shipper like Kane for US customers and refreshed, and then passed onto Kane for the US shipper? Can we get a hard cutoff date to when the last date will be to change the address in Kickstarter?
I can’t give or know a hard date on when my address will change, if your have ever sold a house before then you know things can change at the last minute that will also change the date of the sale.
I don’t know about other country local posts but the US post office will not forward packages. The original shipping method was to be done with DHL as original mentioned in the “Great Scott” package I selected on Kickstarter. But it seems DHL isn’t handling any of these shipments now and was originally changed in the beginning also, that’s my assumption from the beginning logistics that seemed to be changed and was part of the original hold up at US customs.
I think a little more details will help me and others in my situation figure out what steps we might need to make next. For example, I have a UPS, USPS, and FedEx account. If I at least know what shipping carrier Kane will be using and the package is tracking then I may have different options to ensure I get the package without involving the Kickstarter address change.
If Kane is using USPS then my address forwarding will just screw this up. This means I need to do the Kickstarter address update and why the hard date would be useful and hope this change of address gets from Kickstarter, to Dave, then to Kane in time before it ships.
If I know Kane is using UPS for shipping then I don’t have to worry about my USPS post office forwarding and the meter package being returned, or worse case the new owner of my house keeping it. For this reason I hope these are being shipped insured?
I can work with my UPS account once I have a tracking number and request it be delivered to my new address or I can set up a UPS/or FedEx P.O Box. I would have done this already, but we never had a sure date in when shipping would continue and I couldn’t afford paying on a P.O. box since December just for this meter.
I can’t change Kickstarter to a confirmed new address since I have to sell the house first before buying a new one. And I was hoping to take a holiday that I haven’t had in 5 years first for maybe a month before buying a new home so it might go to a UPS P.O. box. Besides I don’t think Kickstarter allows P.O. box shipments anyway.
And same goes for FedEx, I believe I can work with my FedEx account in the same way I would work with my UPS account.
FYI: For others, it’s free to set up an basic UPS, FedEx, and USPS account online. You may need to provide a payment card but it didn’t involve a monthly fee and you don’t need to be a company for these accounts. Well at least it was when I set these up a few years ago.
Can we get a little more details?
1. How many of the “Great Scott” meters were already shipped in the first round. How many of the 450 still need to be shipped? If it will follow backer order and I know mine is in the next 100 from Kane then I’ll just let things be.
2. How is Kane shipping to US customers? Are they using FedEx, USPS, UPS, DHL? Knowing this I can at least put some changes in place with those shippers accounts to ensure it won’t get lost.
3. Will you or Kane be sending out tracking numbers? If I have this and see it’s going to the wrong address I can have the shipper intercept it and change the packages route to the correct destination. This
could happen if a Kickstarter address change doesn’t get filtered to the shipper fast enough.
5. On a scale from 1 to 10, how sure are you on the May 19th start of shipping before I pay for a P.O. Box. But I will still need to know the shipper Kane uses for the best P.O. box to set or put a hold on my packed from that shipper.
Hey Dave, I am ready for a refund. I was backer #115 for great scott, early bird. I paid in November, 2017. Sorry man, it's just been five months after the promised date. I will have to stick with my Fluke.
I got an email saying something from the eevblog store has been shipped, but not what it is or what to do with it
Did any European early birds get the shim sent to them yet? My meter dial has started to play up and I haven't received the shim.I am still waiting for delivery. I recognize the shim problem since about 2 weeks now.
If you are one of the early birds you should have the same version as me. Can you please check something for me?
When I shorten the voltage input to com and set the 121GW to voltage AC 5V range I get a value of about 0,4999V displayed. When I open the short it is nearly the same (a little more maybe 0,5001V). In all other voltage AC or DC ranges I get 0,0xxxV when the input is shortened.
I tried to calibrate zero offset but this did not help. The last firmware (v1.15) did not too.
I got an email saying something from the eevblog store has been shipped, but not what it is or what to do with it
Yep me to. Was it the new knob and shim?
Does each backer get a tracking number sent to them when their meter is dispatched on the final part of the journey?
I was in the original batch of a meters sold through the store, and as such cant see the updates posted to the kick-starter page, is there any way I can see these at all, or an alternate place I can read them.
Sorry, didn't think about that.
I guess I could bulk email those original 50 people?
This thread is the best place for updates really, the Kickstarter updates are more for those who haven't gotten their meter yet.
If you are one of the early birds you should have the same version as me. Can you please check something for me?
When I shorten the voltage input to com and set the 121GW to voltage AC 5V range I get a value of about 0,4999V displayed. When I open the short it is nearly the same (a little more maybe 0,5001V). In all other voltage AC or DC ranges I get 0,0xxxV when the input is shortened.
I tried to calibrate zero offset but this did not help. The last firmware (v1.15) did not too.
Did any European early birds get the shim sent to them yet? My meter dial has started to play up and I haven't received the shim.
10 days to back or take pre-orders on a project is way too low....
10 days to back or take pre-orders on a project is way too low....
And no matter how long I left there will be people still complaining they missed the Kickstarter.
And it's not like I didn't announce it in a video, on this forum, on Twitter, on Facebook, on my blog etc.
10 days to back or take pre-orders on a project is way too low....
Update has been released to the app stores, likely hasn't updated on both yet but these issues should all be resolved now, we also have a new firmware version which will be resolving one of the other issues (when the voltage in VA mode is above 32767 approximately, this firmware update hasn't been released, this issue was a packet issue not a app issue so for those values you'll need to wait for the next firmware update).
Would you please push your app changes to the gitlab repo as I suspect the RangeLookup table in Packet121GW.cs has changed. I'd like to add your changes to my script.
Thanks!
Update has been released to the app stores, likely hasn't updated on both yet but these issues should all be resolved now, we also have a new firmware version which will be resolving one of the other issues (when the voltage in VA mode is above 32767 approximately, this firmware update hasn't been released, this issue was a packet issue not a app issue so for those values you'll need to wait for the next firmware update).
Would you please push your app changes to the gitlab repo as I suspect the RangeLookup table in Packet121GW.cs has changed. I'd like to add your changes to my script.
Thanks!
Hi Seppy,
ping :-)
Is there a chance that you update the gitlab repo?
I'd like to see how you did solve the subdisplay range in [m]VA mode.
The minor issues with firmware should soon be resolved, I'm sure.
Did you really have to break the iOS app with the firmware update?
Did you really have to break the iOS app with the firmware update?
Yes, we did have to, sorry, for reasons of comms integrity.
BTW, the iOS is not "ours", i.e. EEVblog's, it is UEI's app.
I received the new rotary switch and shim for 121GW multimeter.
I took a video of before and after of changing them.
I received the new rotary switch and shim for 121GW multimeter.
I took a video of before and after of changing them.
Yes... do not remove the 4 small silver-capped screws on the top part of the back of the board - these hold the display down and there is no need to remove them or the display. It's a bit of a risk if you do remove the display because murphy's law can come into play. :phew:
I got my packet with the new range switch but no yellow shim. :(Your not the first to report this!
Funally got my knob snd shim, but no instructions. Are they posted somewhere?
http://www.eevblog.com/files/How%20to%20Replace%20121GW%20Rotary%20Switch-180411.pdf (http://www.eevblog.com/files/How%20to%20Replace%20121GW%20Rotary%20Switch-180411.pdf)
12) Make sure that the 3 PTCs are lined up in a row.Just curious, have been cases of bent PTCs or why the note? Simple basic precaution?
I'm an EU JBG backer and I can't see a paypal invoice, not sure if its a PEBKAC or not but everything looks ok on the kickstarter survey, anyone else in the same boat? :-//
Update coming on KS today.
All Great Scott US backers have now been shipped. If anyone in the US can post a photo of the packaging then we'd be curious to see it. Thanks.
Other remaining Great Scott backers also shipped, so that's all of them now :phew:
Update coming on KS today.
All Great Scott US backers have now been shipped. If anyone in the US can post a photo of the packaging then we'd be curious to see it. Thanks.
Other remaining Great Scott backers also shipped, so that's all of them now :phew:
Just for info, I have not received a shipping notification or tracking number. How long should I wait before querying this?
Got my tracking number in the last 5 minutes. FedEx.
Not found
This tracking number cannot be found, please check the number or contact the sender.
Got my tracking number in the last 5 minutes. FedEx.
Just received a fedex tracking number 30 mins ago as well (from 121gwdonotreply@gmail.com)
Fedex can't find it though:Code: [Select]Not found
This tracking number cannot be found, please check the number or contact the sender.
Got my tracking number in the last 5 minutes. FedEx.Ok, so is it safe to say US backers are receiving the meters with FedEx shipping?
Got my FedEx tracking at 7:47a PST.Great (Scott),
Sent from my Moto x4 using Tapatalk
Subject: 121gw trackingGot my FedEx tracking at 7:47a PST.Great (Scott),
Sent from my Moto x4 using Tapatalk
Can you induced anything from the email. Like and first sentence line. Or the email domain it was sent from.
This way other and I can search our inbox for this first sentence to make sure it wasn’t filtered to another folder.
Don’t include you shipping # or any personal information for your privacy.
Thanks,
Scott
Subject: 121gw trackingGot my FedEx tracking at 7:47a PST.Great (Scott),
Sent from my Moto x4 using Tapatalk
Can you induced anything from the email. Like and first sentence line. Or the email domain it was sent from.
This way other and I can search our inbox for this first sentence to make sure it wasn’t filtered to another folder.
Don’t include you shipping # or any personal information for your privacy.
Thanks,
Scott
Sender name: eevblog 121gw
Sender email: 121gwdonotreply@gmail.com
Message body: HELLO YOUR 121GW METER IS SHIPPING VIA FEDEX HERE IS YOUR TRACKING NUMBER:
Sent from my Moto x4 using Tapatalk
I'm in the 100 to 200 range.Subject: 121gw trackingGot my FedEx tracking at 7:47a PST.Great (Scott),
Sent from my Moto x4 using Tapatalk
Can you induced anything from the email. Like and first sentence line. Or the email domain it was sent from.
This way other and I can search our inbox for this first sentence to make sure it wasn’t filtered to another folder.
Don’t include you shipping # or any personal information for your privacy.
Thanks,
Scott
Sender name: eevblog 121gw
Sender email: 121gwdonotreply@gmail.com
Message body: HELLO YOUR 121GW METER IS SHIPPING VIA FEDEX HERE IS YOUR TRACKING NUMBER:
Sent from my Moto x4 using Tapatalk
Thank you, that’s. Great help.
Well I wouldn’t delete an email with that subject, md for search box works with the submit I get Kickstarter update #24, 22, and 21 from April to May. So maybe they are still sending them out.
What backer # are you?
Thanks again,
Scott
Got my tracking number in the last 5 minutes. FedEx.
Just received a fedex tracking number 30 mins ago as well (from 121gwdonotreply@gmail.com)
Fedex can't find it though:Code: [Select]Not found
This tracking number cannot be found, please check the number or contact the sender.
Has to actually be scanned at a FedEx location to show up on their site, you probably got the email when the shipping invoice was created.
@DaveO c'mon Because you don't want to sign up with paypal Dave has to bend in seven ways to give a solution that suits you? Remember that this is already goodwill from Dave. If you don't like it just pay the mailman.
I have indeed received the Paypal note for the EU VAT invoice. (I'm on the Johnny B. Goode batch.) However I can't seem to be able to pay via Paypal; the Australian (not Austrian) version allows me to pay without creating an account (which I of course *do* want), unfortunately after selecting my country and language, I'm taken by the balls and have to create an account... :wtf: screw them, I f*** hate that! :--
Instead I could either pay the VAT by bank transfer (this is the term I'm used to with Digi-Key when not using a credit card), for which I'd need a bank account number (though I might have to pay more but I just don't care) or... I also use to pay the remaining taxes upon delivery to the driver, so if it's a possibility, so be it. Send cash inside an envelope? Why not. Name your price.
And thanks again for this work.
@Dave
I have indeed received the Paypal note for the EU VAT invoice. (I'm on the Johnny B. Goode batch.) However I can't seem to be able to pay via Paypal; the Australian (not Austrian) version allows me to pay without creating an account (which I of course *do* want), unfortunately after selecting my country and language, I'm taken by the balls and have to create an account... :wtf: screw them, I f*** hate that! :--
Instead I could either pay the VAT by bank transfer (this is the term I'm used to with Digi-Key when not using a credit card), for which I'd need a bank account number (though I might have to pay more but I just don't care) or... I also use to pay the remaining taxes upon delivery to the driver, so if it's a possibility, so be it. Send cash inside an envelope? Why not. Name your price.
And thanks again for this work.
O c'mon Because you don't want to sign up with paypal Dave has to bend in seven ways to give a solution that suits you? Remember that this is already goodwill from Dave. If you don't like it just pay the mailman.Where did I write Dave has to "bend"? :palm: Does asking a question imply that the answer is Dave has to... damn'... I don't even follow your logic. If Dave doesn't agree, he can always say "no" which, if you read me again, is part of the (open) option list I gave — damn! why do I have to justify myself in the first place?
If you don't like it just pay the mailman.I suppose you're replying in Dave's behalf, right >:D ?
I'm a Great Scott backer (#260) and just received a e-mail with a tracking number. W00t! Tracking shows that it is shipping from Indianapolis
I received my tracking number today, backer 274 in the US. It say expected deliver Friday, but today is Thursday and the label still states it is only printed I have my doubts for a Friday delivery. Since FedEx doesn’t work on weekends I might see this Monday or Tuesday of next week. Seems that US Kane shipment are going in order of the backing numbers.I'm a Great Scott backer (#260) and just received a e-mail with a tracking number. W00t! Tracking shows that it is shipping from Indianapolis
Also got mine, number 269, with the same details.
I received my tracking number today, backer 274 in the US. It say expected deliver Friday, but today is Thursday and the label still states it is only printed I have my doubts for a Friday delivery. Since FedEx doesn’t work on weekends I might see this Monday or Tuesday of next week. Seems that US Kane shipment are going in order of the backing numbers.
Scott
So did Kane decide to overnight them to try and make up some time on having to hold them and fix the PCB manufacturing mistake?
Having my 121GW since many months now. The issue with the range switch is getting worse. Anxiously awaiting the new range switch and shim. So far no news in my email or normal postal inbox. Any people in Europe received the new range switch and shim? I noticed some German 121GW users on this thread?
Thanks, I was able to confirm ground when I tripped over the box today arround 2pm.So did Kane decide to overnight them to try and make up some time on having to hold them and fix the PCB manufacturing mistake?
No. FedEx Ground. Mine is in the middle of a long road journey and won't arrive until next week.
Got mine today. Just FYI, this meter has the same issue with right angle Probemaster leads that Fluke meters do - the black lead (though it may vary by batch) of my micro-tip leads doesn't quite fit, though I can get it in further than my Fluke 87. AFAIK only the right angle banana plug models do this, the straight ones are fine.
I use the probemasters with the retractable shrouding and don’t have any issues with any of the meters including the 121GW or my Fluke. It also makes it good to be able and use the probes on power supplies in a pinch when you need one more cable since it retracts and they are two years old.Got mine today. Just FYI, this meter has the same issue with right angle Probemaster leads that Fluke meters do - the black lead (though it may vary by batch) of my micro-tip leads doesn't quite fit, though I can get it in further than my Fluke 87. AFAIK only the right angle banana plug models do this, the straight ones are fine.
My 121GW arrived on Thursday via FedEx.
I have tried three different sets of right angle Probemaster probes with no problem.
I too don't have any problems with my probemaster right angle probes on my Fluke, 121GW and any other meter.Yes, I agree. The springs are to long and to soft. If you look at it closely it’s a cheap 4AA battery box they just out into the back of the meter molding. It’s nkt even part of the original molding. I guess this was a cheaper way to go then making the battery box part of the molding?
I had the same problem with the bended springs and the contacts falling out of the case of the battery compoundment. But this can be corrected. The springs I think are to long and the fastening hooks of the contacts are to soft so that they do not hold well in the compound over time after the batteries are in again. Just keep an eye on it when opening the compound.
Took my who day plans out of wack now. I just had to open it.
Scott
Yes, I agree. The springs are too long and too soft.
I would check you batteries, mine were shoved in fast and the negative springs were bent on 3 out of 4 of the batteries. You can remove the battery, bend the spring downwards with a little pressure and put the battery back. Hopefully over some time the spring with restore and retain it intended position.
Hi all,
I arrived really late to this, so I've missed many things and, although I have read the whole thread, I still have doubts about how to get one of this meters. As I understand, the EU distributor is Welectron but, must I contact them for and order or wait instead for the next (if any) kickstarter campaign? Will there be more kickstarter campaigns at all?
Thanks & regards.
new video from Gadget Review VideosJon, thanks for the post.
I mention this because of all the dislikes.
I actually mentioned this in a different thread I think? The springs were folded over and pinched so I did recommend on a post to look at the new meters batteries and try to bend the springs down and put them back into alignment. I know everything is going modular these days but it looks like the back battery molding was separate from the battery case, as if the battery case was a module that was just put into square placeholder on the back molding.I mention this because of all the dislikes.
I'm not sure why there would be so many dislikes. I watched the video and it seemed fine. Some people just like to hate I guess.
You did point out a few issues from your inspection, and maybe that upset people who wanted the meter to be perfect. But that's not your fault, and no reason to dislike the video.
I notice you didn't open the battery cover and look at the battery springs. How did they look, in terms of fit and finish?
I actually mentioned this in a different thread I think? The springs were folded over and pinched so I did recommend on a post to look at the new meters batteries and try to bend the springs down and put them back into alignment. I know everything is going modular these days but it looks like the back battery molding was separate from the battery case, as if the battery case was a module that was just put into square placeholder on the back molding.
Unfortunately I didn’t have a camera rolling when I looked at this. I guess I didn’t expect that with the batteries. Seems like a simple old tech on how batteries are held into something. The only time I’ve had to mod a battery spring was with an LED flashlight build if the battery had a protection circuit, then I had to shorten the spring or replace the spring with a stronger shorter spring for better contact to get full looser to the LED driver. I’ll take a second look and see if the springs bent back or if they stayed after I adjudged them and let out know.I actually mentioned this in a different thread I think? The springs were folded over and pinched so I did recommend on a post to look at the new meters batteries and try to bend the springs down and put them back into alignment. I know everything is going modular these days but it looks like the back battery molding was separate from the battery case, as if the battery case was a module that was just put into square placeholder on the back molding.
I forgot if it was you who mentioned it. I was just curious to see what the battery compartment and springs looked like on video.
If anyone in the US can post a photo of the packaging then we'd be curious to see it. Thanks.
Dave,
I elected to pre-pay the EU VAT but I've still not received any PayPal invoice for it, I've also sent you a message on Kickstarter about this some days ago...
Backer #47 .. Received the meter today, #381.It should be the latest manual. The manual does have a revision date in it. If the date matches close to the date of the latest firmware you can asssum it is. I think it also has a change log as well with dates changed.
It's going to take a while for me to get used to it since my older meters are a lot more primitive. I shall admit that my most-used meter was not auto-ranging.
Since there has been firmware updates, is the manual at http://www.eevblog.com/files/EEVblog-121GW-Manual.pdf (http://www.eevblog.com/files/EEVblog-121GW-Manual.pdf) the most current version of the manual? Mine did not arrive with any manual, only a calibration cert.
looking forward to receiving mine, where can I buy reliable alligator clips for the supplied probes? (if they exists)Franky has these and some more parts including the leads itself from Brymen:
https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm (https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm)
Yes. I believe his brother in law or someone was taking over most of the ebay business.https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm (https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm)
or for US ebay:
https://www.ebay.de/itm/Brymen-Silicone-Gold-Plated-Test-Leads-Probes-for-Multimeters-CAT-IV-1000V/171162377470?hash=item27da129cfe:g:uSQAAOxyTjNShpch (https://www.ebay.de/itm/Brymen-Silicone-Gold-Plated-Test-Leads-Probes-for-Multimeters-CAT-IV-1000V/171162377470?hash=item27da129cfe:g:uSQAAOxyTjNShpch)
Is seller f-t-2000 a forum member ? If so did he (he is in a Dave video) say he was moving to Australia and closing? Sorry for my confusion. I want to put a link to him in my List C because he is a respected seller that many members refer to. (but I always forget thus the list) ?
thanks
Confirmed. His brother-in-law did take over the store, Franky and his family did move to Australia.Yes. I believe his brother in law or someone was taking over most of the ebay business.https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm (https://www.ebay.de/itm/Brymen-Slip-on-Crocodile-Alligator-Clips-for-2mm-Probe-Tip-Gold-Spring-Contacts/171302315753?hash=item27e269e6e9:g:jFUAAOxyeZNTTkUm)
or for US ebay:
https://www.ebay.de/itm/Brymen-Silicone-Gold-Plated-Test-Leads-Probes-for-Multimeters-CAT-IV-1000V/171162377470?hash=item27da129cfe:g:uSQAAOxyTjNShpch (https://www.ebay.de/itm/Brymen-Silicone-Gold-Plated-Test-Leads-Probes-for-Multimeters-CAT-IV-1000V/171162377470?hash=item27da129cfe:g:uSQAAOxyTjNShpch)
Is seller f-t-2000 a forum member ? If so did he (he is in a Dave video) say he was moving to Australia and closing? Sorry for my confusion. I want to put a link to him in my List C because he is a respected seller that many members refer to. (but I always forget thus the list) ?
thanks
https://www.eevblog.com/forum/profile/?u=26834 (https://www.eevblog.com/forum/profile/?u=26834)
His sales thread:
https://www.eevblog.com/forum/buysellwanted/franky_s-sales-thread/ (https://www.eevblog.com/forum/buysellwanted/franky_s-sales-thread/)
Fairly sure the recess is to give room for the raised shaft bore on the contact plate, so so spacer recessed face should face PCB when assembled (away from circlip).I think you may be correct. Mine did still work better, but I also dremeled off those three breakaway mold points as well and just didn’t put this in the video. Dave’s test video does show it backwards, and I saw that video before I realized instruction were available for those who had the switch sent to them.
(https://i.imgur.com/SDNuvbJ.png?1)
borrowed base image from BiOzZ https://imgur.com/a/vHISAb5
Are there any release notes for the firmware updates?
Are the meters supposed to come with a pre-installed microSD card?Yes. Sandisk edge 8gb in mine, but don't know if all the same.
I apologize if I'm complaining too much but my meter is mechanically not super well before and certainly after the shim installation. Too tight to turn the selector knob.Double check which way the shim is facing. Mine came with the shim flipped the wrong way, the knob was way too tight as a result. The recessed face of the shim should face the PCB when assembled (away from retaining ring on the shaft).
So far they have all been 8GB sandisk cards from what others have said.Are the meters supposed to come with a pre-installed microSD card?Yes. Sandisk edge 8gb in mine, but don't know if all the same.
I found that when I took my meter apart the range selection knob had a smooth clicky feel to it, but when assembled with the shim it had a rough, grindy feel that I didn't like.That’s great. I did the same thing. But I used a fine grit polishing dremel bit instead of sand paper. So far so good. I didn’t do any grease yet because I want to see if any dust is created or rubbing is still happening. I feared the grease would collect the dust from any other rubbing parts and it would make it hard to find the rubbing parts. And the grease may thicken if it had dust collected in it. I’ll probably do anther tear down for a quick inspection in a month. But even without the grease it feel like most meters, if not better then some of the meters I own.
I observed that my meter had the same raised molding artifacts that Scottjd pointed out. So I did two things: I smoothed down the raised projections using fine sandpaper, and I applied a small amount of white lithium grease on the contact surface where the shim rubs against the meter back. Upon reassembly my range selection knob now has a smooth, silky and clicky action that it didn't have before.
Can someone do a test on their 121GW to see if it's the same as mine?
1. Put the meter in resistance mode
2. Manually set the range to 0.000 Ω
3. Short the probes (use alligator clips so you don't have to hold them)
4. Expect to see a fluctuating reading in the 0.03 to 0.05 range depending on the probe resistance
5. Press the min/max button to capture the max reading
6. Now lightly touch the HOLD button with your finger and pull it away again (don't press it, just touch it gently)
What does the display capture?
On my meter the reading jumps up dramatically as high as 0.2, 0.3 or even 0.5 Ω
Something similar happens if I press the REL button to null out the probe resistance. Pressing the REL button makes the reading jump high, making it impossible to null out the probe resistance in this range.
Also, occasionally step 4 will show an anomalous reading, for example yesterday the meter showed about 3 ohms. It persistently showed 3 ohms even after turning the meter off and on again and after sweeping the dial through all the other ranges. The shorted probe resistance reading only went back to normal after I put the meter in DC volts and measured a battery. Then suddenly I got the expected 0.035 ohm probe resistance. I have not figured out what event causes the meter to get into this state.I don't think I've seen this one
Yes I'm having this, meter goes way out of spec, 0.5 Ω or more, v1.17. It happens whether max mode is on or not.
6. Now lightly touch the HOLD button with your finger and pull it away again (don't press it, just touch it gently)E field sensitivity perhaps? I've noticed the meter can be relatively sensitive near the LCD display. In fact, the display itself is very sensitive as evidenced by segments activating when pulling away the screen protector. That said, I don't think this meter is abnormally sensitive compared to other meters in its class.
How to make the meter show weird readings:Watch the vid Joe did recently where he's stressing MOV's and PTC's and I think you'll find answers there:
1. Put the meter on the Low Z range
2. Measure the mains voltage (let's say 120.0 V AC)
3. Put the meter on the Resistance range
4. Short the probes
You may observe an anomalous reading of about 3 ohms, slowly declining towards zero.
On other ranges (like DC mV) you may observe anomalous readings too.
It's as if a capacitor is charged up and is taking time to discharge back to zero volts. (Or did something heat up and it's taking time to cool down?)
6. Now lightly touch the HOLD button with your finger and pull it away again (don't press it, just touch it gently)I just did a quick replication of this behavior for the resistance mode. I get no sensitivity on the Peak and Setup buttons, a little sensitivity on the Rel and Mem buttons, and high sensitivity on the Range, Hold, Mode, and Min/Max buttons around the magnitude you described.
What does the display capture?
On my meter the reading jumps up dramatically as high as 0.2, 0.3 or even 0.5 Ω
Something similar happens if I press the REL button to null out the probe resistance. Pressing the REL button makes the reading jump high, making it impossible to null out the probe resistance in this range.
How to make the meter show weird readings:I just tried and does same on mine.
1. Put the meter on the Low Z range
2. Measure the mains voltage (let's say 120.0 V AC)
3. Put the meter on the Resistance range
4. Short the probes
You may observe an anomalous reading of about 3 ohms, slowly declining towards zero.
On other ranges (like DC mV) you may observe anomalous readings too.
It's as if a capacitor is charged up and is taking time to discharge back to zero volts. (Or did something heat up and it's taking time to cool down?)
a little sensitivity on the Rel and Mem buttons
Doing LowZ measurement on mains power you stress the PTC that warms up and so the readings need to settle until the PTC has cooled down to normal temperature again. Until this is done you will get wrong ohms readings.
As tautech already wrote watch Joe's video and you will unterstand why this and what happens.
Doing LowZ measurement on mains power you stress the PTC that warms up and so the readings need to settle until the PTC has cooled down to normal temperature again. Until this is done you will get wrong ohms readings.
I got mine on 17th May in Germany. And I got an email 4 weeks before that it was sent to me.
I've been travelling overseas, but now I am back in the lab earlier this week I finally upgraded my 121GW firmware and installed the shim on the selection knob.
Today I went to measure a 12V DC source and the meter displayed 166V. :scared: Then it decided to show OFL, even when measuring a 9V battery!
My initial thought was I had accidentally manually selected a low range, or it was in mV mode, or I stuffed up in alignment of the knob position during reassembly. But the display matched the various selected range positions. I took the meter apart and couldn't see any issue... until I removed the range selection switch... and the below image is what I found :wtf:
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=445876;image)
I have not been measuring any mains or other high voltages on the meter. The only thing that comes to mind is that the 12V I was measuring was at the input to a couple of POL DC/DC converters which was at the end of a long cable, and the DC/DC converters only had ceramic caps. The DC/DC converter (my own design using TPS54622) is rated at 5.2V 6A out but was struggling to power a Raspberry Pi & pocket 3G router. Measured with another (Tenma or EEVblog/Brymen) meter I was seeing only about 3.8V instead of the expected 5.2V.
I added a 330uF electrolytic capacitor at the input to each of two the DC/DC converters and it solved the problem, so I guess with the long cable from PSU to the ceramic caps was creating a nasty LC circuit and maybe causing some voltage spikes. The cable was ~3m of 18AWG figure 8 speaker cable to simulate what was on-site, and it did help to clearly identify the equipment issue I was tracking down.
No (obvious) damage to the DC/DC converters, Raspberry Pi, or connected equipment, but apparently the meter didn't like it. Or the meter came to me this way as I've hardly used it apart from measuring low voltages mostly out of my sig gen. I doubt that as I'm sure I would have noticed this measurement issue in previous testing.
It was late when this happened and I haven't done further inspection or tried cleaning the PCB yet.
Any thoughts?
Any thoughts?
Do you remember what jacks were in use when measuring the DC/DC?The probes were definitely in the V and COM jacks for voltage measurement, and meter in auto ranging DC V.
Were you using the meter for measurement of current, power or voltage?
The energy to do that couldn't have come via the V jack, there is at least a PTC + 1K in series with every path. Even if the contacts shorted the VA range contacts and the ohms contacts, worst case path is V jack to GND via a PTC + 1K. So, it's weird :-//Agreed, that's basically what I thought - the protections circuits (even if not quite up to Joes standards...) shouldn't have allowed this.
So I can only presume the path is via the low impedance A jack somehow...
Maybe one of the range switch contacts wasn't installed properly and was floating around? I presume you hadn't taken off the range switch before?, as that's required for the shim replacement.
Kean, can you post a photo of the range switch contacts please.Sure, see attached photo. They look squeaky clean to me. Sorry for the potato cam photos - best I can do at 4AM after a couple of rather awful days... but I'm happy to arrange a meet up with you for a closer look and some forensics.
Edit: you can probably work out the orientation of the range switch based on the contamination shown on the plastic underside. You can see the carbon deposit is not near any of the contacts points.To me, it looks like switch would have been in V, or possibly completing a switch between mv and V (closer to V)
Also, note that a while back another member had posted some good pictures of their switch showing a fair amount of contamination in this same area. I am not sure why it would accumulate here.If it was this one https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1561861/#msg1561861 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg1561861/#msg1561861) it don't think it's related (the contamination plastic and possibly some mask as the unit was shipped with switch shim washer installed upside down, causing switch to rub against pcb).
Do you remember what jacks were in use when measuring the DC/DC?The probes were definitely in the V and COM jacks for voltage measurement, and meter in auto ranging DC V.
Were you using the meter for measurement of current, power or voltage?
Sure, see attached photo. They look squeaky clean to me.
So you weren't measuring Power (VA) at all?Nope, don't think I've even tried the VA mode as yet.
I'm now at a loss as to how this happened. Need to think some more...Indeed. Here is a couple of close ups of the PCB - one with backlighting. You can actually see some minor damage to the gold plating in the corners, so maybe there was an arc across those (36&37) but via what path?
IMO, the weak link of the meter's front end is that 15V diode check mode. I marked the switch to make it easy to follow on the schematic.
Also, note that a while back another member had posted some good pictures of their switch showing a fair amount of contamination in this same area. I am not sure why it would accumulate here.
A bit of damage for a low energy source. Is there more to this story??
From Joe's annotation if you measure what is labeled 37 and 15 you get an open circuit, on the schematic these should be a short.
Whereas if you measure between 12 and 36 it is a closed circuit indicating these rows are swapped.
Attached are what I believe the connections to be.
I'm not so sure about the internal trace now, but you can see there is one that goes directly under that crater.
Can someone explain how to display the burden voltage when measuring current?
I can follow the instructions by pressing the SETUP button and changing the setting to "bd.on", but after that I cannot see how to get a voltage shown on the display? (I assume the voltage should appear in the secondary display above the current reading?)
Any thoughts?
The energy to do that couldn't have come via the V jack, there is at least a PTC + 1K in series with every path. Even if the contacts shorted the VA range contacts and the ohms contacts, worst case path is V jack to GND via a PTC + 1K. So, it's weird :-//
So I can only presume the path is via the low impedance A jack somehow...
Maybe one of the range switch contacts wasn't installed properly and was floating around? I presume you hadn't taken off the range switch before?, as that's required for the shim replacement.
Any thoughts?
The energy to do that couldn't have come via the V jack, there is at least a PTC + 1K in series with every path. Even if the contacts shorted the VA range contacts and the ohms contacts, worst case path is V jack to GND via a PTC + 1K. So, it's weird :-//
So I can only presume the path is via the low impedance A jack somehow...
Maybe one of the range switch contacts wasn't installed properly and was floating around? I presume you hadn't taken off the range switch before?, as that's required for the shim replacement.
At 600V 2.5Kohm would still be 250mA. Maybe enough to cook the PCB. Seems possible.
It looks like your DC supply is good for about 10mA. You could try to turn it up to 600V with the 121GW set to the DCV mode, then turn it to ohms. You may not have enough current to damage it, if your goal was to replicate the damage.
My goal was only to show that the contacts do not arc over at these voltages.
Please take a few pictures of R82 and U9 under the microscope. Maybe even ohm out R82. What ever went though these two traces had to go through more parts. There should be some pretty good damage to the top side as well.R82 measures fine (100.3ohm), and no visible damage in the U9/R82 area. In fact no visible damage anywhere else on the PCB, although I haven't looked under the LCD assembly. The fuses are intact.
And here is the photo I meant to attach to that post.Please take a few pictures of R82 and U9 under the microscope. Maybe even ohm out R82. What ever went though these two traces had to go through more parts. There should be some pretty good damage to the top side as well.R82 measures fine (100.3ohm), and no visible damage in the U9/R82 area. In fact no visible damage anywhere else on the PCB, although I haven't looked under the LCD assembly. The fuses are intact.
I also checked with my colleague, and he hasn't use this meter at all. I will reassemble it and run some functional tests shortly, but don't want to do too much before I meet up with Dave.
My goal was only to show that the contacts do not arc over at these voltages.
Yes, but the important factor is turning the selection knob while the voltage is connected. Under these conditions the contact springs can partially bridge the gap between traces on the circuit board and increase the chance of an arc occurring. That's exactly the test Joe was doing in his videos.
Is it allowed that you turn the knob when voltage is connected? But this could be a problem in combination with the lose knob without the shim.
Dave & other interested parties...
I have now remembered a time in the last few weeks I was measuring the 1200V AC output from a 100W Ultrasonic Transducer driver. At the time I was pretty sure I only used my 15kV and differential oscilloscope probes - but based on the damage and Joe Smiths excellent test video, it seems likely that I must have tried to measure the voltage with the 121GW.
Very embarrasing, as I should gave known better!
Amazingly the meter still seems to function perfectly after cleaning the burnt area, and appears to still be in spec against my Keysight 34465A.
Dave & other interested parties...
I have now remembered a time in the last few weeks I was measuring the 1200V AC output from a 100W Ultrasonic Transducer driver. At the time I was pretty sure I only used my 15kV and differential oscilloscope probes - but based on the damage and Joe Smiths excellent test video, it seems likely that I must have tried to measure the voltage with the 121GW.
Very embarrasing, as I should gave known better!
Amazingly the meter still seems to function perfectly after cleaning the burnt area, and appears to still be in spec against my Keysight 34465A.
:phew:
Glad to see it still works (all functions?)
OK, I just ran through a reasonably comprehensive functional test of my "damaged" 121GW, and it all tested out perfectly, even BT. The only mode that I didn't test (and haven't used) is the VA ranges.
I used an Advantest R6142 programmable voltage & current generator, an ITECH IT7321 programmable AC source, some resistance & capacitance decade boxes, a function generator, and some random diodes to hand.
Ok just checked on my iPhone 5s. Logging “save” button works fine there. But still no joy on the iPad mini.
Seems like a bunch of posts above just disappeared?I split the topic so that we can keep app beta testing separate from discussion, only a few testers around :)
I split the topic so that we can keep app beta testing separate from discussion, only a few testers around :)
I split the topic so that we can keep app beta testing separate from discussion, only a few testers around :)
OK, can you then move Reply #910 above to the other thread?
Got mine today, working great. Only problem is that someone on the production line was a bit too much in the spirit of "don't turn it on, take it apart" because it is missing the screws from the back cover :-//
Got mine today ;D. Good job, Dave :-+
Can someone tell me how do I open the battery cover though? I have removed the two screws at the back but the cover just won’t come off. Which direction shall I push/ lift? I don’t want to break anything this soon :-[ Thanks!
Oh...got it :-+. But mine was kind of tight. ;D
https://youtu.be/nL7wDFNH8hM
Got mine today ;D. Good job, Dave :-+
Can someone tell me how do I open the battery cover though? I have removed the two screws at the back but the cover just won’t come off. Which direction shall I push/ lift? I don’t want to break anything this soon :-[ Thanks!
Oh...got it :-+. But mine was kind of tight. ;D
Not read through all the posts to check if this has been discussed (and AFAICS the forum can't search a single thread), but it isn;t mentioned in the manual
I notice that the mode setting is retained after power-off. Although this can be useful it can also be annoying, especially if the meter isn't used often. It would also be a pain for a meter that was shared by several users, or used by someone unfamiliar with it.
AFAICS there is no option to make it always power up in a consistent mode - I think this would be a useful addition.
Apropos of nothing, either both of these meters are correct, or both of them are wrong: :)
Not read through all the posts to check if this has been discussed (and AFAICS the forum can't search a single thread), ...
We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.Could you not add a simulated device in the app that generates a slow sine wave or something. Then you can just generate a nice screen shot via the iOS simulator, and people still waiting for the 121GW can start playing with the app. ;D
We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.Could you not add a simulated device in the app that generates a slow sine wave or something. Then you can just generate a nice screen shot via the iOS simulator, and people still waiting for the 121GW can start playing with the app. ;D
I have to admit I've not submitted a screen shot at that resolution in the past - maybe it isn't/wasn't mandatory.
It would be more accurate and honest getting a real screen shot. I also am also not entirely sure it works on iPad Pro, wouldn't want to make it look like it did if it didn't.
We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.
I have an iPad Pro 12.9 inch. (And a 121GW obviously. :) ) Let me know if I can help.
We need a beta tester with an iPad Pro or an iPad with a resolution of 2732 x 2048. We need a few screen shots in that size for the App Store, its part of the submission process.
I have an iPad Pro 12.9 inch. (And a 121GW obviously. :) ) Let me know if I can help.
Ben
is there any news about the EU backer (Johnny B. Goode) shipment? Has someone received the meter or at least the tracking number?
is there any news about the EU backer (Johnny B. Goode) shipment? Has someone received the meter or at least the tracking number?
UK arrived yesterday
is there any news about the EU backer (Johnny B. Goode) shipment? Has someone received the meter or at least the tracking number?
UK arrived yesterday
Was your meter shipped through Welectron (Germany) or shipped directly from Daveland?
Alexander.
I’d be interested to know how much people paid in advance. Very impressed with DHL collecting at 6pm on Friday in Australia and delivering at 1pm on Monday in the UK!That is indeed quick - mine took longer to cross the ditch to NZ!
I was expecting UK taxes+fees to end up at least twice that (~30 GBP in VAT alone) - how did they manage to calculate only 22 GBP inc fees?
I got my meter shipped to family in NZ (planned to pick it up personally in April, but the delay ruined that idea), would have gone the UK route had I known the charges would be that low!
I’d be interested to know how much people paid in advance.I paid £32.77 ($56.05AUD) in advance, now I am waiting for the meter to be shipped to me.
I had elected not to Pay VAT etc in advance and take my chances (I'm Scottish!). I got the DHL request to pay 22 UKP also, I paid it, and the 121GW departed DHL-Sydney today and is now on it's way. Will be here in UK 2nd July.
Hmmm, maybe there will be more to pay once it hits the UK.....dunno!
Ian.
Any news from Welectron? Did they received any meter yet?
Alexander.
EU backers, sorry but your units will be delayed a bit because of production volume. They plan to finish production on 22nd June. After that the units will be shipped to Welectron in Germany for distribution. So hopefully shipping will be in June.
Has it been announced that production and sales of these will continue once all of these initial (quite late) shipments are made? I got to the party a bit too late to participate in the Kickstarter campaign(s), and am extremely interested in purchasing one when (or if?) they are made be available for regular sale.
When is the question - and I'm sure Dave has been thinking about that. I suspect he will be looking for a fairly stable product before venturing further.
Patience is key.
Does anyone know if they used lead or lead free on the jacks?
Ugh, not Duracell :-[
https://www.eevblog.com/forum/testgear/leaking-alkaline-batteries-and-expensive-equipment-a-rogues-gallery/msg1471555/#msg1471555 (https://www.eevblog.com/forum/testgear/leaking-alkaline-batteries-and-expensive-equipment-a-rogues-gallery/msg1471555/#msg1471555)
Look carefully at that picture I posted and use at your own risk.
Has anyone tried the Energizer Ultimate Lithium cells in it yet?
I’m backer #2235 and I was surprised by the meter showing up on my doorstep today!
No shipping notification...
I immediately replaced the 'as shipped' batteries with Energizer Ultimate Lithium.
Works just fine.
I’m backer #2235 and I was surprised by the meter showing up on my doorstep today!
No shipping notification...
Strange how some people are reporting not getting the tracking email. Spam box?
Germany (Munich)
DHL tried to deliver my meter just now.
(Sadly I mooved out of that flat (yesterday...) ;-) ... so now it is at the post-office.)
Backer 2269..Germany
just received a tracking number from DHL (Welectron), the multimeter will be delivered on Thursday. Super-fast processing time from Welectron, super done.. :-+ :-+ :-+
When delivered by DHL normally you should be able to give an advice online where to deliver if you cannot personally accept the parcel.
WTF ? :palm:Your meter was shipped yesterday, but we had to do a second label for your shipment due to the need of a customs declaration to Andorra. Let me know if you did not receive the valid tracking number yet.
WTF ? :palm:Your meter was shipped yesterday, but we had to do a second label for your shipment due to the need of a customs declaration to Andorra. Let me know if you did not receive the valid tracking number yet.
@All: The last batch of 121GW landed a few minutes ago. All backers that have not been served from the first batch will be shipped today.
The 1 MOhm range is quite noisy, and 10 MOhm is way off:
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=478841;image)
It has a 5 MOhm and 50 MOhm range. According to the manual, the 50 MOhm range has a +/-1.2% accuracy. Looks like your meter has a +1.9% error in this range. I wouldn't say that's way off, but technically you are right, looks like it doesn't meet the specification.
Bruchsal, Germany.
The international shipment has been processed in the parcel center of origin
For the rest of you (waiting from Welectron), do you see the parcel being processed daily? Mine is atCode: [Select]Bruchsal, Germany.
The international shipment has been processed in the parcel center of origin
Since Wednesday.
For the rest of you (waiting from Welectron), do you see the parcel being processed daily? Mine is at
For the rest of you (waiting from Welectron), do you see the parcel being processed daily? Mine is atCode: [Select]Bruchsal, Germany.
The international shipment has been processed in the parcel center of origin
Since Wednesday.
yes
(https://i.gyazo.com/22fc63ff958e298e717e9dedc359f68c.png)
That's moved more than mine
(https://i.imgur.com/3y6ynUV.png)
mine is "out for delivery" with DHL express
mine is "out for delivery" with DHL express
Yours was sent with DHL express?
That's both a bad indicator, that there is something fishy.. others also already reported about that instability of these Ohm ranges.
I've never heard of bandguarding ratio and a few Google searches also turn up nothing.
[Edit] From the context it sounds like either Test Accuracy Ratio or Test Uncertainty Ratio (found on a metrological page)
Auto-range broken on V1.22Better move that to the 121 issues thread in the same subforum
At work I'm measuring resistance and the auto-range cycles for ever. If I remember correctly there was an issue with this in the past and it was fixed with firmware change
In my case there is a capacitor that gets charged when measuring resistance. I did the same test with a Fluke in auto-range with no problem
Any comments ?
David DLC
I'm doing some tests and i have some trouble with the uA range.The maximum allowed in the uA position is 500uA so should indicate OFL. It takes a second to show. Fuse should have continuity. Does probe in mA/uA socket, switch in ma work?
I set up a basic led circuit and measured the current on the mA range and the probe inserted into the A/500mA socket, the led is powered on and i measured 9mA.
I switched the range into the uA range and the probe into the mA/uA socket but the led does not power on and nothing is measured on the meter. I checked the 400mA fuse and there is no continuity... fuse blown?? I think that this range should measure 9mA..
Here we go,
I have compiled the basic accuracy verification, (comma used for the decimal point.)
(https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/?action=dlattach;attach=480269;image)
All ranges are very well inside the (barn door wide) specification, mostly a factor of 10 more accurate than specified.
The linearity of the A/D_1 is quite good, but it shows a very pronounced Rollover Error of about36 digits. I've expressed these both characteristics commonly by the overall DNL, Differential Non Linearity, over the nominal +/- 5.0000 V range, which computes to 2 digits, which is quite OK.
(https://www.eevblog.com/forum/index.php?action=dlattach;topic=101816.0;attach=480275;image)
Only the 500k, 5M and 50M Ohm ranges show a strange behavior.
500k and 5M might be quite jumpy all of a sudden, or rock stable the other instance, always with the same physical setup.
The accuracy changes from one day to the other, or from one power-on to the other.
Latter goes also for the 50M range, which integrates much slower; 2 days ago it was out of specification, as it was today morning, but in the afternoon, it was inside spec, but varying from one power-on to the other.
Seems to me, that some internal interference occurs, as if the firmware creates spurious interrupts which affect the readings.
I monitored these different behaviors and will report elsewhere.
Otherwise, that instrument seems to be of very good quality, but not so well specified or qualified by UEI.
I think, that it performs much better, in the same league like other, more expensive DMMs.
Frank
We have tested 10 units now all within spec for 10 M, is there any chance environmental noise made the measurement wobbly? We can test more, but it is going to take some time.
I'm doing some tests and i have some trouble with the uA range.The maximum allowed in the uA position is 500uA so should indicate OFL. It takes a second to show. Fuse should have continuity. Does probe in mA/uA socket, switch in ma work?
I set up a basic led circuit and measured the current on the mA range and the probe inserted into the A/500mA socket, the led is powered on and i measured 9mA.
I switched the range into the uA range and the probe into the mA/uA socket but the led does not power on and nothing is measured on the meter. I checked the 400mA fuse and there is no continuity... fuse blown?? I think that this range should measure 9mA..
Finding the maximum range for each position is a little problematic. The chart on page 16 of manual is useful if available. The auto range position doesn't indicate the max just the current auto range.
So you have to:
1. With probes not hooked up but inserted into desired sockets (required for current)
2. Rotate switch as desired.
3. Select mode.
4. Press range and note the max range value in the lower right corner of display. Continue pressing range until you find the max.
I don't think this is much different than other meters but the text for the value is so miniature I can't even see it without my glasses. On other meters it is much more prominent.
Backer 795 in Sweden just received SENDUNGSBENACHRICHTIGUNG from DHL.Delivered to my door a couple of minutes ago.
I'm doing some tests and i have some trouble with the uA range.The maximum allowed in the uA position is 500uA so should indicate OFL. It takes a second to show. Fuse should have continuity. Does probe in mA/uA socket, switch in ma work?
I set up a basic led circuit and measured the current on the mA range and the probe inserted into the A/500mA socket, the led is powered on and i measured 9mA.
I switched the range into the uA range and the probe into the mA/uA socket but the led does not power on and nothing is measured on the meter. I checked the 400mA fuse and there is no continuity... fuse blown?? I think that this range should measure 9mA..
Finding the maximum range for each position is a little problematic. The chart on page 16 of manual is useful if available. The auto range position doesn't indicate the max just the current auto range.
So you have to:
1. With probes not hooked up but inserted into desired sockets (required for current)
2. Rotate switch as desired.
3. Select mode.
4. Press range and note the max range value in the lower right corner of display. Continue pressing range until you find the max.
I don't think this is much different than other meters but the text for the value is so miniature I can't even see it without my glasses. On other meters it is much more prominent.
Thanks for your help.
no, with the probe in mA/uA socket and the switch in mA range is not working. for sure the fuse is blown. i'm looking for a replacement.
thanks for all the tips!
That's moved more than mine
(https://i.imgur.com/3y6ynUV.png)
(https://i.imgur.com/RbTv7PB.jpg)
My meter finally arrived today and although I have yet to use it in a real situation here are a couple of observations/thoughts about the meter and android app (I don't have any Apple devices so can't say if they are the same or not):
1. The blue tooth and 1Khz filter are below their respective buttons whereas everything else is above, until I read the manual I thought that they were controlled by the buttons below them not above. We might be able to fix that, would take a while though.
2. When connected by blue tooth to the app and you cycle through the "setup" menu you get the setup values showing on the secondary display of the phone - is it possible to put a bit more detail on the phone screen e.g. "Year 2018" instead of "18", "Buzzer Off" instead of "0v" etc.
3. With the meter in setup mode "b-OFF", "Meter ID" and Logging Interval it shows it as a voltage in the app.
4. With the meter in setup mode month and day "07-23" it shows it as 1815 in the app
5. With the meter in setup mode hour and minutes "18-00" it shows it as 4412 in the app
6. In the user manual section "Setup Menu" on page 57 you are missing the "Buzzer On/Off" which should be between "Auto Power Off" and "LCD Contrast"
7. In the buzzer option of the setup menu maybe change it to say "buz.on" and "buz.of" instead of "b-on" and "b-off" - it might be a clearer what the menu item is then without having to consult the manual.
I know that some of these may not be easy or possible to change but thought that you might appreciate some more feedback.
Wow its far more compact than I was imagining and may well end up joining my everyday carry in the tool box.
Now I just need to find the time to use it on a project (I have several in mind if i get the chance).
Jem
Edit: added point 7
adapted to like reading every 50 ms ?
adapted to like reading every 50 ms ?
But can a temp probe be so fast? I thought they have some (thermal) inertia...
adapted to like reading every 50 ms ?
But can a temp probe be so fast? I thought they have some (thermal) inertia...
Thats a good point - anyway is there a way to change the reading interval ?
A thermocouple has very low mass, and therefore reacts extremely fast.. probably even faster than 50 ms.
The problem here, is that the 121GW (or any other handheld DMM) has a fastests sample rate of 200ms, or 5 Sa. /sec, as specified for DC V, afaik.
I just tried a couple of 10 MΩ resistors, which read 10.x MΩ on my BM869s, but they read 9.6 MΩ on my 121GW. (Connection made with alligator clips to ensure a stable connection.)
(Also, I have to note that the auto-ranging would first show a value of 14 MΩ for a second before updating to 9.6 MΩ. I really think the auto-range in resistance on the latest firmware is not right.)
Is it possible that disassembly of the meter to install/check the shim might cause accuracy problems from contamination of the circuit board?
One thing I don;t like is that it doesn't default to the main function of the knob position. It remember the last mode it was.That is a very nice feature.
One thing I don;t like is that it doesn't default to the main function of the knob position. It remember the last mode it was.That is a very nice feature.
I am planning to use it to include as a screen capture along with screen captures from the DS1054Z while testing various cheap ebay buck converters which I will then upload to youtube.
Can I download the Windows software for the 121GW without having to jump thru the microsoft hoops. After logging in with my Microsoft account it now wants me to Add a Device, and seems only Windows 10 is supported. This seems out of character for EEVBLOG. Dave himself hates having to create accounts just to try some software to get a widget to work.
I am planning to use it to include as a screen capture along with screen captures from the DS1054Z while testing various cheap ebay buck converters which I will then upload to youtube.
I have the android app which works ok.
Any direct links or suggestions on how to get the Windows software without the hoop jumping would be very much appreciated.
I am planning to use it to include as a screen capture along with screen captures from the DS1054Z while testing various cheap ebay buck converters which I will then upload to youtube.
What is your YT channel?
thanks
How to measure "burden voltage"?
How to measure "burden voltage"?
On page 40 of the GW121 manual is decribed that you could measure the burden voltage in mA current mode.
I was able to set the "bd.off" to "bd.on", but how will I get the burden voltage to be shown in the secondary display?
I´m using the latest FW 1.22 and the only thing is that I can roll through all the setup parameters with the "setup" button, but I´m not able to show the burden voltage on the display...
For sure I was connecting the additional cable like shown to measure current and (burden) voltage simultaneously.
What´s my problem? PEBCAC?
I'm doing some tests and i have some trouble with the uA range.The maximum allowed in the uA position is 500uA so should indicate OFL. It takes a second to show. Fuse should have continuity. Does probe in mA/uA socket, switch in ma work?
I set up a basic led circuit and measured the current on the mA range and the probe inserted into the A/500mA socket, the led is powered on and i measured 9mA.
I switched the range into the uA range and the probe into the mA/uA socket but the led does not power on and nothing is measured on the meter. I checked the 400mA fuse and there is no continuity... fuse blown?? I think that this range should measure 9mA..
Finding the maximum range for each position is a little problematic. The chart on page 16 of manual is useful if available. The auto range position doesn't indicate the max just the current auto range.
So you have to:
1. With probes not hooked up but inserted into desired sockets (required for current)
2. Rotate switch as desired.
3. Select mode.
4. Press range and note the max range value in the lower right corner of display. Continue pressing range until you find the max.
I don't think this is much different than other meters but the text for the value is so miniature I can't even see it without my glasses. On other meters it is much more prominent.
Thanks for your help.
no, with the probe in mA/uA socket and the switch in mA range is not working. for sure the fuse is blown. i'm looking for a replacement.
thanks for all the tips!
Some 45 years back, the physics lab manager asked us to set all
multimeters after use to a 220 V AC compatible range setting. :-+
Something I still do today automatically after using any DMM anywhere,
if possible.
Happy to read your feedback here. :-+Thanks for pointing that out! Too bad this information got to me too late (I've followed Daves "limited amount of meters in stock" e-mail and ordered directly from him.) The meter is sitting in Frankfurt right now...
As the official EEVBlog distributor, we now also have the 121GW available for purchase in Europe:
https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth (https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth)
My review of the meter: https://lygte-info.dk/review/DMMEEVBlog%20121GW%20UK.htmlInteresting review, I found the input impedance measurements especially surprising. The fact that the meter has different input impedances in different mode and ranges would make it incompatible with high-voltage probes etc. that rely on having exactly 10 MOhm for voltage division.
Having an input impedance as low as ca 2 kOhm for frequency measurement makes limiting for many things. For example measuring the frequency at different points of a 555 timer (or other oscillator) circuit without knowing about the low impedance could result in many strange readings (different frequency at different points, since the meter would affect the circuit by a lot).
Is there any uncertainty? Something you can't take into account while measuring?
I have reported https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1687298/#msg1687298. (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1687298/#msg1687298.) that the 50MOhm range of my new 121GW was out of specification, by 1.4 ..2%.
Today, I have re-adjusted this range.
At first, the manual was wrong, as a 50 MOhm reference resistor is required, instead of a 40 MOhm one.
Then, due to higher leakage currents over protection diodes at 50 MOhm, compared to 10 or 20 MOhm, this range is quite non-linear, like I have found with my BM869.
So the readings at 10M and 19M are about 0.2% higher than nominal, when the 121GW is correctly calibrated at 50.000MOhm.
To compensate for this effect, it makes sense to use a 50.05 MOhm reference instead, so that at 50MOhm, the nominal reading is 0.1% low, but at lower values, like 10MOhm, the reading is only 0.1% high.
So the 50MOhm range is now very precise and stable, and also is not affected by mains disturbances.
The 5MOhm range though, is noisy, due to lacking 50/60Hz suppression, and probably a missing filter capacitor.
I could silence this range, even with strong interference from mains, by a parallel low leakage foil capacitor, 100nF, MKP.
I still hope for FW change by UEI, to correct both features.
Frank
Dr Frank, if you have a way to run some sort of temperature study on this meter, I would be very interested in seeing you install TPW_rules's patched version of 1.02 and trying it out. The prototype has always drifted pretty badly which I assume is why they changed the reference circuit. It sounds like you are already trying to find the sweet spots to use for the alignment to bring it in tighter. I wonder how the TC matches what is specified in the manual.
I just received tracking info for mine, and am about to leave on vacation for 2 weeks >_<Ended up being lucky XD
Anyone got an idea how to arrange this with DHL, or will it just end up going back to sender, and i'll have to arrange a next shipment?
A bit impractical to just send them out in the middle of holiday season without asking if people can receive it
FYI, Welectron in Germany have some meters in stock:
https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth (https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth)
Good for you! Mine is still in Frankfurt since August 1 "Arrived at transit facility"FYI, Welectron in Germany have some meters in stock:
https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth (https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth)
I ordered one from Welectron.Good that there are suppliers wihin the European trade zone.
I received shipping notification yesterday.
The most sensitive part appears to be the HY3131 itself. I'm not making the part even warm enough to detect the change in temp with my fingers.
To be clear, I do not have the current version of the meter. Any idea how much "way off" is and what modes? Could you post some details?
Are you maybe heating up a PTC? What range(s) and how long until things go back to normal?
How to make the meter show weird readings:
1. Put the meter on the Low Z range
2. Measure the mains voltage (let's say 120.0 V AC)
3. Put the meter on the Resistance range
4. Short the probes
You may observe an anomalous reading of about 3 ohms, slowly declining towards zero.
On other ranges (like DC mV) you may observe anomalous readings too.
It's as if a capacitor is charged up and is taking time to discharge back to zero volts. (Or did something heat up and it's taking time to cool down?)
It arrived today. I ordered the 4th from Welectron. I received a first notification from the post services on the 6th, arrived in Belgium the 8th and at my door the 10th.Good for you! Mine is still in Frankfurt since August 1 "Arrived at transit facility"FYI, Welectron in Germany have some meters in stock:
https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth (https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth)
I ordered one from Welectron.Good that there are suppliers wihin the European trade zone.
I received shipping notification yesterday.
Just a note for Dave or David:
The review section on the products page for this meter is starting to attract spam. You might want to take measures to prevent these (I'm not sure if email confirmation is required), or do some moderation.
A video testing the 50 ohm range at low values:
I think the meters were meant to come with the Brymen leads that have the banana plug adapters, but due to a shortage of supply some meters were shipped with leads from another vendor. You would have to search back through the thread history to find the post where Dave mentioned that.
NOTE: The meter may come with either Brymen (gold) probes or UEI (nickel) probes depending upon availability at the time. Both are high quality silicone rubber probes.Source: https://www.eevblog.com/product/121gw/
Anyway, I'm wondering if my test leads should've come with some "tip addons".
The leads shown in the image posted above are definitely the ATL57 silicone series which are identifiable by the ridiculously long strain relief, the ATL55 series have a shorter strain relief.UEI uses the same picture for both on their website so you cannot belief what you see. When you open the data sheet you get a pdf where they use the exact same picture for both ATL55 and ATL57.
Use this UEI page for better images and detail.
https://www.ueitest.com/search/node/leads (https://www.ueitest.com/search/node/leads)
The leads shown in the image posted above are definitely the ATL57 silicone series which are identifiable by the ridiculously long strain relief, the ATL55 series have a shorter strain relief.UEI uses the same picture for both on their website so you cannot belief what you see. When you open the data sheet you get a pdf where they use the exact same picture for both ATL55 and ATL57.
Use this UEI page for better images and detail.
https://www.ueitest.com/search/node/leads (https://www.ueitest.com/search/node/leads)
When you click on the link "HI-RES PICTURE" for the ATL55 you get a picture of completely other leads (???) and when you click on the "HI-RES PICTURE" link for the ATL57 you get a low res picture of the leads from the PDF.
Can anyone point me in the direction of a supplier for replacement fuses at reasonable price and preferably in Australia, failing that a UK supplier? I am after the 400mA but I may as well pick up both while I'm at it :-+Daves shop but it show he's out of stock.
I've received my meter together with the probes from UEI. I can take of a kind of plastic / rubber cap to get to the thread on the tips. I assume that the idea behind these threads is to be able to screw a banana plug tip to it to be able to connect it to some clamps for example (to to to ;-) ).
When I'm checking out the Brymen test leads online, it looks to me like they always come with those banana plug tips.
https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads (https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads)
I've assumed that the UEI leads would come with something like that too.
Are they missing in my package or does nobody have received them?
Max(https://uploads.tapatalk-cdn.com/20180815/e96d8a29aea5226dbaf636acc1673ab6.jpg)
Again, I am not suggesting this is a problem. Obviously, if you are expecting data to be collected with tighter sampling, it could be a problem.If you are talking about my posts (I haven't seen any other FFT on the data) I was trying to characterize the filtering and define where the noise was coming. In your test, in the samples between one resistor and the other doesn't make much sense to talk about noise, that's the response of the filter which will show intermediate data in the step, so that's what's closing your eyes (in the diagram, not that you are becoming blind).
I was original going to modulate the frequency and amplitude but the results from my initial test was so poor, you could not make sense of the data. So I simplified it to two states at a fixed frequency.
Alright, thank you very much!I've received my meter together with the probes from UEI. I can take of a kind of plastic / rubber cap to get to the thread on the tips. I assume that the idea behind these threads is to be able to screw a banana plug tip to it to be able to connect it to some clamps for example (to to to ;-) ).
When I'm checking out the Brymen test leads online, it looks to me like they always come with those banana plug tips.
https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads (https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads)
I've assumed that the UEI leads would come with something like that too.
Are they missing in my package or does nobody have received them?
Max(https://uploads.tapatalk-cdn.com/20180815/e96d8a29aea5226dbaf636acc1673ab6.jpg)
Edited: misread your comment.
The UEI leads do not come with the banana plug tips, however the bryman leads do.
In your test, in the samples between one resistor and the other doesn't make much sense to talk about noise, that's the response of the filter which will show intermediate data in the step, so that's what's closing your eyes (in the diagram, not that you are becoming blind).
When evaluating the Fourier transform the samples must be evenly spaced. This noise I am interested in is the jitter. The purpose of the two resistors is only to provide a known step change at discrete intervals. It could have been voltage or any other mode. That assumes that they all have the same jitter.
When Dave had first sent the meter, the fastest it could sample the data was at a one second interval. I had mentioned that there seemed to be a problem when writing to the SD card that it would hang (crash eventually). I suspect the some of this large error in sampling (time) is due to writing to the SD card. The BT may have less jitter. The prototype does not currently have the ability to use this feature.
Again, I am not normally concerned with noise in the time domain when using a handheld meter. It does make me wonder why they added the ability to log faster than a second with such high jitter.
****************
I should have made one other small point clear. The reason I am using the two small resistors close to the same value is that I did not want to add the effects of the auto range into the mix for this test.
I'm trying to connect the meter with my desktop using a BT dongle but I can't pair them. I'm using an old dongle. can you suggest me one working dongle?
no problem with my smartphone.
Let's start by just looking at some raw data. Again, the actual period of the toggle is fixed. Because the jitter in the meters sampling, it is not a nice periodic waveform. Should be easy enough to replicate.I see, there are flats from 10 to almost 20 samples. Are you suggesting the ADC reading is in such different intervales? I don't think the ADC would change so much, the readings from the µC is more likely the problem. Also, from the smaller look at your older pict of the raw data, V1.26 seems much more stable, isn't? The conversion results are jittery, no doubt, I wouldn't lock my clock onto the readings of that taking the reference somewhere else. My question now would be if the readings are shifting badly or the long term average out to a fixed-ish sampling rate.
What quantity is the vertical axis?
Alexander.
Are my previous posts not clear enough?
I have not ran a test like this with any of the other handheld meters I have. None of them can capture data this fast. It would be a nice feature if the meter could actually keep up storing the data or getting it across the wireless link. It is a bit odd that the resistance seems to have higher jitter than the voltage mode.
550.0406, 0.485
550.525, 0.485
551.0563, 0.485
551.5406, 0.484
552.025, 0.484
552.5563, 0.484
553.0406, 0.484
553.525, 0.484
554.5422, 0.484
555.0266, 0.484
555.5578, 0.483
556.0422, 0.489
556.5266, 0.489
557.0578, 0.489
557.5422, 0.489
558.0266, 0.489
558.5578, 0.488
559.0422, 0.488
559.5176, 0.487
560.0645, 0.487
560.5488, 0.486
561.0266, 0.487
561.5578, 0.487
562.0422, 0.486
562.5891, 0.486
563.0579, 0.486
563.5385, 0.486
564.0295, 0.486
564.5608, 0.486
565.0475, 0.485
565.5787, 0.485
566.104, 0.485
566.5461, 0.485
567.0305, 0.486
567.5618, 0.486
568.0421, 0.486
568.5889, 0.486
569.5421, 0.485
570.0264, 0.485
570.5665, 0.485
571.0352, 0.485
571.5821, 0.486
572.0665, 0.486
572.5352, 0.485
573.0821, 0.485
573.5665, 0.485
574.0352, 0.485
574.5352, 0.485
575.5352, 0.485
576.0821, 0.485
576.5665, 0.485
577.0352, 0.485
577.5821, 0.484
578.0665, 0.484
578.5352, 0.484
579.0821, 0.484
579.5665, 0.484
580.0352, 0.484
The noise of the 121GW prototype dominates the signal. The higher amplitude spikes appear very periodic.
You show about 8uV of drift over that 1000 seconds. It looks like my HP is about 4uV. It's strange how different the two meters behave.
The noise of the 121GW prototype dominates the signal. The higher amplitude spikes appear very periodic.
That noise is extreme. It's like you have a totally different meter. Maybe I should try logging to the SD card instead of BT and see what difference it makes with my one.QuoteYou show about 8uV of drift over that 1000 seconds. It looks like my HP is about 4uV. It's strange how different the two meters behave.
If the HP is the red line, it seems to drift down by less than half a division in 4000 sec, and 1 division is 5 µV, so that is about 2 µV in 4000 sec, or 0.5 µV in 1000 sec. Or am I reading it wrong?
The noise of the 121GW prototype dominates the signal. The higher amplitude spikes appear very periodic.
That noise is extreme. It's like you have a totally different meter. Maybe I should try logging to the SD card instead of BT and see what difference it makes with my one.QuoteYou show about 8uV of drift over that 1000 seconds. It looks like my HP is about 4uV. It's strange how different the two meters behave.
If the HP is the red line, it seems to drift down by less than half a division in 4000 sec, and one division is 5 µV, so that is about 2 µV in 4000 sec, or 0.5 µV in 1000 sec. Or am I reading it wrong?
Sorry, I'm a bit slow, if this was already mentioned: I just realized that "121GW" sounds pretty much like 1.21 gigawatts :)
I have not ran a test like this with any of the other handheld meters I have. None of them can capture data this fast.
Dr Frank was suggesting a higher test current for the low ranges.
Even if spec is claiming 0.5 % or so at marginal values for ranges this might be quite high like 10% for lowest range and test current like 10nA, or 1nA , or 1uA at 1000V etc.
I wrote a bit about it here: https://lygte-info.dk/info/DMMTolerances%20UK.html
I wonder how is doing 121GW comparing to others by tests.
I wonder how is doing 121GW comparing to others by tests.
When I tested it, it was inside the specified tolerances (with one exception).
https://lygte-info.dk/review/DMMEEVBlog%20121GW%20UK.html
I can not find test with nA test current. Did I missed this?
.....range and test current like 10nA, or 1nA , or 1uA at 1000V etc.
Are you trying to apply 1000V with a supply that is limited to a uA and measure the voltage? If you are trying to measure current, where does the 1KV fit in? I am not sure what you are asking.
Not uA and not like this, as simple as that:
- 100nA at any voltage (better 10 or 1nA, no idea how 121GW sensitive is)
- 100nA (better 10 or 1nA, no idea how 121GW sensitive is) at 1kV (1kV relative to ground , not accross multiemer)
That would be outside the specifications for the meter, it is only rated for 600V to earth.
That would be outside the specifications for the meter, it is only rated for 600V to earth.
I would not care for specifiation for such tests, but other hand I cannot ask anyone for potentialy destructive tests.
I would also not buy 121GW at this moment for own tests, it looks not mature to me.
Hi,I think all of us who bought this meter were shocked at the springs fitted in the battery holder. A well made battery holder fitted with springs which are simply too long.
that is true, the battery holders are terrible. That was also my first impression.
The worst springs of all my battery powerd instruments. I have aligned the springs with a small tweezer, so now it lookes a bit better.
Beside of this a great meter with some room of improvement in the firmware.
@CDaniel - Why not use the provided range switch?
This multimeter has in theory an 50000 counts display , than range switching upward at 55000 counts but downward at 40000 counts is supposed to be a feature ?I would consider this quite normal, though the hysteresis is a bit on the wide side.
I find this rather annoying ... lets say I want to adjust a 5.0000V voltage refference , if I go up beyond 5.5000V I lose the last digit of resolution because is switching the 50V range , but then if I adjust downward I can't get it back since it remains in 50V range until it reaches 4V
Counts | Up at | % | Down at | % | |
6000 | 6.600 | +10 | 5.40 | -10 | |
20000 | 19.999 | +0 | 16.80 | -16 | (Of course, it can't display > 19999) |
Sure I can , but I don't think is normal to be 2 thresholds , that is my point .It's definitely normal! Without hysteresis you would have continuous range change at the threshold, a much worse experience.
Sure I could , but I don't think is normal to be 2 thresholds , that is my point .
And that was just an example .
Sure I could , but I don't think is normal to be 2 thresholds , that is my point.
And that was just an example.
I couldn't take it any longer :-/O
...
Great idea!
The meter could be made with a small removable cover for this very purpose and retain rating?
...
Ok, I have to ask. Did you make this modification because you log a lot to the SC card or was it because of the number of firmware updates you have done?
...
I couldn't take it any longer :-/OBrilliant!
Has anyone stopped for a second and asked why such a cutout might NOT be a good move?Its his meter and he can hack it to how it works best for him!
The issue isn't new. It has been discussed during earlier development.
Has anyone stopped for a second and asked why such a cutout might NOT be a good move?Its his meter and he can hack it to how it works best for him!
The issue isn't new. It has been discussed during earlier development.
Just as you can do whatever you want to your meter, hack away or not, its your choice!
Has anyone stopped for a second and asked why such a cutout might NOT be a good move?Correct,
The issue isn't new. It has been discussed during earlier development.
I never said he couldn't do whatever he wanted to do to his own meter. I just raised the point as to why it might not be a good move.
If someone KNOWS what the implications are and chooses to make such a modification, then fine. But DON'T start espousing this as a GREAT IDEA - whether or not you appreciate the risk.
SO if you want to blindly advocate such a modification - then you need to pull your head in. IMHO.
Your "You're" entitled to your opinion, but I would expect you to keep touch with reality and actually read what I have posted before making such misleading and mischievous comments!
If you struggle to comprehend the english language then maybe you should take a refresher course or you may have just had a bad day and needed to blow of some steam?
Sorry, couldn't help myself. :-DD :-DD Believe me, this is a case of the pot calling the kettle black.
I never said he couldn't do whatever he wanted to do to his own meter. I just raised the point as to why it might not be a good move.
If someone KNOWS what the implications are and chooses to make such a modification, then fine. But DON'T start espousing this as a GREAT IDEA - whether or not you appreciate the risk.
SO if you want to blindly advocate such a modification - then you need to pull your head in. IMHO.
Brumby, Brumby, Brumby, what are we going to do about your lack of reading comprehension and BS statement?
Ok, firstly I didn't advocate for everyone to make the modification, thats your BS spin on it.
Great idea!This sounded like encouragement to me. It certainly was an endorsement.
I liked the idea of having the SD card accessible and even asked the question, if it might have a cover provided to keep the rating!A subtle difference from your original statement. It still didn't acknowledge the potential issues of trying to do that.
Have you actually purchased this meter yet Brumby?I knew you would throw this up. You might be surprised to learn that I don't need to have the meter in my possession to be able to make valid comment about some aspects of it - especially when the subject had already been discussed some time ago. You might also note that, at no time, have I entered into any discussion on the 121GW where I have offered comment or information that was based on possession.
Your entitled to your opinion, but I would expect you to keep touch with reality and actually read what I have posted before making such misleading and mischievous comments!Here's a pot and kettle moment if there ever was one. :palm:
If you struggle to comprehend the english language then maybe you should take a refresher course or you may have just had a bad day and needed to blow of some steam?
Have you actually purchased this meter yet Brumby?
I beg to differ, if you actually owned this meter and used the SD card for data logging as well as for firmware updates you would understand that easy access to this card would be a huge benefit!I'm sorry for saying this - but you are an ass. One does not have to own or use this meter to appreciate the hassle involved. It's been mentioned many times. To say I would not understand the benefit of the hack is dumb and just seems to be a way for you to try and justify yourself.
Apologies for not walking away as I promised - but this just has to be addressed...
Is there an estimate when these will be available to those of us who didn't see the Kickstarter? Dave's product page lists it as out of stock. If it matters I'm in the US.
I have noted that the 121GW goes "in stock" in lots of 32 units. These units are usually sold within a week. Just keep checking every couple of days and keep that credit card handy. Check on the site too because (if memory serves) they ship on Tuesday and Thursday (australia time). I got my meter in the Boston, MA, USA area about 5 days after shipping, which is pretty good. This was a few weeks ago and so this is a fairly up-to-date description of the process.
That would be useful for people with hearing loss or just someone working in a very noisy environment.
Well, I don't have a 121GW yet, so I can't comment, but the BM235 flashes the backlight in continuity mode - and it does so whether the backlight is off or had been turned on. (Yes, I have a BM235).
If the 121GW doesn't have this feature, I would like to see it implemented. The option to switch off the beeper is one I would be guarded about. That is a setting I would want to have automatically reset at switching off so the next time I turn the meter on, I don't interpret silence as a lack of continuity.
Does anybody know if there will be an option to NOT store the last settings of the functions?That is sorely needed IMO.
Many little features can be added , but there are some important ones not very good implemented .
For exemple capacitance measurement has low resolution , only 3 digits 1000 counts , so for 220nF you can't see anything extra . And very , very slow autoranging in comparison with other multimeters. HY3131 is capable for more performance
The backcover om my 121gw is a very tight fit and would never fall off by it self - so I just don’t tighten the two screws at all if I’m doing any logging.
Hi,
This is indeed slow, but I assume the logging data transfer is synchronised with the ADC sampling and would be faster with a datatransfer from the SD card?
Well, I'm not so sure. They write to the SD card much faster than they send the data over BLE. They have even slowed down the BLE transfers compared with the early firmware versions. I assume they were trying to improve reliability by going from ASCII to binary, reducing the payload and then slowing it down but I'm not sure. The meter can certainly update faster than 2Hz so I don't believe it would speed up if they were doing a data transfer.
Again, I am not suggesting it could not be done only that from what I see, it appears throttled like Barbie's Mustang and not Grind Hard Plumbing's version.
https://www.youtube.com/channel/UCivi_f1nniBzEOfKhRoN12Q (https://www.youtube.com/channel/UCivi_f1nniBzEOfKhRoN12Q)
There is a fair bit of overhead sending that one byte packet. :-DD
There is a fair bit of overhead sending that one byte packet. :-DD
There were other motivating factors also which included differences in implementation for BLE on different platforms. Some platforms have a longer buffer than others and it needed to come in one packet.
The number of platforms this device supports was also a factor in the reduction of the packet size.
From the link that you provided, your issue is with DHL, not with Suse or Jonestronics. I am dumbfounded that you didn't contact the carrier back in September.
I'm not the one arranging shipment so I don't think it's unreasonable to expect the folks over at Jonestronic to follow-up on their end. In my experience, when you purchase something online and it doesn't come through, usually the vendor is the one that has to follow up with the shipping company. Is this not your experience as well?
I'm not the one arranging shipment so I don't think it's unreasonable to expect the folks over at Jonestronic to follow-up on their end. In my experience, when you purchase something online and it doesn't come through, usually the vendor is the one that has to follow up with the shipping company. Is this not your experience as well?
Definitely down to the seller to sort out.
It is the person that made the contract with the shipper that has to deal with it.
I just ordered 1 today! Yikes!! :o
I have a few available on ebay for those in Oz:
https://www.ebay.com.au/itm/223244201244 (https://www.ebay.com.au/itm/223244201244)
My web shopping cat is currently rooted, being in investigated.
Big shipment of meters finally due next week.
ebay is a pain in the ass which is why I packed it in. I have actually just bought the shiiping plugin for woocommerce so that I can do flexible shipping in my shop based on weight so that i can sell some small parts without having to charge one shiping rate no matter what.
Last time I had a problem buying on ebay I found it impossible to contact ebay when the seller would not play ball. so I avoid ebay for buying as well now.
Why don't you get one from Welectron?
https://www.welectron.com/ (https://www.welectron.com/)
That's where I got mine. Sipped in just under 5 days from Germany to the UK.
Soon I will hopefully have quite a few directly from Dave to resell. I also have one of the first batches for me personally already. I was simply musing on the feseabilities of selling on ebay. I considered selling Daves products on ebay but decided that given the following Dave has and i am his UK distributor why bother. I would have to add at least 10% to the price and in fact due to the hassle factor of doing business on ebay I would put way more than 10% on. As i have just discovered ebay is shit for buyers as well as sellers so avoid it entirely unless i am prepared to loose my money as a buyer like i have done once already.
Why don't you get one from Welectron?
https://www.welectron.com/ (https://www.welectron.com/)
That's where I got mine. Sipped in just under 5 days from Germany to the UK.
Why don't you get one from Welectron?
https://www.welectron.com/ (https://www.welectron.com/)
That's where I got mine. Sipped in just under 5 days from Germany to the UK.
I'm in the US, finding a US retailer would be best, if not probably ebay is going to be cheaper. In the worst case I prefer to buy directly from the eevblog store.
Just as a heads up it looks like the 121 gw is back in stock in the store.
https://www.eevblog.com/product/121gw/ (https://www.eevblog.com/product/121gw/)
I believe Dave posted somewhere of getting a boat load of units so the 121 gw should be in stock for a while.
The correct fix would be to adjust the thickness of the switch rotor (the bit that holds the contacts :D), to add the required amount to take up the slack between the top case and the PCB mounted rotor,
The PCB is a fixed size (within usual tolerance limits.).
But still maybe the shim is still the best economical/engineering solution without costly injection mould redo's.This.
It has been found that the switch contact issues were ultimately caused by a slight PCB thickness difference between the pre-production and production boards.Does "the low side" mean that the board is too thin? Is the 0.95mm shim meant to be attached to the circuit board? Just confused a bit.
Pre-production boards were on the high side of the tolerance allowance, and production boards on the low side. Actually, the production board thickness was actually slightly outside of UEi's board spec.
A 0.95mm shim (as has been found by others) is the fix for existing units and current stock boards (i.e. all Kickstarter ones and for sometime afterwards). Future volume production boards shouldn't need a shim however.
Shims are on the way to me now for cycle testing.
Yes, on the thin side.
The shim goes between the plastic range switch and the case, as per how others have done their own DIY solution.
For those that want to do it themselves, the shim thickness is 0.95mm.
The question is are the new batch of meters any better than the kickstarter meter?
Is the new meter still using the spacer?
Has the new meter any new components and specification?
Does the new meter still have the existing firmware bugs?
Dave is there any difference with the new over the old?
The latest meters shipping have two hardware changes. A copper shield, and a two transistor daughter board to replace the TVS.
The latest meters shipping have two hardware changes. A copper shield, and a two transistor daughter board to replace the TVS.Can we see pictures, especially of the shield?
These seem like things that might be relevant retro-fits.
Is that a TI CD4053B with an absolute maximum Vsupply of 20V??
Sure, there's some new shield and clamping... but what's this I see!!!????
Is that a TI CD4053B with an absolute maximum Vsupply of 20V?? The same part I have said several times that I went to in an attempt to get the meter to survive some basic transients???!!!! Looks like someone is trying to spoil my fun. If they get the clamping right, this meter should do just fine.
Looking forward to seeing the meter finished up. :-+
Sure, there's some new shield and clamping... but what's this I see!!!????Joe, does changing to this spec chip alter calibration?
Is that a TI CD4053B with an absolute maximum Vsupply of 20V?? The same part I have said several times that I went to in an attempt to get the meter to survive some basic transients???!!!! Looks like someone is trying to spoil my fun. If they get the clamping right, this meter should do just fine.
Looking forward to seeing the meter finished up. :-+
What "basic transients" or voltage levels did you apply during your testing which destroyed the 4053?
The latest meters shipping have two hardware changes. A copper shield, and a two transistor daughter board to replace the TVS.Can we see pictures, especially of the shield?
These seem like things that might be relevant retro-fits.
Attached.
The shield is a multi-layer plastic sandwich construction. You could DIY, but watch for shorts and clearances etc. Connected to the negative battery clip on the other side.
Again, this will only be for existing stock of blank PCBs.
How long before the next gen 121GW becomes available with the new PCB and updates?
I'm quite happy to hardware mod my current 121GW and would love to see a video on EEVBlog on the modding and re-calibrating this meter.
The shield - a fix for the jumping values when interacting with the membrane buttons?
Is there a suggested process to make (or purchase from EEVBlog) a shield in earlier models?
Is there a suggested process to make (or purchase from EEVBlog) a shield in earlier models?
I could ask Kane to send me a whole bunch I guess for those that want them.
Is there a suggested process to make (or purchase from EEVBlog) a shield in earlier models?
I could ask Kane to send me a whole bunch I guess for those that want them.
Dave, start a list of those wanting the button shield and add me to it!
I would appreciate the added stability it would bring to the meter.
Is there a suggested process to make (or purchase from EEVBlog) a shield in earlier models?
I could ask Kane to send me a whole bunch I guess for those that want them.
As Dave stated above this would mean a re-calibration which uses equipment that most users would not have ready access to, so is best to leave as is. Of course having the PCB available to those that do have the required gear would be nice too ;).Is there a suggested process to make (or purchase from EEVBlog) a shield in earlier models?
I could ask Kane to send me a whole bunch I guess for those that want them.
And a two transistor daughter board to replace the TVS.
Its a pity that UEI and EEVBlog didn't bite the bullet and scrap the 700 out of spec PCBs that require shims for the switch to work properly. The hardware upgrades could have been incorporated on the new PCB giving the meter the stability and speed it requires to lift itself from being just another kickstarter prototype.How long before the next gen 121GW becomes available with the new PCB and updates?
Well past this batch of 700, they have a lot of blank boards yet. Can't give a timeline.QuoteI'm quite happy to hardware mod my current 121GW and would love to see a video on EEVBlog on the modding and re-calibrating this meter.
Most people do not have the capability to calibrate the meter, it requires precise generated values from a proper meter calibrator.
The big issues are firmware related , the shim is working fine for the majority ( I don't want to say that they shouldn't do it right ). And that little shield for buttons + modified protection in resistance mode won't change much .
Funny. I don't see the firmware being big issues. Certainly there are more firmware problems reported than hardware and they may be more visible to the average joe but I see getting a stable hardware platform as being a larger problem.
Seeing them change from the single dimple contact to double and now back to single. Looking at photos of the wear, I'm not convinced the meter will hold up. Dave did run a life test on some version of it but it seems odd they are changing the design if all is well. The same is true for the transient protection. If Dave is going to make a statement that the meter passed cert and that's the end of the story, then there should be no reason to change the front end. It's good to hear they continue to develop the hardware. I'm looking forward to seeing what they come up with.
Its a pity that UEI and EEVBlog didn't bite the bullet and scrap the 700 out of spec PCBs that require shims for the switch to work properly. The hardware upgrades could have been incorporated on the new PCB giving the meter the stability and speed it requires to lift itself from being just another kickstarter prototype.How long before the next gen 121GW becomes available with the new PCB and updates?
Well past this batch of 700, they have a lot of blank boards yet. Can't give a timeline.QuoteI'm quite happy to hardware mod my current 121GW and would love to see a video on EEVBlog on the modding and re-calibrating this meter.
Most people do not have the capability to calibrate the meter, it requires precise generated values from a proper meter calibrator.
I needed another similar spec meter and would have waited for the upgraded 121GW to appear if it featured the necessary upgraded hardware. As you could not provide a time frame or even list the fixes that would appear in the next production model I have purchased another meter.
I purchased the similar priced Brymen BM867s, ($300) as I know what the performance and accuracy are and how reliable this meter has shown to be under many different tests. This is a professional and proven design that features fast update rates and stable display readings. IMO this older Brymen meter's performance is what the 121GW needs to match and better if it is to stand the test of time and continue to sell.
The big issues are firmware related , the shim is working fine for the majority ( I don't want to say that they shouldn't do it right ). And that little shield for buttons + modified protection in resistance mode won't change much .
Funny. I don't see the firmware being big issues. Certainly there are more firmware problems reported than hardware and they may be more visible to the average joe but I see getting a stable hardware platform as being a larger problem.
Seeing them change from the single dimple contact to double and now back to single. Looking at photos of the wear, I'm not convinced the meter will hold up. Dave did run a life test on some version of it but it seems odd they are changing the design if all is well. The same is true for the transient protection. If Dave is going to make a statement that the meter passed cert and that's the end of the story, then there should be no reason to change the front end. It's good to hear they continue to develop the hardware. I'm looking forward to seeing what they come up with.
The big issues are firmware related , the shim is working fine for the majority ( I don't want to say that they shouldn't do it right ). And that little shield for buttons + modified protection in resistance mode won't change much .
Funny. I don't see the firmware being big issues. Certainly there are more firmware problems reported than hardware and they may be more visible to the average joe but I see getting a stable hardware platform as being a larger problem.
Seeing them change from the single dimple contact to double and now back to single. Looking at photos of the wear, I'm not convinced the meter will hold up. Dave did run a life test on some version of it but it seems odd they are changing the design if all is well. The same is true for the transient protection. If Dave is going to make a statement that the meter passed cert and that's the end of the story, then there should be no reason to change the front end. It's good to hear they continue to develop the hardware. I'm looking forward to seeing what they come up with.
I still believe both need to be taken care off but the biggest concern I now start to have is transparency on why the changes are happening single to double and back etc. For me there was never a good response on why my meter had so much crud on the contacts after less then 100 power cycles. It took also quite some time to acknowledge the mechanical issue with the selector knob. All and all I am personally okay to support such an initiative, spend the money accept the risk of a possible lemon or brick but then I see room for improvement on the development process going forward. I do want to acknowledge here too that we can on this forum give plenty of updates, issue reporting or even rant on whatever we think should have been done and that in itself is worth something already.
If i'd have known there was a newer updated model due out I would have waited rather than buy one a week or two ago! :(
But there ya go… I suppose!
What you complain of is routine across most products. Really, go and check.
Right and there isn't a newer version or model.
The same model has received a small improvement. This happens all the time in all sorts of electronics. IT IS NOT A NEWER VERSION OR MODEL. Also, this incremental improvement does not change the published specs. From the description, it provides the meter with some stray RF noise immunity. This is a good thing but probably makes no difference for many users. Anyone who works in a development environment can tell you that a particular make/model is always getting tweaked in subsequent manufacturing runs.
Seeing them change from the single dimple contact to double and now back to single. Looking at photos of the wear, I'm not convinced the meter will hold up. Dave did run a life test on some version of it but it seems odd they are changing the design if all is well.
It took also quite some time to acknowledge the mechanical issue with the selector knob.
Right and there isn't a newer version or model.
The same model has received a small improvement. This happens all the time in all sorts of electronics. IT IS NOT A NEWER VERSION OR MODEL.
If you thought about what I wrote (you didn't), you would wait forever. Not just for test equipment but for cars, microwave ovens, tv sets etc. EVERYTHING gets tweaked from time to time. Unless you plan on using your 121GW around intense RF fields, this improvement means nothing.
The 121GW you bought meet specs. The later ones meet specs. You paid for something that meets specifications. The addition of the shield is probably to mitigate support questions more than anything. That's usually the case with this sort of thing.
Do you even know or did you even think about whether the shield would be better for your uses? Do you even know or think about what you would have to pay for something with the same feature set as what is specified, but also with more accuracy, ruggedness, shielding or whatever? Every product targets a price point and a perceived need. This one does. OTOH, if you need something else, you should have bought that one.
If you thought about what I wrote (you didn't), you would wait forever. Not just for test equipment but for cars, microwave ovens, tv sets etc. EVERYTHING gets tweaked from time to time. Unless you plan on using your 121GW around intense RF fields, this improvement means nothing.
The 121GW you bought meet specs. The later ones meet specs. You paid for something that meets specifications. The addition of the shield is probably to mitigate support questions more than anything. That's usually the case with this sort of thing.
Do you even know or did you even think about whether the shield would be better for your uses? Do you even know or think about what you would have to pay for something with the same feature set as what is specified, but also with more accuracy, ruggedness, shielding or whatever? Every product targets a price point and a perceived need. This one does. OTOH, if you need something else, you should have bought that one.
Right and there isn't a newer version or model.
The same model has received a small improvement. This happens all the time in all sorts of electronics. IT IS NOT A NEWER VERSION OR MODEL.
Correct. This is not a new version or model, and there is no new version or model underway. The shim will eventually be removed, and the current mods will be integrated into a new PCB, but there are no plans for other improvements or spec changes. We are more focused on getting the firmware and development system improved, and a new shared version control system is being setup with the intention that we (EEVblog) will now have visibility on firmware changes, and also the ability to eventually make changes and compile/test ourselves.
Right and there isn't a newer version or model.
The same model has received a small improvement. This happens all the time in all sorts of electronics. IT IS NOT A NEWER VERSION OR MODEL.
Correct. This is not a new version or model, and there is no new version or model underway. The shim will eventually be removed, and the current mods will be integrated into a new PCB, but there are no plans for other improvements or spec changes. We are more focused on getting the firmware and development system improved, and a new shared version control system is being setup with the intention that we (EEVblog) will now have visibility on firmware changes, and also the ability to eventually make changes and compile/test ourselves.
Dave, it may not be a complete new model, but it will be a substantial Revision of the current model. The reason I did not buy another 121GW was because UEI and EEVBlog have decided to use up the remaining 700 out of spec PCBs.
While this may make some sort of financial sense to you and UEI it made absolutely no sense to me as a customer as I dont want another prototype meter. I already have my kickstarter meter that I bought because of your involvement with it. I want my test meters to last and the switch and shim solution are at best a temporary fix. Problem is that you and UEI have decided to carry on with it and let your customers carry the risk of early failure.
I wonder how much better the sales of the 121GW would be if you made it clear to customers that the new revision meters had a new PCB with hardware updates and a reliable switch with a stated switch cycle life. I dont think I am alone in deciding that an alternate meter would be a better choice until you and UEI bring this meter up to spec!
Make the responsible decision that is right for the customers and suffer a tiny financial loss on the out of spec PCBs and you will find this meter becoming a best seller. If you do it on the cheap and let your customers carry the risk IMO then you carry the risk of not having any customers.
I have a Brymen BM867s on its way and I would have preferred a properly made 121GW meter instead.
I got side tracked yesterday so didn't get to test the "hysteresis" but I will do it today for sure and post the results.I don't think you'll get different results from what's already known (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1829909/#msg1829909).
I got side tracked yesterday so didn't get to test the "hysteresis" but I will do it today for sure and post the results.I don't think you'll get different results from what's already known (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1829909/#msg1829909).
In the linked post, for reference, the behaviour of Fluke 87V.
Just to make sure, I quickly retested with FW 1.57, for DC V (5V range) and mA (5mA range): the thresholds are still 40000-55000 counts (-20% + 10% wrt nominal 50000).
While this may make some sort of financial sense to you and UEI it made absolutely no sense to me as a customer as I dont want another prototype meter. I already have my kickstarter meter that I bought because of your involvement with it. I want my test meters to last and the switch and shim solution are at best a temporary fix. Problem is that you and UEI have decided to carry on with it and let your customers carry the risk of early failure.
While this may make some sort of financial sense to you and UEI it made absolutely no sense to me as a customer as I dont want another prototype meter. I already have my kickstarter meter that I bought because of your involvement with it. I want my test meters to last and the switch and shim solution are at best a temporary fix. Problem is that you and UEI have decided to carry on with it and let your customers carry the risk of early failure.
We are confident the shim solution will not lead to "early failure".
I hate to point this out (well, not really) but you seem to be making the assumption that the shim solution is less of an engineering decision than the original design.
Let me throw out this purely hypothetical (but not impossible) idea......
It is not inconceivable that the implementation of the shim might actually be a superior solution - something that we may only see after some years of use.
If you want to ask me how, I don't know and I could only speculate. If I were able to identify a specific engineering case that supports such a scenario, then I think the designers that have been working with this stuff for years might also have been able to have a handle on such an idea. As it is, I believe that expertise allowed them to come up with the shim as a viable and reliable solution.
Please ... get over this.
While this may make some sort of financial sense to you and UEI it made absolutely no sense to me as a customer as I dont want another prototype meter. I already have my kickstarter meter that I bought because of your involvement with it. I want my test meters to last and the switch and shim solution are at best a temporary fix. Problem is that you and UEI have decided to carry on with it and let your customers carry the risk of early failure.
We are confident the shim solution will not lead to "early failure".
Thats all well and good but I would feel a lot more reassured if that confidence you have in the "shim solution" actually had a long warranty period supporting it!
Looking at the EEVBlog website I could not find and warranty/refund/return policy listed. Can you please provide a link to the warranty information for the meter or for anything that you sell from your eStore?
Warranty terms are specified in the manual. First pages...
I paid $341 for the meter which includes GST and delivery. Assuming EEVBlog have sold approx 3500 of them 3500 x $341 = $1,193,500! Congrats to EEVBlog!
I paid $341 for the meter which includes GST and delivery. Assuming EEVBlog have sold approx 3500 of them 3500 x $341 = $1,193,500! Congrats to EEVBlog!
Now you just have to subtract the costs of design, production, shipping and support.
I paid $341 for the meter which includes GST and delivery. Assuming EEVBlog have sold approx 3500 of them 3500 x $341 = $1,193,500! Congrats to EEVBlog!
Now you just have to subtract the costs of design, production, shipping and support.
Never underestimate that one! :-DD A friend of mine was having some problems with a little electronic device he had bought. He brought it over for me to have a look at. It was an impressive bit of hardware and seemed to work like a champ. I called the company that produced it and ended up talking with the designer who told me they no longer offer it. I said why? This is a great product. It's small and light weight, very well made, lots of features and seems to be bullet proof. Cost wasn't bad.
I proceed to hear the story of how the people that bought them had problems with troubleshooting simple circuits and basic wiring. Many had problems reading the manual and the device was always to blame. Many were returned with no problems found and in the end they spent more money in time trying to support it than they were making from sales, so they pulled the plug on it.
I paid $341 for the meter which includes GST and delivery. Assuming EEVBlog have sold approx 3500 of them 3500 x $341 = $1,193,500! Congrats to EEVBlog!
Now you just have to subtract the costs of design, production, shipping and support.
Never underestimate that one! :-DD A friend of mine was having some problems with a little electronic device he had bought. He brought it over for me to have a look at. It was an impressive bit of hardware and seemed to work like a champ. I called the company that produced it and ended up talking with the designer who told me they no longer offer it. I said why? This is a great product. It's small and light weight, very well made, lots of features and seems to be bullet proof. Cost wasn't bad.
I proceed to hear the story of how the people that bought them had problems with troubleshooting simple circuits and basic wiring. Many had problems reading the manual and the device was always to blame. Many were returned with no problems found and in the end they spent more money in time trying to support it than they were making from sales, so they pulled the plug on it.
So you had a friend who bought this great little product that that was very well made with loads of features and was bullet proof and worked like a champ but the people who bought it couldn't wire simple circuits or do basic wiring and many couldn't read the manual and blamed the device but the device had no problems and was great so the company pulled the plug?
Really? :-DD
So you had a friend who bought this great little product that that was very well made with loads of features and was bullet proof and worked like a champ but the people who bought it couldn't wire simple circuits or do basic wiring and many couldn't read the manual and blamed the device but the device had no problems and was great so the company pulled the plug?
Really? :-DD
If marketed to the wrong demographic, I could see that happening - though that does reflect badly on the marketing strategy. Perhaps they aimed too wide and the less technically inclined were the greatest uptake.
It is a strange world - and no matter how good a product may be, if the cost of the business is greater than the revenue, then the only sensible option is to close up shop.
The troll speaks. Yes, and it shows you can actually read. I'm impressed.
Notice the wear around the lip of the hole.
The shim thichness is not relevant because normally there is a empty space between the switch and the case ... so actually could be a very little push from the shim . My multimeter with the board out of the case is working well if I turn the switch , is not that loose not to make contact without the shim .
So the PCB needs to be just a little thicker . Thats the good solution , because with the shim , all the case tolerances , how the pcb sits on the case screw mounts play a role ... and you could have in the end too little pressure or to much . If something is not straight the wear will be more in one side .
Looked fine to me. From a strictly engineering point of view I would have liked to see an additional washer, longer barrel and maybe a circlip used instead of the clip but so far the clips are doing their job.
Just a potted theory yours spent more time than most without a shim? (not sure if you got a second meter from Dave?) So is yours indicative of what those of us with shims installed from scratch or fairly early into the life of the meter can expect or is it just what is possible without the shim for period X and then fitting one later?
EDIT: Just trawled my photos from Shim arrival time and none of the meter or PCB
Just by way of contrast to Joe's pictures above I knocked mine down for the first time since I installed the shim today firstly to upgrade the inferior 1.15 firmware that I have been using since it was first released to 1.57, yes I am that lazy when something works.Have you had a close up look at the switch spring contact dimples to see if there is any notable wear either even or uneven ...or not !.
I got a first production kickstarter meter stickered #137 and the follow up shim kit when first released was installed straight away.
These photos are taken with no clean up of any sort to the board or contacts and no colour or contrast corrections. Just here for comparison not to start a pissing contest. A bit of wear on one side but most of that was there if I recall pre shim.
Hey all, I see the 121GW can measure temperatures >1000C in the manual! Just wondering if the thermocouple is safe to put into a conventional oven to test the temperature (multimeter of course outside).
Hey all, I see the 121GW can measure temperatures >1000C in the manual! Just wondering if the thermocouple is safe to put into a conventional oven to test the temperature (multimeter of course outside).
Cheers!
How did it look on the back side where the locking tabs ride?
One very happy customer.After watching review of other multimeters on YT of UEI, I was quite sure how it will go . Just look at old review of Dave for UEI multimeter - I think it was 100$ multimers review - and reflect the same criteria to 121GW.
Here is another use for the 121GW. In keeping with the traditions of obscure complaints, I have a quibble with the migraine inducing high frequency of the "continuity test". Also, it seems to not "unlatch" quite to my satisfaction as I send dots and dashes at 60wpm. Finally, it was rather thoughtless that the meter can't receive Morse code to change the configuration. Wouldn't that be so handy if one is swinging from the rungs of a transmission tower, making measurements, I should not deign to actually touch the meter? If I paid all this money for Code Practice Oscillator, I think it should be better than $10.00 one that is sold for that purpose.
KC1KNS
Hello,
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
Thank you !
Hello,
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
Thank you !
So what are your needs?
Unfortunately i could not reach a conclusion on my own
Would you recommend this meter to be purchased in 2019 ?Yes I would.
Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?Not that I know of or that would keep me from recommending it.
Thank you !You are welcome.
Hello,
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
Thank you !
..It was worth it in 2018 and haven't seen any regressions, so yes in 2019 or beyond, it will only get better.
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
..
I am interested in a device to use in low-voltage electronics work, although i don't see the relevance of this information...
..It was worth it in 2018 and haven't seen any regressions, so yes in 2019 or beyond, it will only get better.
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
..
The only real issue IMO is the slow auto-range and showing incorrect results for a second before the real results. This is currently resolved by manually selecting the range after you set R, V ect. It won't remember the range after a function switch unfortunately. I think this will get resolved in one way or the other at some point.
Its my main meter of two. Though as I look at my stuff while I write this, I can't find the old meter!
So I looked into the resistance range, its improved somewhat. Instead of scanning down from 50M it scans up from 50R, this way the burden of the slower higher ranges isn't placed on the lower ranges, if you want to try this version of firmware its here, its a beta, I haven't tested everything I wanted to yet:
https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=21118 (https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=21118)
So I looked into the resistance range, its improved somewhat. Instead of scanning down from 50M it scans up from 50R, this way the burden of the slower higher ranges isn't placed on the lower ranges, if you want to try this version of firmware its here, its a beta, I haven't tested everything I wanted to yet:
https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=21118 (https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=21118)
Hello,
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
Thank you !
@Seppy
I didn't try the download yet as the file size is only 60k as opposed to the usual ~130. Is this ok or is it a zip or something the name was 'EEVBlog1_58.7z'
I see file is compressed with yet another file compression method. On Mac you will need to search app store for .7z. Many free apps are available.
We understand your point of view ... your hobby testing how robust a meter is . As a user you dont care that much if the switch won't last only 20K cycles in the future ... but the firmware is buggy now :-\ and you can't use it as you would like .I would be pissed if I paid 300+ for a meter and the switch went bad in the first year or two. The UNI-T was only $30 and really what I expect from a cheap meter with nominal use. Same for BK and Mastech. I consider them disposable. But at $300 it better be built to stand the test of time.
The 1_58 beta is interesting so far. Switching from say V to ohms with a 4.7k resistor attached is almost immediate :clap:, thought I had the wrong meter :-DD. This apparently is my new way of starting a resistance reading.
However, once in resistance mode and you disconnect the resistor it will auto range to the 50meg range. When you re-attach a resistor it is faster than 1_57 for sure but somewhat randomly still shows a quick flash in the mega ohm range before auto ranging from the bottom. Definitely an improvement.
We understand your point of view ... your hobby testing how robust a meter is . As a user you dont care that much if the switch won't last only 20K cycles in the future ... but the firmware is buggy now :-\ and you can't use it as you would like .I would be pissed if I paid 300+ for a meter and the switch went bad in the first year or two. The UNI-T was only $30 and really what I expect from a cheap meter with nominal use. Same for BK and Mastech. I consider them disposable. But at $300 it better be built to stand the test of time.
Same holds true for basic transients. Last thing I want is a meter like my first brand new Fluke. Look at it wrong and a $70+ dollar repair bill, that was in the 80s. Firmware can be fixed but if the hardware is wrong, there is little you are going to do to correct it.
My normal use of a handheld meter is pretty basic. That's why I buy cheap, disposable meters for the garage. The 121GW would be out of place in that environment.
We understand your point of view ... your hobby testing how robust a meter is . As a user you dont care that much if the switch won't last only 20K cycles in the future ... but the firmware is buggy now :-\ and you can't use it as you would like .I would be pissed if I paid 300+ for a meter and the switch went bad in the first year or two. The UNI-T was only $30 and really what I expect from a cheap meter with nominal use. Same for BK and Mastech. I consider them disposable. But at $300 it better be built to stand the test of time.
Same holds true for basic transients. Last thing I want is a meter like my first brand new Fluke. Look at it wrong and a $70+ dollar repair bill, that was in the 80s. Firmware can be fixed but if the hardware is wrong, there is little you are going to do to correct it.
My normal use of a handheld meter is pretty basic. That's why I buy cheap, disposable meters for the garage. The 121GW would be out of place in that environment.
For potential buyers is important to know the switch longevity , but users can't do anything as you said ( besides beeing pissed >:()
So we concentrate on what can be changed , the firmware .
And without a mature firmware many switches will last for ever , who would use daily such a multimeter ?
Hello,
I would like to ask owners of the 121GW: Would you recommend this meter to be purchased in 2019 ? Are there still any software issues that still need to be resolved ? Are there any missing, unimplemented, features ?
Thank you !
Many (most?) meters at this price don't support firmware updates at all.
I would like to thank everyone for the valuable feedback. I was under the impression that resistance measurement was recently improved to around 4.2-4.5 seconds.
The range switch reliability is something which i haven't thought about and is a valid point: No matter how feature-full and accurate, how are you going to use your device if you can't turn it on ?
The above is an extreme example of course, but the idea of joeqsmith (mechanical stress) is well worth taking into consideration.
@exe Personally, I do not believe in objective, non-polarized opinions of people, which is why i'm interested in everyone's opinion. Polarization is the reason that i've chosen this thread to post in.
Again, Thank you !
Many (most?) meters at this price don't support firmware updates at all.
Because they don't need it? >:D
"Just to be clear, I bricked it with own firmware, not with the stock one."
You can't play with it so much , it is complicated to reverse engineear the code and maybe doesn't worth the pain ... so it is not hackable , just in theory .
I'm aware only for that "Hello World" on display , that is not difficult to create if you find in code the text "U-1.57" - the current software version displayed at start-up . You can replace it with everything ... your name maybe . But to reverse engineer all , without the source code and to understand it , is much harder than to write your own code from scratch . A decompiler will give you something , but is not the original code , much must be interpreted and are many ways . That's why it is useless .
We understand your point of view ... your hobby testing how robust a meter is . As a user you dont care that much if the switch won't last only 20K cycles in the future ... but the firmware is buggy now :-\ and you can't use it as you would like .I would be pissed if I paid 300+ for a meter and the switch went bad in the first year or two. The UNI-T was only $30 and really what I expect from a cheap meter with nominal use. Same for BK and Mastech. I consider them disposable. But at $300 it better be built to stand the test of time.
Same holds true for basic transients. Last thing I want is a meter like my first brand new Fluke. Look at it wrong and a $70+ dollar repair bill, that was in the 80s. Firmware can be fixed but if the hardware is wrong, there is little you are going to do to correct it.
My normal use of a handheld meter is pretty basic. That's why I buy cheap, disposable meters for the garage. The 121GW would be out of place in that environment.
For potential buyers is important to know the switch longevity , but users can't do anything as you said ( besides beeing pissed >:()
So we concentrate on what can be changed , the firmware .
And without a mature firmware many switches will last for ever , who would use daily such a multimeter ?
I don't remember the exact count for our testing of the switch but I believe it was 40000. We did our range switch testing live on youtube.
Yea, I know Dave ran what he called his 50,000 cycle test on it, I watched.
No, he increased the autorange speed, Dave did a video about it, too:The same person pointed out one of the changes to the code that effected the filter and also found the code that had the logical error for the lead insertion test.
...
He has published everything in Github:
...
But you are right, probably not useful as the base for a fully open source version. But the circuit diagram is open source, so someone could develop a cleanroom implementation of an open source firmware for it. Shouldn't be too difficult, just a lot of work for all the functions the original firmware has.
Every multimeter has the advertised number of counts 4000 , 6000 , 50000 all the time and switches up and down above this value , lets say at 4400-4100 , 6600-6300 , 55000-52000 ...False, neither Fluke 87-V (https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg1829909/#msg1829909) nor (AFAICR) UNI-T 61D do that.
Pretty bad , I hope you don't want 121GW to copy the exceptions or slow meters with the hardware that it has ...
If the hysteresis is very big will eat some resolution because for a 50.000 count meter you can't use a giant up level like 65.000 just to have down level above 50.000 count .
I think I don't have to explain again that if you adjust a voltage up and down you will experience this loss of resolution .
Anyway the switching should be as seamless as possible , not this huge hysteresis and slowness that now the firmware has ... I don't think any user would want different or wouldn't care
[...] to copy the exceptions [...]I'm honestly interested to know which DMMs have a down-range threshold higher than the nominal target range as you have stated.
The big step in my opinion would be to make a firmware capable of "normal" autorange hysteresis in all modes - volts , amps , resistance and so on.
Every multimeter has the advertised number of counts 4000 , 6000 , 50000 all the time and switches up and down above this value , lets say at 4400-4100 , 6600-6300 , 55000-52000 ...
Hmm , almost all , if not all , multimeters with the microcontroller imbedded with the measurement chipset , old and new , even the cheapest chinese ones .Sorry missed this one. So it's not for certain EVERY meter as you first state. It's all or almost all.
Hmm , almost all , if not all , multimeters with the microcontroller imbedded with the measurement chipset , old and new , even the cheapest chinese ones . And the fast multimeters with separate microcontroller ... the extreme hysteresis that needs to go below the nominal counts is a clear indication for slow autoranging .
Metrix 3293, 10.0000 scale : going up at 9.9999, down at 09.900
Less than the Gossen mentioned, we're discussing now where different meters switch scales in auto. Not comparing other things..Metrix 3293, 10.0000 scale : going up at 9.9999, down at 09.900
And the price?
Metrix 3293, 10.0000 scale : going up at 9.9999, down at 09.900
34465A: 1.2 V up 1.0 V down:scared: Finally we got a winner! :scared:
From the 34401A manual
Resolution
Resolution is the numeric ratio of the maximum displayed value divided
by the minimum displayed value on a selected range. Resolution is
often expressed in percent, parts-per-million (ppm), counts, or bits.
For example, a 6 1⁄2-digit multimeter with 20% overrange capability can
display a measurement with up to 1,200,000 counts of resolution.
This corresponds to about 0.0001% (1 ppm) of full scale, or 21 bits
including the sign bit. All four specifications are equivalent
But before I placed my order, I did want to confirm that there is no new hardware version imminent, like, shipping the day after I get the current version delivered, lol.
I realize that firmware updates are an ongoing thing, but I would just hate to miss out on hardware version 2.0 or whatever by a few weeks and end up with "old stock" (although I realize that getting in on the first run of any manufacturing version has its risks).
But before I placed my order, I did want to confirm that there is no new hardware version imminent, like, shipping the day after I get the current version delivered, lol.
I realize that firmware updates are an ongoing thing, but I would just hate to miss out on hardware version 2.0 or whatever by a few weeks and end up with "old stock" (although I realize that getting in on the first run of any manufacturing version has its risks).
Nope, no new v2.0 hardware coming any time soon. There is a new PCB layout to integrate the current mods that has supposedly been done, but I have not even seen a prototype of that yet. I wouldn't really call it a V2 meter.
Get the firmware sorted on Git so we have some control of it is the big thing we want to do.
Time (s), Temp (°C)
0, 37.8
0.486785, 37.6
1.512485, 37.6
1.999798, 37.6
2.487146, 37.6
2.973385, 37.6
3.460483, 37.6
3.996788, 37.6
4.483994, 37.6
4.971935, 37.6
5.460796, 37.6
........
Had a proper play with the autorange resistance switching with V1.58 Beta and had a play with the bluetooth/app I haven't used for a while. Both have improved :-+
Disaster of all disasters it selected 0.4998 k \$\Omega\$ on one occasion instead of the 500.12 \$\Omega\$ it selected on another (34401A 500.034) ::)
Circa 25C data for comparison 500 \$\Omega\$ 500.04 121GW 500.017 34401A
Improving the time coding of the bluetooth data recorded straight off the app might be nice 0.5, 1.0, 1.5 ..... :) Currently over 40C in the shack makes it :popcorn: o'clock.QuoteTime (s), Temp (°C)
0, 37.8
0.486785, 37.6
1.512485, 37.6
1.999798, 37.6
2.487146, 37.6
2.973385, 37.6
3.460483, 37.6
3.996788, 37.6
4.483994, 37.6
4.971935, 37.6
5.460796, 37.6
........
3 decimal places would probably also be sufficient >:DLOL definitely. but I'd prefer leave that up to the end user.
3 decimal places would probably also be sufficient >:DLOL definitely. but I'd prefer leave that up to the end user.
From standpoint of standardization, it's not acceptable to have two different sources or owners of a document. Usually, the intellectual owner of the DMM should also be the owner / author of the document.So you are saying that manual writing cannot be outsourced? Or be done in collaboration?
'Seppy' seems to represent that role, currently.
If he would hand over the full responsibility and also the latest source code of the document (vers. from 8th Feb. 2019), it would be ok.
The alternative document currently contains a lot of old errors, is partly incomplete, and is in a premature state.Did you read the full post from EEVBlog? He stated that it is based on an older revision currently and that it is not finished. I assume if there are enough yays, and the design and readability issues are ironed out, that it will be updated to the latest revision and checked and corrected by EEVBlog and Seppy.
So I decline this document, as nice it may look on the first few pages.You can keep using the original.
From standpoint of standardization, it's not acceptable to have two different sources or owners of a document. Usually, the intellectual owner of the DMM should also be the owner / author of the document.So you are saying that manual writing cannot be outsourced? Or be done in collaboration?
'Seppy' seems to represent that role, currently.
If he would hand over the full responsibility and also the latest source code of the document (vers. from 8th Feb. 2019), it would be ok.QuoteThe alternative document currently contains a lot of old errors, is partly incomplete, and is in a premature state.Did you read the full post from EEVBlog? He stated that it is based on an older revision currently and that it is not finished. I assume if there are enough yays, and the design and readability issues are ironed out, that it will be updated to the latest revision and checked and corrected by EEVBlog and Seppy.QuoteSo I decline this document, as nice it may look on the first few pages.You can keep using the original.
I for my part like the new document very much. Although I agree with many other comments about readability. Grey is suboptimal. The design overall get’s a big plus from me. A professional meter needs a professional looking manual, not one that look’s like it’s made in a copyshop.
BR,
Michael
A user wrote a new version of the manual which looks much more professional:6 for original 1/2 dozen for new. I don't mind who does the manual but really like'd that errors and short comings could be posted in the issues thread and were responded to and incorporated where useful. Not sure why some of this guys ideas weren't just incorporated but can see why the feedback request.
...Feedback welcome.
KainkaLabs If you make another video, it would be good to see you rerun the VA test as well. When I looked at the prototype meter, there was a problem when using this mode. I think your are the first person to demo it. Basically, how you have connected it is what they show in the manual. However, when I looked at it, it seemed that the firmware did not account for the burden voltage. To get around this, I placed the meter's common point to the low side of the load, Vin to the other side of the load and the current back to the supply. Basically removing the burden from the voltage calculation. After I did this, the numbers would come out correctly. I will post a picture on to the main page I linked if you are not understanding.
Beginner question - I've been looking at the current measurement specs of the 121GW. The smallest DC A range is stated as 50uA^5.
What does this notation represent? I'm used to both engineering and scientific notation, but this stumped me a little. Does it literally mean 50^5uA = 312500000? I've never 'deep dived' into DMO specs before so it may be a common practise that I just haven't seen before. Thanks.
Isn’t the ^5 a footnote? I didn’t check. Just an idea.
DC A 50 µA5
...
5 This mode will use the x10 amplifier and may have additional offset error that should be REL’d out before measurement.
Is it by design that the resistance measurement in auto range is quite slow?
At times it is pretty annoying to wait for the read out.
Please stop defending this slow firmware , everybody ( including Dave ) knows that it must be improved .
People don't buy a pretty expensive meter to use it in manual range ... this is a bad joke :-DD . You can use it as you want but keep your precious advices for yourself .
Looks like Rodger repeated the test I ran with the VA mode. It's been almost two years since I posted the original video showing the problems and possible workarounds. At the time it caused a lot of confusion. Even Dave seemed lost and when the guy selling the product and testing the prototypes is not following, you have a problem. Maybe Rodger's testing will be presented in such a way that will be easier to understand.
https://www.youtube.com/channel/UCd8CdLp2bKP6Uv0jvdLdiRA (https://www.youtube.com/channel/UCd8CdLp2bKP6Uv0jvdLdiRA)
Please stop defending this slow firmware , everybody ( including Dave ) knows that it must be improved .
People don't buy a pretty expensive meter to use it in manual range ... this is a bad joke :-DD . You can use it as you want but keep your precious advices for yourself .
Wow we all just got just so burned by you throwing that Iced Soy 1/2 shot decaff Latte at us :-DD
Wow we all just got just so burned by you throwing that Iced Soy 1/2 shot decaff Latte at us :-DD
But he is right in this point. There is also no actual progress in the 1.58 beta firmware, Ohm measurements are still a pain with this meter.
Please stop defending this slow firmware , everybody ( including Dave ) knows that it must be improved .
People don't buy a pretty expensive meter to use it in manual range ... this is a bad joke :-DD . You can use it as you want but keep your precious advices for yourself .
Is it by design that the resistance measurement in auto range is quite slow?
At times it is pretty annoying to wait for the read out.
In this or any other meter, I don't use auto range unless I have absolutely no idea what range the expected value is in. I set the range to what my expectations are. If it goes out of range, I revert to auto range. If one is debugging something - there is not such a thing as autorange that is fast enough though some are faster than others. ALSO - if you are measuring without a really good contact on what you are testing (this is what the sharp plated probes are for) OR there are charges in capacitors or the circuit is energized in some way, then it could autorange forever because the circuit is changing. That's why oscilloscopes are useful. Keep in mind that for any number of reasons, the meter might be seeing different values from moment to moment.
Please stop defending this slow firmware , everybody ( including Dave ) knows that it must be improved .
People don't buy a pretty expensive meter to use it in manual range ... this is a bad joke :-DD . You can use it as you want but keep your precious advices for yourself .
Here is an idea - please stop going on and on making the same point over and over and over - without anything actually useful. If you stop why would anyone respond to your junk if you are not writing it? Everybody does not know it must be improved - so don't write what actually is false. It's not "pretty expensive". It's actually about average. It's not a bad joke - your posts are. Practice What you preach except your "advices" are not precious, useful or wanted - so keep them to yourself.
I'm going to assume that after all this time if the speed of the 121GW could be drastically improved, they would have done it already. There are hints of this being the case in some other forum posts I found. Maybe someone could make an official statement and clear the air...
I'm going to assume that after all this time if the speed of the 121GW could be drastically improved, they would have done it already. There are hints of this being the case in some other forum posts I found. Maybe someone could make an official statement and clear the air...
I have a problem that when attempts were made to speed up the resistance range the auto-ranging become less reliable. Therefore if fast and reliable is not to be achieved, I prefer slow and reliable over fast and unreliable.
I would rather the developers ignore the shouts of "Faster! Faster!" and try to make the thing actually work...
So you're saying if you had a meter that could auto range nearly instantly, you still wouldn't use it that way? I find that hard to believe. It's going to be slower to have to constantly cycle through the ranges especially if there is only one button to do so.
You state that the meter could see different values. Isn't that the entire point of having the auto range feature? It seems like you are hurting your argument. Auto ranging was a great advancement along with DMMs.
Thanks for showing the video from Kainka Labs and also joeqsmith for his suggestion how to connect the 121GW in VA mode to avoid the problem of wrong VA readings.
Just for fun I did the same test with the Gossen Metrahit Energy. Same setup as in the video, 1V source, resistor 22 Ohm. The Gossen is connected as it should, gnd to gnd, voltage input to the +1V output of the source and the current input is connected to the resistor, the resistor is connected to 1V source.
The result is shown at picture 1 :-+
Then I changed GND and current input at the Gossen. Result is picture 2. 8)
That means that the Gossen meter uses the same wiring in the power mode which joeqsmith suggested for the 121GW.
I did some experiments on power measurement with the 121GW and I observed the "correct" way to connect it to measure power consumed by a load resulted in a negative display value for the power.
At first I didn't like this, but actually you could argue that power consumed is negative and power produced is positive. So perhaps it is just a matter of human perspective rather than any technical limitation of the system?
Metrix MTX3293 actually shows negative VA in secondary VA mode... For instance it will show 5V, -100mA and -500mVA..
But it will be correct.
I just DLed the manual for this meter. Interesting enough, they don't provide many details for the VxA mode. There are no recommendations on how to connect it that I saw and there was no mention about the burden voltage when using this mode. I then looked for a video showing it but I only found one. The guy really doesn't provide any details other than to say how nice he thought it was. Is there an application note or better manual available for this meter?
That switch has been a nagging thing keeping me from buying.
That switch has been a nagging thing keeping me from buying.
Dave,
I just watched the latest mailbag. You mention a new version of the 121GW and working towards getting your rotary switch life cycle tester working again. I plan to do a full review of this meter which would include cycling the switch. If you are interested, I would be be willing to buy a couple of these meters now (assuming you are happy with the other changes to the hardware) and run the test for you.
It would be the 50K full cycle test like I have been running. It would be non-stop unless something were to go wrong and I decided to abort the test.
What's the max safe temperature for the K-type temperature probe provided with the meter?
Manual says 1350 C, but that's about the probe itself.
What about the coating of the probe wiring?
Sorry if I missed this but is the voltage and current for continuity test listed somewhere?
Someone is telling me that an STM32 can be damaged by DMM continuity checks...
For the 121GW I couldn't find it in the manual, but see this page:
https://lygte-info.dk/review/DMMEEVBlog%20121GW%20UK.html
2.1 V open and 0.57 mA shorted.
I'm hoping the eevblog team are on holidays, I broke a probe tip 12 days ago, emailed them that same day and I haven't heard back from the team on how to replace it, fingers crossed they will come back rested and send me a response.
I bought the 121GW because it looked promising (and it is) but also because of some other points:
- heavily supported by Dave
- upgradable/hackable
- Dave's enthusiasm
Now, it seems that the "soufflé est retombé" as we say in French. I would like to be proven the opposite, but except a few apparitions of the multi-meter in some videos, enthusiasm seems to be gone, upgrades are no longer available, no more reaction from any Dave.
Available resources have probably moved to the micro supply ... until the next project ? May a small team support several projects and keep enthusiasm for all of them?
No offense at all, only my feeling... Buying the GW121 was my own decision, it's working, I use it and I don't regret it. I was just hoping a bit more.
What were you expecting? Personally I feel the firmware is likely approaching the limits of the hardware so incremental change will naturally slow and be minor in nature.
So my question: where is the enthusiasm of the beginning gone ? May be a subjective feeling.At the beginning, there was an air of excitement, interest and critical assessment of various aspects of a new meter. Much of that has now produced a more refined product which does not have as many "issues". As a more mature product, it will - like every other - slide down people's scale of enthusiasm and settle into a typically mundane "workhorse" status.
But as I said, the multi-meter is doing its job, I use it and don't regret it.That's where this meter's evolution sits right now for a great many owners. The boring, everyday workhorse.
I seem to remember it has happened before that more recently bought 121gw’s had newer FW than what was available at eevblog.com. Perhaps just the way the communication goes - it might not be the same person who sends new FW to the factory who also sends it to Dave.The official FW is produced by the factory. They have "secret sauce" routines which they are coy about sharing. Dave would get it after the factory has released it.
I bought the 121GW because it looked promising (and it is) but also because of some other points:
...
Now, it seems that the "soufflé est retombé" as we say in French. I would like to be proven the opposite, but except a few apparitions of the multi-meter in some videos, enthusiasm seems to be gone, upgrades are no longer available, no more reaction from any Dave.
Available resources have probably moved to the micro supply ... until the next project ? May a small team support several projects and keep enthusiasm for all of them?
No offense at all, only my feeling... Buying the GW121 was my own decision, it's working, I use it and I don't regret it. I was just hoping a bit more.
I received a letter with title "EEVblog 121GW Stock Clearance!". Initially I thought this may mean the dmm is approaching EOL, but I don't want to speculate. Anyway, for those who interested, check this out: "Use the coupon code fluxcapacitor in the checkout for 20% off the meter, and if you like, the carry case as well."
I received a letter with title "EEVblog 121GW Stock Clearance!". Initially I thought this may mean the dmm is approaching EOL, but I don't want to speculate. Anyway, for those who interested, check this out: "Use the coupon code fluxcapacitor in the checkout for 20% off the meter, and if you like, the carry case as well."
To get the shelf empty it would help to put firmware version 1.61 onto the download page.
I received a letter with title "EEVblog 121GW Stock Clearance!". Initially I thought this may mean the dmm is approaching EOL, but I don't want to speculate. Anyway, for those who interested, check this out: "Use the coupon code fluxcapacitor in the checkout for 20% off the meter, and if you like, the carry case as well."
Yeah, I got the same email about 20% off stock clearance!
I'm guessing a revised 121GW is about to be released or its all over for the meter which has had extremely short shelf life if thats the case.
Hopefully its a revision of the meter and one that fulfills its initial promise of being a fast responding and unique electronics focused meter.
I get the feeling all will be revealed soon!
I'm surprised nobody has managed to pull it of the microSD card :) *hint* *hint*
I'm surprised nobody has managed to pull it of the microSD card :) *hint* *hint*
AFAIK, It is not on the SD card in the *as shipped* condition - brand new.
Certainly was not on mine.
My guess is that Dave has stock on his shelves that needs to be turned into cash. Stock on the shelf doesn't do anything but tie up capital. It needs to be sold and new stock ordered for any business to survive.
My suspicion is that people have been hanging back, waiting for all the "problems" to be ironed out and that's taken the edge off the interest in this meter. From what I've read, it seems that a lot has been sorted out, so there's no real reason for people with an interest to wait any longer.
A promotion with a discount is a pretty common way to attract sales - so if anyone was hesitating, I'd say now is a good time to pull the trigger.
To get the shelf empty it would help to put firmware version 1.61 onto the download page.
I received a letter with title "EEVblog 121GW Stock Clearance!". Initially I thought this may mean the dmm is approaching EOL, but I don't want to speculate.
My guess is that Dave has stock on his shelves that needs to be turned into cash. Stock on the shelf doesn't do anything but tie up capital. It needs to be sold and new stock ordered for any business to survive.
Now, it seems that the "soufflé est retombé" as we say in French. I would like to be proven the opposite, but except a few apparitions of the multi-meter in some videos, enthusiasm seems to be gone, upgrades are no longer available, no more reaction from any Dave.
After Dave's comments about reviving the toggle bot to repeat the switch life cycle testing, I offered to buy a couple of the new meters and run that test for them but no response and I have not heard anything else.
I guess you'll finally be buying one these then Brumby!!!!!!!!!
Perhaps not? As you seem to know all Dave's intentions for this meter, both present and future, if you resist this bargain 20% off deal then maybe your holding off for a revised model?
My guess is that Dave has stock on his shelves that needs to be turned into cash. Stock on the shelf doesn't do anything but tie up capital. It needs to be sold and new stock ordered for any business to survive.
Correct. I talked about this on the Amp hour the other month. I have to buy a lot of meters in one hit, and it's a huge amount of money, the last lot (plus other things) practically wiped out the companies cash reserve. So much so that I had to stop paying myself wages.
Not surprising to anyone with half an idea of how small business is challenged on a daily basis. I don't have any secret communications, just common sense (sometimes :D ).
It's just a meter, there was some excitement because it was a kickstarter, but now it's a year and half later and it's now just another product in my store. That was inevitable.
I'm using 2.00 firmware at present and UEI have said we can release it, so expect it soon."is good news :)
Fixes are still coming. I'm using 2.00 firmware at present and UEI have said we can release it, so expect it soon. Improvements are better and faster resistance and capacitance autoranging.
Could someone please share calibration data? I lost it while messing up with the meter and not all ranges I can calibrate (like I don't have a high-voltage source for AC, for example). I know results won't be perfect, but it's fine :)
I'm in no rush.After Dave's comments about reviving the toggle bot to repeat the switch life cycle testing, I offered to buy a couple of the new meters and run that test for them but no response and I have not heard anything else.
If I had a spare new thicker PCB meter to send you, I would.
Not surprising to anyone with half an idea of how small business is challenged on a daily basis. I don't have any secret communications, just common sense (sometimes :D ).
Or people could just listen to The Amp Hour ;D
Does anyone have any idea on how to source replacement probes?
Now, it seems that the "soufflé est retombé" as we say in French. I would like to be proven the opposite, but except a few apparitions of the multi-meter in some videos, enthusiasm seems to be gone, upgrades are no longer available, no more reaction from any Dave.
What "enthusiasm" do you want?
Want me to include an outro in every video plugging the meter?
It's just a meter, there was some excitement because it was a kickstarter, but now it's a year and half later and it's now just another product in my store. That was inevitable.
Fixes are still coming. I'm using 2.00 firmware at present and UEI have said we can release it, so expect it soon. Improvements are better and faster resistance and capacitance autoranging.
"Low Z" is typically meant for "ghost voltage" on mains.But wouldn't it make sense to allow it to be used for other things like testing batteries?
But wouldn't it make sense to allow it to be used for other things like testing batteries?Theoretically yes, but the current would be still pretty low for a battery. E.g. the Fluke 117 has ~3kOhm resitance in LoZ mode, so a 1.5V cell would cause a current of 500µA. That's probably not enough to be useful for battery testing.
In most high impedance "ghost" mains voltage cases isn't one more interested in measuring the current anyway (measure with a few kohm R in series so no chance you blow a fuse somewhere)?Ghost voltages are created by capacitive coupling (no current flowing). With the typical multi MOhm resistance, you can measure voltages like e.g. 75V that seem to be dangerous. When measuring in LoZ mode, the current over the e.g. 3kOhm resistor is enough for the ghost voltage to disappear.
just use normal voltage range.
You think that if you put AC across a capacitor no current flows?But wouldn't it make sense to allow it to be used for other things like testing batteries?Theoretically yes, but the current would be still pretty low for a battery. E.g. the Fluke 117 has ~3kOhm resitance in LoZ mode, so a 1.5V cell would cause a current of 500µA. That's probably not enough to be useful for battery testing.In most high impedance "ghost" mains voltage cases isn't one more interested in measuring the current anyway (measure with a few kohm R in series so no chance you blow a fuse somewhere)?Ghost voltages are created by capacitive coupling (no current flowing). With the typical multi MOhm resistance, you can measure voltages like e.g. 75V that seem to be dangerous. When measuring in LoZ mode, the current over the e.g. 3kOhm resistor is enough for the ghost voltage to disappear.
just use normal voltage range.
You think that if you put AC across a capacitor no current flows?Let's not start nitpicking. It's quite obvious that I intended to explain that ghost voltages are not caused by inductive coupling (i.e. through a current) but by capacitive coupling.
I thought we were all engineers in here.I thought we were here to help each other, not to be smarty-pants.
You think that if you put AC across a capacitor no current flows?
I thought we were all engineers in here.This is not helpful.
LoZ is for AC and DC . When "engineering minds" work in real world will find many situations when a voltage in a circuit looks OK with a tipical high impedance multimeter , but it's not actually , because there is a fault and the circuit is just capacitive coupled or there is some high resistance conductive dirt somewhere ... For this is LoZ .
For example in a car circuit , you should check with LoZ or a light bulb if the fuses are OK , if not , a blown fuse can leave some conductive traces and you would be fooled with a normal multimeter .
You think that if you put AC across a capacitor no current flows?
You seem to be missing some basics here...
For the ghost voltage situation, putting a DMM with a 10M (or higher) input impedance across it is not going to load the voltage down a lot. You could easily measure 100VAC which might prompt you to start chasing down a fault that simply does not exist. The simple answer is to put an appropriate load across the measured points and then read off the voltage. Know your load and know your voltage means you know your current.
What is of most interest here is not the actual current that flows but the voltage you read when the circuit is under this load.
So why is it AC only on the 121GW ?
Most interest? Why? The rules and regulations about how much leakage is safe quote currents not voltages across some vaguely defined non linear load.
That's odd. Mine showed nothing on a 6V battery.
So why is it AC only on the 121GW ?
Why do you believe it is AC only?
My 121GW have no problems showing DC voltage in LowZ mode.
That's odd. Mine showed nothing on a 6V battery.
Why do you believe it is AC only?
My 121GW have no problems showing DC voltage in LowZ mode.
It's totally bizarre.That's odd. Mine showed nothing on a 6V battery.
Why do you believe it is AC only?
My 121GW have no problems showing DC voltage in LowZ mode.
You need about 12VDC before the meter will show anything (In my opinion this is a silly detail).
This actually works for single NiMh cells but there's not much of a difference compared to the high ohmic mode - which (as stated before) is not really to be expected with a ~500µA load current.
Even cheaper if you pay with crypto!How is the price with cryptocoins?
Dear Sir or Madam,
We have been informed by Kane Test that some of the shipped EVBlog 121GW multimeters have an issue. This can result in a loss of calibration data after a firmware update. Unfortunately, this issue cannot be resolved by the customer.
Please check if your 121GW has a serial number in the range of 190106323 .. 190106450.
If this is the case:
- Do NOT attempt to update the firmware on your 121GW.
- Do NOT yet send the device back to us. We will arrange an exchange once we receive new stock from Kane Test in about 3-4 weeks.
- Please let us know the serial number of your device, and if you agree in exchanging your affected 121GW with a new device.
If your 121GW is not in the noted serial number range, you do not need to worry and can ignore this e-mail.
Thank you for your cooperation!
Best regards,
Your Welectron Team
Please check if your 121GW has a serial number in the range of 190106323 .. 190106450.
Even cheaper if you pay with crypto!How is the price with cryptocoins?
Conversion from price in AUD using the rate at time of purchase?
Just got this below from Welectron here in Europe so maybe Dave should make a note of the serial range on the firmware page if he publishes the newer firmware.QuoteDear Sir or Madam,
We have been informed by Kane Test that some of the shipped EVBlog 121GW multimeters have an issue. This can result in a loss of calibration data after a firmware update. Unfortunately, this issue cannot be resolved by the customer.
Please check if your 121GW has a serial number in the range of 190106323 .. 190106450.
If this is the case:
- Do NOT attempt to update the firmware on your 121GW.
- Do NOT yet send the device back to us. We will arrange an exchange once we receive new stock from Kane Test in about 3-4 weeks.
- Please let us know the serial number of your device, and if you agree in exchanging your affected 121GW with a new device.
If your 121GW is not in the noted serial number range, you do not need to worry and can ignore this e-mail.
Thank you for your cooperation!
Best regards,
Your Welectron Team
When I changed the firmware on the prototype Dave sent, it had to be realigned. I assume it was because they changed the format (locations, size, types....).
It's totally bizarre.That's odd. Mine showed nothing on a 6V battery.
Why do you believe it is AC only?
My 121GW have no problems showing DC voltage in LowZ mode.
You need about 12VDC before the meter will show anything (In my opinion this is a silly detail).
Sent from my SM-N9005 using Tapatalk
Fixes are still coming. I'm using 2.00 firmware at present and UEI have said we can release it, so expect it soon. Improvements are better and faster resistance and capacitance autoranging.
My guess is that there is a problem with V2.0 otherwise it would be released!Fixes are still coming. I'm using 2.00 firmware at present and UEI have said we can release it, so expect it soon. Improvements are better and faster resistance and capacitance autoranging.
Any news about the new 2.0 firmware?
My guess is that there is a problem with V2.0 otherwise it would be released!
Why withhold an improvement that would benefit users? Can only be a problem was found and its pointless releasing a buggy version.
It's just a meter, there was some excitement because it was a kickstarter, but now it's a year and half later and it's now just another product in my store. That was inevitable.
The new firmware will come one day or another :)
My guess is that there is a problem with V2.0 otherwise it would be released!
Why withhold an improvement that would benefit users? Can only be a problem was found and its pointless releasing a buggy version.
That is a very doubtful explanation, new meters has for some time been delivered with newer software than is available on the website.
Sorry I thought David had put v2.00 on the website, I've just added it now.Thanks!
Improvements include improved resistance autoranging speed, and update speed on higher resistance ranges. Plus various capacitance range improvements.
Hi,
the ohm autorange is faster now, still not my fastest multimeter, but it is ok.
The "low capacitance bug" seems still present, a 220pF NP0 ceramic capacitor is shown as 0.160nF at the first time, then as 0.180nF after that as 0.200nF... The more often I switch the meter off and on, the closer the reading comes to the actual value. Also if I first read the small capacity, then a bigger one (e.g. several hundred nF) and then again the small capacity, the 121GW every time shows a different reading. I am not able to get a steady reading of small capacities with the 121GW. Can other users reproduce this behavior? This is really odd. For higher capacitances the meter shows correct values and the autorange speed seems also faster in capacitance mode now.
Anyone wondering if they should bother to update firmware to V2.0?Indeed. I agree.
My advice for what its worth is to do it! The update certainly speeds up the meter's responsiveness for resistance and gives it a faster feel all round.
I did it successfully but there is a "Gotcha" in this. The .bin file is named EEVBlog2_00.bin. That name will not upload into the meter. Rename it to EEVBlog.bin, as it has been in the past and the upload will work.
EEVBlog folks may wish to repost the 2.0 zip with the .bin file name modified to avoid confusion and match past releases.Please, no.
Suggestion for 2.0+ is to not display "Douun" if the meter could not find a file to load, either because it was not the correct name (as here) or some other reason. It should post something like "Err" and then restart after a few seconds.That's not a bad idea.
I did it successfully but there is a "Gotcha" in this. The .bin file is named EEVBlog2_00.bin. That name will not upload into the meter. Rename it to EEVBlog.bin, as it has been in the past and the upload will work.
I wouldn't call this a "Gotcha". This has been a requirement from the very beginning.
I would strongly suggest that you always keep the firmware showing the version number in the filename and ONLY change it when copied to the card for uploading.
My recommendation: NEVER, EVER, EVER put up a file named EEVBlog.bin here or anywhere else - because you won't know what version it is.
That's not unreasonable, but it does put a greater risk of getting it wrong when the firmware is zipped by Dave/David.
I'm happier with the fail safe method currently in use. When things go wrong now - no damage is done and is fixed by a simple rename.
QuoteSuggestion for 2.0+ is to not display "Douun" if the meter could not find a file to load, either because it was not the correct name (as here) or some other reason. It should post something like "Err" and then restart after a few seconds.That's not a bad idea.
They have no way to reprogram the boot loader?
Hi,
the ohm autorange is faster now, still not my fastest multimeter, but it is ok.
The "low capacitance bug" seems still present, a 220pF NP0 ceramic capacitor is shown as 0.160nF at the first time, then as 0.180nF after that as 0.200nF... The more often I switch the meter off and on, the closer the reading comes to the actual value. Also if I first use a small capacity, then a bigger one (e.g. several hundred nF) and then again the small capacity, the 121GW every time shows a different reading. I am not able to get a steady reading of small capacities with the 121GW. Can other users reproduce this behavior? This is really odd. For higher capacitances the meter shows correct values and the autorange speed seems also faster in capacitance mode now.
It would be good if somebody could do another side by side comparison video to show how much better this meter performs now with the new firmware.
https://www.youtube.com/watch?v=q4gXnpFPFzQ (https://www.youtube.com/watch?v=q4gXnpFPFzQ)
Some resistance ranges are still affected by noise , probably where the ADC is at the maximum sensitivity . Overall the measurement current is too small on all ranges if you compare it with a known brand multimeter and this force the ADC to be very sensitive and easily capturing any noise from the hands holding the probes . It would be fantastic if in real world we would measure resistors like in the video , without holding the probes .
Thanks, I will have a look at that video shortly. :)
I just found this video on Youtube where someone has created a splendid addition to the tilt stand on the 121GW meter. :-/O
I was thinking they could reprogram the boot from some other means
I think I may have bricked my meter. I downloaded the V2 firmware, extracted the file, renamed it, transferred it on to a different Micro SD card that I'd formatted in Windows 10, then put it in the meter and tried to update it. It's been sitting at IAP- douun for over half an hour now. Help!It should only take about 5 seconds.
Two hours after starting the upgrade it hadn't moved, so I took a deep breath turned it off and tried putting the new firmware on the original Micro SD. I put it in and tried uploading it and it worked, like you said - in less than 5 seconds. When I turn the meter on the backlight flashes briefly but it's done that since I upgraded to 1.57. I'll test the meter out later and hope like hell that I haven't shagged it. I was just trying to use a faster Micro SD. Oh well, we live and learn, and make dicks of ourselves.That all sounds normal again.
I had the same problem earlier today. Turns out you need to rename the file from EEVBlog2_00.bin to EEVBlog.bin
I was thinking they could reprogram the boot from some other means
No, and that's the whole point, so that the bootloaded is fully protected from idiot users.
In theory there should be no way you can crash the firmware upload and brick your meter, i.e. taking out the card during programming, or power interruption, or corrupted code etc.
I just say that some people would use it working on something ;D not just for show .
Now it is much better than it was with some old firmware , but still in some ranges last 2 digits will fluctuate .
Sorry if I spoil somebody sensation that this is the perfect meter .
I just say that some people would use it working on something ;D not just for show .
Now it is much better than it was with some old firmware , but still in some ranges last 2 digits will fluctuate .
Sorry if I spoil somebody sensation that this is the perfect meter .
I was thinking they could reprogram the boot from some other means
No, and that's the whole point, so that the bootloaded is fully protected from idiot users.
In theory there should be no way you can crash the firmware upload and brick your meter, i.e. taking out the card during programming, or power interruption, or corrupted code etc.
Perhaps your customers are just a bit overzealous causing them to experiment more than they should. After all, isn't that the jist of Don't Turn it on, Take it apart.
I just say that some people would use it working on something ;D not just for show .
Now it is much better than it was with some old firmware , but still in some ranges last 2 digits will fluctuate .
Sorry if I spoil somebody sensation that this is the perfect meter .
It is my everyday driver in my toolbag and works fine. It is you who has the problem, sell your meter and stop being a sook.
I just say that some people would use it working on something ;D not just for show .
Now it is much better than it was with some old firmware , but still in some ranges last 2 digits will fluctuate .
Sorry if I spoil somebody sensation that this is the perfect meter .
It is my everyday driver in my toolbag and works fine. It is you who has the problem, sell your meter and stop being a sook.
Hey BeanFlying, I believe CDaniel is entitled to share his opinion just as you and I am!
You like the meter and its in your tool bag thats cool.
CDaniel wants to criticize certain functions of the meter and how it operates thats cool too!
We even have one person in this thread who shares his opinion on this meter and he doesn't even own or have one. Thats amazingly cool as well!
No need to get your knickers in a knot over opinionated people because as we all know, everyone has one (IMO) :-+
I had the same problem earlier today. Turns out you need to rename the file from EEVBlog2_00.bin to EEVBlog.bin; that did the trick and it updated to V2 in only a few seconds. Had the same "oh crap" thought when the "down" display just sat there...took a chance and cycled the power and fortunately the boot loader didn't have a problem! :phew:
I just say that some people would use it working on something ;D not just for show .
Now it is much better than it was with some old firmware , but still in some ranges last 2 digits will fluctuate .
Sorry if I spoil somebody sensation that this is the perfect meter .
I just compared it to the Brymen BM869 and Keysight U1272A and they have exactly the same fluctuation when handling the leads, even worse perhaps, using the same 30M resistor with the same leads.
I didn't say it's the highest range ... the reading fluctuate in 5K range for example when you hold the probes .
OK , a video with a 47K , even with no touching hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right
https://streamable.com/giz9s
OK , a video with a 47K , even with no touching hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right
https://streamable.com/giz9s
OK , a video with a 47K , even with no touching hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).
I'm not sure why people hate this so much, I like to think it's a little exercise of the battery and the backlight every time.
Hi Dave, I wasn't having a whinge (apart from the back light flashing briefly when the meter turns on).
I'm not sure why people hate this so much, I like to think it's a little exercise of the battery and the backlight every time.
OK , a video with a 47K , even with no touching hands , just the bench noise . If I move the meter away from the table it is stable , but obviously something is not right
https://streamable.com/giz9s
That power outlet with USB power supply in it has a switch and wasn't turn on ;D
Nothing was turned on on the bench , just the normal electrical noise from the wires
I have just upgraded to v2 software and everything seems fine except I can't turn the backlight on anymore. is anyone else seeing this. Admittedly I have not used the backlight for a while so might not have been working before I upgraded the firmware.
This may be a silly question or already answered but I was wondering what this slot on the back of the rubber case is for, picture attached. Wasn't sure what to search to figure it out.
This may be a silly question or already answered but I was wondering what this slot on the back of the rubber case is for, picture attached. Wasn't sure what to search to figure it out.
Use the slot for something like this eBay auction: #132926318720 or I have been going to do something with 3D Printing and a good magnet but as I don't do much work is metal cabinets it isn't that important to me.
@chronos42Yes, I still get the light flash. Not sure if this is a intended feature or a short undefined state after power on, but I do not have any problem with this behaviour.
Mine works ok. Just curious, do you get the light flash when first turning on?
It fits UEI's magnetic hanger, but I don't actually sell that.
hello i have a question...
does 121GW multimeter have differential probe for measuring current? i want to measure current around more than 10 Amps on my device anyway
answer is really appreciated, thx before
It fits UEI's magnetic hanger, but I don't actually sell that.
This one, I assume:
https://www.ueitest.com/products/accessories/amh1 (https://www.ueitest.com/products/accessories/amh1)
It fits UEI's magnetic hanger, but I don't actually sell that.
This one, I assume:
https://www.ueitest.com/products/accessories/amh1 (https://www.ueitest.com/products/accessories/amh1)
Yep, I think that's the one.
Could probably make a little slide in adapter that took some sort of standard size magnet (say 10mm dia) and allowed it to fit snug inside.
hello i have a question...
does 121GW multimeter have differential probe for measuring current? i want to measure current around more than 10 Amps on my device anyway
answer is really appreciated, thx before
A differential probe for... current? What is your use case?
Without more information or your requirements (AC or DC? Contactless or resistive current measurement? Are the sources isolated?), the following methods may work.
Multiple 121GW meters can connect to an Android device or Windows PC via Bluetooth, and math functions can be performed against the connected meters. You could simply take the subtraction of the readings between two connected meters.
Resistive:Contactless:
- 2x 121GW meters (or any oscilloscope with simple math functions + some milliohm-scale power resistors)
- An Android device or Windows PC (if using the 121GW)
- 2x 121GW meters (or any oscilloscope with simple math functions)
- 2x hall-effect current sensors, such as the PDI CA-60 (https://smile.amazon.com/gp/product/B00X3GDVWM/)
- An Android device or Windows PC (if using the 121GW)
It may be more cost-effective (and offer greater insight) to use a cheap oscilloscope such as a Rigol DS1054Z than multiple 121GW meters. Depending on your requirements, you could also build a circuit to do this, and measure it with a single 121GW (or any other meter or oscilloscope).
But answer the specifically asked question: no, the 121GW doesn't have any differential probes.
Tweakage finished unless anyone who makes it finds an issue and I will see if it can be improved.
Hollowed out the release so it now has more flex, fattened up the front bar for more strength and short of hanging your toolbag on it shouldn't ever be a problem. Also increased the web at the rear of the release for more strength when being pressed. The release as it is here in PLA can be deflected down by about 3mm without any risk of breaking it and the urethane section of the bumper can easily be flipped over it then to release the hanger. Still recommend PETG if you have it (I will try one next time I have some loaded).
Print settings 6 layers all round 40% infill so basically solid at 0.2mm layers. Printed on edge with bed supports only, could fully support it but the one shown in this post wasn't. STL is in the Zip file attached here.
Hello,
an updated version (8th of August 2019) of the manual is online
Frank
Goto: https://www.eevblog.com/product/121gw/ (https://www.eevblog.com/product/121gw/) => documentation
08/08/2019
Added battery voltage check to the firmware update pro-
cedure.
2.00
Improved the Auto-ranging reading speed in both ca-
pacitance and resistance ranges.
1. Ensure the low battery indicator is not present.
See Battery Voltage, Page 60.
Looking at purchasing this. Mainly interested in the logging feature.
And you still have that signature ? :-//Looking at purchasing this. Mainly interested in the logging feature.
BLE logging is still very broken.
Looking at purchasing this. Mainly interested in the logging feature.
BLE logging is still very broken.
Broken isn't the right term but buggy is closer with the bluetooth. It has improved over the release version but would still benefit from more work on the app.
The logging data isn't where it should be as the 'precise timing' from the meter is bs and still needs fixing to something meaningful or sensible preferably at the meter end in firmware.
Precision, Accuracy etc are a matter of reference. You need to specify it to have a frame of reference. My biggest beef with the software/meter for logging is the BS timebase used not the 'accuracy' of the meter. The timebase can be post edited in a spreadsheet with a little maths but it shouldn't have to be.
Against my recently calibrated Keysight 34461A snd I haven't looked at recalibrating it against this and my in cal 34401A but it is well within the combined error margin of both.
Rough setup and plenty of possibilities for stray noise to play with the BT but looking for dropped results and NOPE.
30 minutes of logging with a rough setup as shown and lets look at the 'false recordings' and other random unsubstantiated claims of the Troll boy in chief - NOPE :palm:
I feel sorry for someone trying to research this meter for purchase. There is too much back and forth and these threads are ridiculous for trying to find the current status of the meter. I suppose an official page with all the firmware versions and known and fixed "concerns" listed out would be too much to ask for???
The manual has instructions for the firmware. The most recent manual is on the Meter's page on EEVBlog.com (https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=30207 (https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=30207))
I have to say that I was a bit surprised at the official support for this meter when I came looking. Dave being Dave, I assumed that he would've been fairly thorough in providing this (official updates, notifications etc). There isn't even a readme file attached to the firmware zip.
Dave did send out the updated rotary switch hardware to people who had received the original dial. If you need it and did not receive it, I guess you need to contact EEVBlog.
Also I just discovered that there is hardware (pcb?) upgrade to fix (I assume) the rotary dial issue? Has this change been rolled out to for sale units?
Anyhow perhaps I'm being a bit too critical as I don't know the history behind the meter.
Ok, so the firmware changes are explained in the manual. What about existing bugs? I don't think it is unreasonable to have a list of those. And I mean a concise list on the product page, not 50 pages of threads with people saying "I can't get this to work" ...If you do not own a meter, then you may not realize that it is actually a very good meter. It had some unique features such as a very low burden voltage for the current ranges.
I realise that a fix was released but I understood there was also a pcb upgrade as well?
I don't own a meter (yet), hence the questions.
The Bluetooth capability was added late in the design, I believe. It was not one of the primary design goals. It works, but not as robustly as some people would like. I have not used the logging myself yet - I use it as an accurate multimeter for the purpose of talking live readings. For me, it works great.
Lots of test hardware has bugs when you dig deep enough. You will see it all the time in Dave's reviews of new test and lab instruments.
What you have to understand with Dave's multimeter is it is not a multimeter made in the millions with a massive R&D budget.
Richard
It is just exceptionally boring to hear disappointment at the BLE endlessly. Dave and the meter company put a design together with BLE hardware as a late addition, and it turns out it doesn't work as well as some people want. It is not possible for Dave to wave a magic wand and have the BLE magically turned into a non-BLE Bluetooth interface.
It is the BLE feature that got me very interested in this device to begin with.
For people to find another meter we must tell here the meter fauts and bugs , so you are contradicting yourself like a fanboy .Name calling is a great way to end a conversation.
After all we don't care how and when the logging was added , just if it is working like it supose or not .
Of course there are another bugs , just the discusion is now shifted to logging .
For people to find another meter we must tell here its fauts and bugs , so you are contradicting yourself like a fanboy .
After all we don't care how and when the logging was added , just if it is working like it supose or not .
Of course there are another bugs , just the discusion is now shifted to logging .
Is posted enough evidence not to trust in logging , of course for fanboys never will be suficient . He made a 30min , one time logging ( I supose his only logging ever with this meter ) , and he thinks is "proving " that is ok ;D ;D ;D
I feel sorry for someone trying to research this meter for purchase. There is too much back and forth and these threads are ridiculous for trying to find the current status of the meter. I suppose an official page with all the firmware versions and known and fixed "concerns" listed out would be too much to ask for??? There really should be one page that lists out everything a 121GW owner (or potential owner) needs to know. For example, there are different hardware versions/updates, a recall of specific serial numbers, troubleshooting suggestions, etc....Yep, 121GW threads could be much better managed which should be a breeze as Dave and Seppy are administrators.
How about a new pinned thread with strict rules on new posts?Nope, they just need to clean up existing threads and lock one in which to make announcements and post links to all resources for 121GW.
It is just exceptionally boring to hear disappointment at the BLE endlessly.
As with all hardware, it is what it is. Just accept it. If it is not good enough for you, find another meter.
It is just exceptionally boring to hear disappointment at the BLE endlessly. Dave and the meter company put a design together with BLE hardware as a late addition, and it turns out it doesn't work as well as some people want. It is not possible for Dave to wave a magic wand and have the BLE magically turned into a non-BLE Bluetooth interface.
... and have to make do with the capabilities of that.
It is just exceptionally boring to hear disappointment at the BLE endlessly. Dave and the meter company put a design together with BLE hardware as a late addition, and it turns out it doesn't work as well as some people want. It is not possible for Dave to wave a magic wand and have the BLE magically turned into a non-BLE Bluetooth interface.
Correct. BLE was with hindsight a troublesome choice for some things. Full bluetooth would have been better, but unfortunately we are stuck with BLE and have to make do with the capabilities of that.
I ran fair number of tests using the proto's BLE interface with LabView. While the radio seems a bit weaker than the other two BLE meters I have looked at, it seemed to work alright with the firmware I was using.
I am not sure if I did much testing beyond 1.26, if at all. They were making changes to the filters during that time and I was running tests to evaluate them. The BLE interface wasn't working originally on the prototype meter, so I was using the card to log the data. Using the firmware supplied (pre 1.0 really early stuff), logging to the card would hang but once I had 1.0 loaded, it seemed fine. When I first started working with the BLE, I had some problems but discovered this was with my code, not the 121.
I ran fair number of tests using the proto's BLE interface with LabView. While the radio seems a bit weaker than the other two BLE meters I have looked at, it seemed to work alright with the firmware I was using.
Which I assume is v2.00?
I just ran into a bug with the Max hold function not displaying the correct range. Meter was displaying A, but the units were displaying as mA. I had to change the mode from DC -> AC -> DC to get it to resolve the problem.Probably best to copy this over to the EEVBLog 121GW Issues thread as its an issue worth reporting!
I think Joe will reveal the real issues with this meter once and for all. He has planned a number of vids and will be running one on firmware version differences. Facts and data are always appreciated along with his unbiased assessment.
Might put an end to the fanboy and troll comments this meter seems to attract?
Joe
The rotary switch contact holder has a 3 split shaft with little tangs that grab the back of the PCB. The height of these tabs minus the PCB thickness was probably what determined the compression of the contacts in the original design.
I think the idea of the shim was to provide more compression without having to remold the plastic contact holder.
You didn't measure the height of the tabs, but since the shim is still present one can conclude that the new meters ae same as old except with shim pre-installed.
The shim is not necessarily a bad idea, although a tolerance analysis of the resulting stack-up would surely prove otherwise, but maybe proper height tabs caused too much friction and subsequent debris or since the contact load is in a straight line perhaps the assembly would cock off axis which the shim would prevent.
The materials and the optimal contact preasure for long life shouldn't be "rocket sience" if you are in the industry , but ... when we see how difficult it is for them to do a decent firmware the trust is not very high .
I wrote this before several month:
"A 220pF NP0 ceramic capacitor is shown as 0.160nF at the first time, after switching off and on again as 0.180nF, after another power cycling as 0.200nF... The more often I switch the meter off and on, the closer the reading comes to the actual value. Also if I first use a small capacity, then a bigger one (e.g. several hundred nF) and then again the small capacity, the 121GW every time shows a different reading. I am not able to get a steady reading of small capacities with the 121GW."
This is one of the most weird issue I have ever seen with a multimeter. The fact that Joe's prototype seems not affected from this issue shows that this probably can't be fixed with a firmware update and is hardware related.
if it cannot measure pF then it will be useless for me... and if firmware update cannot fix this issue then looks like i need to sell my 121GW...seeing that even chinese cheap crap multimeters can measure pF range accurately really makes 121GW look like a stupid purchaseI think Joe will reveal the real issues with this meter once and for all. He has planned a number of vids and will be running one on firmware version differences. Facts and data are always appreciated along with his unbiased assessment.
Might put an end to the fanboy and troll comments this meter seems to attract?
That's a tall order!! :-DD :-DD
I wouldn't read too much into the unboxing video beyond that it does appear that the mechanical stack up between the prototype and production meters appears the same (except for the added preload caused by the shim). Not being able to read the 150pF was a bit of a surprise but I am sure I could add enough capacitance to the fixture to get the meter to read something, then null it out and try again. It's not like we have not seen this with other meters but I wouldn't have expected the 121 to be this far out.
I don't recall the prototype ever having problems reading a 1M resistor. Actually, I don't think I have seen ANY meter exhibiting a problem like this. After cycling the switch a few times, the readings continued to get tighter and I never saw the meter hunt like that again. It can be difficult to track down problems like this that are not reproducible.
Obviously the settling time has been a hot topic. I'm sure a few of you remember me posting a fair amount of data on the firmware changes to the filters which I expect was an attempt to get the meter to settle faster. I removed most of that data to help clean up the "issues" area. Personally, I will take slow, accurate measurements any day over fast inaccurate ones. While I had installed 1.57 in the prototype, I don't appear to have any notes about testing it. I suspect the upgrade was part of sorting out the BLE / LabView interface.
My plan is to dedicate one full segment just to the firmware. I plan to repeat my previous noise testing on the production meter which will include all the same firmware plus the latest versions. For now I will stay focused on the hardware differences between the current production meters and the prototype.
if it cannot measure pF then it will be useless for me... and if firmware update cannot fix this issue then looks like i need to sell my 121GW...seeing that even chinese cheap crap multimeters can measure pF range accurately really makes 121GW look like a stupid purchase
Maybe Dave can advise us all on what the current revision is for the meters and if he plans to sell a revised PCB to those who already have the meter?
A discounted replacement PCB for early adopters would be much appreciated! (Providing its actually an improvement of course).
Maybe Dave can advise us all on what the current revision is for the meters and if he plans to sell a revised PCB to those who already have the meter?
A discounted replacement PCB for early adopters would be much appreciated! (Providing its actually an improvement of course).
No plans for replacement boards to be made available, there is no functional difference, it's just a normal process of refining the design over time, happens regularly to all meters. Existing customers are not missing out on anything.
I brought this up when I bought my 121 GW and was steam rolled by the same people moaning now that the meter was great and upgrades meant nothing and the meter I got was the same as the revised ones so no different. In fact it wasn't new so it was no different yada yada yada....!
Too funny ;D
Maybe Dave can advise us all on what the current revision is for the meters and if he plans to sell a revised PCB to those who already have the meter?
A discounted replacement PCB for early adopters would be much appreciated! (Providing its actually an improvement of course).
No plans for replacement boards to be made available, there is no functional difference, it's just a normal process of refining the design over time, happens regularly to all meters. Existing customers are not missing out on anything.
Hey Dave it would be nice if you could provide an update on what hardware revisions the "most current" version of the 121GW has had installed.
It would also be appreciated to know what the revised hardware has been fitted to achieve in the meter's function or protection.
It seems the EEVBLog store is selling older versions of the 121GW meter as Joe Smith found with his latest purchase of 2 new meters from your store. Can you supply from your store the current version meter? Will you discount the old meters or continue to sell old revision meters at full price?
How about sending Joe Smith 2 current version meters so we can see the results of comprehensive and unbiased testing of the current 121GW meter!!!!!!!!!!!!!!!!!!!
You should read carefully what are the issues , use the meter some time and then tell us the conclusion .
I doubt your pF measurement is consistent and not drifting ...
The problem with the 50ohm range are the last 2 digits or so , for small resistors ... even when you short the leads the reading is very inconsistent .
All the meters are like yours with slow resistance autorange . The 50ohm range is not stable because they design it with very low measurement current and insanely high ADC gain . This can't be fixed in firmware .
So CDDaniel, you are basically telling me the Resistance mode of the 121GW is just plain bad? It does work okay, in manual resistance range. I just can't tell watch range I am in or when I cycle back to auto when pushing the range switch. It would be nice for some sort of easier to view enumerator was on the display. There is the "AUTO", but when range is pushed that goes away and I have no idea what range I am in, and NO, I am not reading the manual to know what ranges it toggles through. Why should I have to do that? Any other meter displays what range it is on! Okay maybe that bottom analog scale might show it?... It is hard to read. Why not put something where the AUTO is?\
I push Range many times and it does not go back to auto.
The issues I see with resistance mode
1 - slow autorange , this is improving with every firmware update
2 - in 50ohm range the last 2 digits are pretty useless . Every time you short the leads you get different reading and fluctuating .
3 - any range is more or less affected by mains noise , if you touch the probes . Of course this is subjective as some people have "quiet" labs , so for them is ok .
What J-R should maybe look at FIRST is what are the accuracy or tolerance of the Caps he is playing with and do his meters confirm that the combined accuracy is in the correct ballpark. You can test with as many meters as you like but without a 'known' starting point or some sort of reference all the readings are just relative to each other. Stating meter X is better than Y is :bullshit: without a reference or known standard to compare against. The best you can do is really give a best guess yeah or nay as to accuracy at the extremes of spec.
So CDDaniel, you are basically telling me the Resistance mode of the 121GW is just plain bad? It does work okay, in manual resistance range. I just can't tell watch range I am in or when I cycle back to auto when pushing the range switch. It would be nice for some sort of easier to view enumerator was on the display.
Hey Dave, or anyone from the EEVBlog Store!
Can you please make clear what version of the meter is currently in stock and being sold from EEVBlog Store.
Dave, how about a technical run down on what the latest hardware revision of the meter does and how the meter has changed over the period of time since it first went on sale!
It seems you provided heaps of great info on this meter initially, (pre-sales) and I for one found it interesting and informative.
The meter has a few problems and didn't live upto initial expectations, but I'm still interested as an owner and as an early adopter/supporter of your collaborative effort with UEI.
My wish is that you would come forward and update the buyers of this meter on just what progress has been made!
The worst thing IMHO is that you have become silent on the technical progress of this meter. Your silence and not keeping the community around this meter informed is damaging your reputation as an advocate for honest unbiased technical reviews.
Looking forward to hearing from you with an updated EEVBlog on the current state of play with the 121GW meter!
I wrote Dave today after he suggested that I "... should have asked first!" that it's really up to him to communicate with his customers, not the other way around.
In my case, the entire drama could have very easily been avoided with a simple note in the ad.
I suggest major revision as the PCB revision had changed and the shim had been removed, along with other changes. Any changes to that switch design IMO is major.
Hey Dave, or anyone from the EEVBlog Store!
Can you please make clear what version of the meter is currently in stock and being sold from EEVBlog Store.
In my case, the entire drama could have very easily been avoided with a simple note in the ad. Again, to be clear, I was never looking for special treatment. I want the meters that any one else placing an order would get. What I was not expecting was to find out that a newer major revision of the meter was available a few months before I bought mine and I received the old hardware, without notification. This is just bad business practice and pointing the finger at the customer is certainly not a step in the right direction. They are certainly free to handle their affairs as they see fit, but as a past customer it won't happen again.
Dave says there was no update to the published spec, so I don't quite see what's the ruckus...
...
On the other hand, I am wondering why spending time and money to change something that already meets specifications ? (except thickness of the PCB to avoid the patch)
...
But who said that newer meters behave better ? As far I can see my meter always could measure 150pF and Joe's newer version out of the box couldn't .
I'm wondering how is working now , has recovered itself ? In the latest video 1nF was close with the other meters , not 1nF - 150pF
This new build (v.02 -1910 PCB) is the first run after the 4000 Kickstarter boards were assembled, changes are (IIRC):
1) Correct 1.6mm PCB as intended (the KS PCB was unknowingly thinner from the manufacturer, hence the shim)
2) Plated hole on the knob
3) The protection transistors that were fitted onto small daughter boards are now integrated into the PCB.
4) Battery terminals are now smaller
5) Supplied with UEi silicone probes now instead of Brymen.
Hello Joe, I found your videos on YouTube; nice. Is the older board the reason, they were on sale on the EEVBLOG store verses getting them from another source with the newer board? Is there anything other than the board, switch and shielding?Thanks.
Shorting the leads together, then it taking 2.5 seconds to show something <0 ohms and then that reading <0 floating around and slowly raising to maybe .200 or .260 ohms over several more seconds is an issue if you are trying to trouble-shoot circuits that are low in resistance to begin with. The inability for the meter to settle down with shorted leads, make the REL button not applicable.
The manual mode does not have this issue, but my complaint with the manual mode, is that unless you spend mental energy on the meter verses the circuit you are working on, trying to figure out what range you are on is difficult, at least for me. I think a good fix would be to better enumerate the display to show what manual range you are on. There is one manual range (I think the second press of the range button), that floats around too. Most manual ranges are fast and stable, I just have a hard time figuring out what range I am on. Is it not a dot matrix display? Can not the firmware display whatever it needs to? Kindly rework the ohms display to make it easier to tell what manual range I am on, and I think the problem is fixed.
I am quite new here in the forum, but have read some in the multimeter thread regarding 121GW here and it seems there is a lot of error with it?
I wonder if I should order one, but became skeptical when I read the thread.
Sorry if this has been asked before, but would the 121GW be a good choice for automotive electrical and electronics?
I teach electronics to automotive technicians. They are in a stage that they can use a DMM to measure sensors etc with ease. I gave them 121GW to use for a change. After 5 minutes the wanted to break it. :D :D :D
Is it possible to silence the beep in continuity mode and use the screen flashing as an indicator?
Is it possible to silence the beep in continuity mode and use the screen flashing as an indicator?
17 units of the old kickstarter build stock left, 20% discount off the already sale price on the EEVblog website, coupon code fluxcapacitorWhat improvements are we missing out on if we choose to save by getting one of these old build 121GWs?
https://www.eevblog.com/product/121gw/ (https://www.eevblog.com/product/121gw/)
Is there any way to log data with this DMM in a stable way?
The hanging part has nothing to do with using the SD card and BLE at the same time. It happened before, but I don't remember the circumstances. I think it was again on VA, but I'm not sure.
You are right about the logging equipment, but the whole idea of buying this DMM is using it for it's special features - BT, SD logging, low burden voltage, and they all don't work reliably.
You should be aware that there are some major problems with the VA mode. This was seen with the prototype and 2+ years later has yet to be addressed. :palm:
You should be aware that there are some major problems with the VA mode. This was seen with the prototype and 2+ years later has yet to be addressed. :palm:
If you are talking about the adding of burden voltage - that's not a problem. Also it's only a problem if you want to measure load power. I am measuring power supply (in my case battery) power. Every measuring instrument has imperfections and as long as you know about them - you can workaround them. The problem however when it starts freezing - that's not a normal DMM flow, it's a bug.
But yes, I agree that reversing the current probes in VA mode should be in the manual - it's a nice idea how to measure load power better (not power out of the supply).
As I said before they underestimated the firmware complexity ... anyway for +2 years it's impossible that more than 2 guys worked at this ;D , or maybe one just stood and watched the other :--
With David2 now out of the picture, I doubt you will see much effort being put into the application side.
With David2 now out of the picture, I doubt you will see much effort being put into the application side.
That was never the plan. We got the app to a good refined working point and released it as fully open source software. If people want to improve upon it and add features they can, but we never had any plans to extend it ourselves beyond what it already is.
If this were true, you would not be posting here for help.
Why criticise the original plan? It's not as if Dave kept it secret. Besides, as Dave has stated, software isn't his forte.
All we need is for others who are better equipped to develop the App to take up the challenge. Then things can improve.
The app is not the biggest deal. If the firmware is working fine there will be someone to develop an app. If the firmware is not working there is no point of developing an app.
If this were true, you would not be posting here for help.
I'm not posting here for help. I'm reporting bugs.
Is there any way to log data with this DMM in a stable way?you were asking for help. My bad. There is a thread to report bugs.
https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2043871/#msg2043871 (https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2043871/#msg2043871)
https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2037994/#msg2037994 (https://www.eevblog.com/forum/blog/eevblog-1157-transistor-zener-clamp-circuit/msg2037994/#msg2037994)
Here are Dr Franks’s posts he made just after Dave released his video discussing the advantage of the double transistor zener type clamp, and that this now would be implemented in 121gw.
Now there’s nothing wrong with Dave’s video as such, I think he does a great job presenting it. But it’s very hard to see how Dr Frank could have made it any clearer that this clamp solution would not work as transients at +/- 25V now could reach U9 the HEF4053. Although it of course depends on exactly how you implemented this new clamp, U9 would have a very hard time handling these voltages. There were also quite a few other members in that thread voicing their concerns.
Still the clamp change went ahead and new HW revision of 121gw released, and it seems it‘s this revision Joe received with the two production meters he recently bought. And anyone following Joe’s videos knows exactly how well this new clamp worked.
Anyway, I guess this also is an example of the (broken) “information age” we now live in, but still it’s things like this that's really frustrating as a 121gw owner, seeing perfectly valid and detailed feedback not really be taking into account.
Maybe some guys here shouldn't be too super-critical, because they simply had too high expectancy upfront.
On the other hand, I would have expected that Joe might have re-engineered and analysed the actual protection circuit, either for confirmation or disproof of my findings .. instead he just did his brute-force / destructive tests on the 121GW.I had invested a fair amount of time looking at the prototype. It seems that most of what I pointed out was ignored. It really made no sense to revisit how to improve it yet again as based on past history, I already knew what the end result would be.
If you looked at those last couple of posts of that UL listed TPI meter I showed, there are no MOVs and the meter was easily damaged. I assume they don't need all the MOVs and fluff for UL be cause the meter does not need to be robust. It needs to be safe. This is the difference between what Frank is mentioning with following the standards. There are no robustness standards so rather than follow the safety standards, I branched out on my own to look at their robustness.
In the 121, it's anyone's guess what their goals were for robustness. I am guessing something along the lines of UNI-Tish was good enough. But they include the MOVs and basic parts.
So while they did make a change, they didn't consider the impact it would have on how robust the meter was. Or maybe they did and that was a very low priority. Your guess is as good as mine. One thing is certain is that it's now on par with many UNI-T products I have looked at.
If you looked at those last couple of posts of that UL listed TPI meter I showed, there are no MOVs and the meter was easily damaged. I assume they don't need all the MOVs and fluff for UL be cause the meter does not need to be robust. It needs to be safe. This is the difference between what Frank is mentioning with following the standards. There are no robustness standards so rather than follow the safety standards, I branched out on my own to look at their robustness.As we know UEi already changed the design again, now using transistors with a VEB0 at about 16V and that will clamp close to this voltage instead of 25V as your production 1-2 probably had. And as manufactures usually aren't changing their design just for the fun of it, they at least seems to be trying for some level of ‘robustness’.
In the 121, it's anyone's guess what their goals were for robustness. I am guessing something along the lines of UNI-Tish was good enough. But they include the MOVs and basic parts.
So while they did make a change, they didn't consider the impact it would have on how robust the meter was. Or maybe they did and that was a very low priority. Your guess is as good as mine. One thing is certain is that it's now on par with many UNI-T products I have looked at.
A basic robustness test I’ve seen Dave use a couple of times is to put mains 240VAC into whatever mode the mode switch can be placed in, perhaps for a couple of seconds or so. I do my damndest trying to avoid doing a “mistake” like that. But still not an unreasonable test to do and see if the meter survives. So in this scenario the meters clamps, PTC’s and other input series resistors have to cope with the stress resulting from about 340V peak to peak, there can of course be some nasty overlayed transients on top of that but unless you’re monitoring the VAC with a scope you have no clue if this is the case.
Anyway, I can’t really remember if Dave also did this test on the 121gw, but I think so, in its original configuration anyway with the 4007‘s. But has he also done it with the new clamp configuration i.e. to show that it’s just as robust as it was before. If it isn't perhaps mentioning this in the next user manual revision is a good idea.
A basic robustness test I’ve seen Dave use a couple of times is to put mains 240VAC into whatever mode the mode switch can be placed in, perhaps for a couple of seconds or so. I do my damndest trying to avoid doing a “mistake” like that. But still not an unreasonable test to do and see if the meter survives. So in this scenario the meters clamps, PTC’s and other input series resistors have to cope with the stress resulting from about 340V peak to peak, there can of course be some nasty overlayed transients on top of that but unless you’re monitoring the VAC with a scope you have no clue if this is the case.
Anyway, I can’t really remember if Dave also did this test on the 121gw, but I think so, in its original configuration anyway with the 4007‘s. But has he also done it with the new clamp configuration i.e. to show that it’s just as robust as it was before. If it isn't perhaps mentioning this in the next user manual revision is a good idea.
Yes, done that (245VAC) countless times on every design variant.
I also do +/-1100V DC and 1100V AC as well, but both of my high voltage supplies will go into current limit mode when the meter is on the ohms range.
Survives all this just fine.
No not really...
I’m just perplexed, like I think many 121gw owners are. Mostly perhaps as you mentioned by the lack of information.
And just to be clear I’m not trying to put any blame on Dave, I’ve no idea what deal he has with UEi, but I got a feeling he’s not really in a position to put any pressure on them or is free to release information as he pleases. And this seems to leave quite a gap between 121gw users and the manufacture.
But I am interested in what clamping solution can be used instead of the leaky 4007's. Perhaps specially selected TVS diodes could be an option after all.
No not really...
I’m just perplexed, like I think many 121gw owners are. Mostly perhaps as you mentioned by the lack of information.
And just to be clear I’m not trying to put any blame on Dave, I’ve no idea what deal he has with UEi, but I got a feeling he’s not really in a position to put any pressure on them or is free to release information as he pleases. And this seems to leave quite a gap between 121gw users and the manufacture.
But I am interested in what clamping solution can be used instead of the leaky 4007's. Perhaps specially selected TVS diodes could be an option after all.
probably dave cannot control that meter development at all and after all it is just a UEi meter with EEVBLOG logo sticking on it to make people belive that it is dave who designed it.. cmiiw
I had looked up the Intertek cert. Looks like more than UEi are involved.
I had looked up the Intertek cert. Looks like more than UEi are involved.
Kane own UEi and Finest.
The meter was designed and is manufactured by Finest in South Korea. UEi is basically the US brand they bought in 1992, and Finest is the Asian brand they recently acquired.
But with the 121gw and how it was presented I always got the impression UEi was the actual manufacture and responsible for the FW updates. But of course doesn’t really matter. But it would be interesting to know if the KS meters and the 121gw that's being sold now were manufactured in the same factories.
But with the 121gw and how it was presented I always got the impression UEi was the actual manufacture and responsible for the FW updates. But of course doesn’t really matter. But it would be interesting to know if the KS meters and the 121gw that's being sold now were manufactured in the same factories.
Yes, same factory.
I'm not sure why the fuss over this. Companies in this sort of industry often have lots of complex relationships with part ownerships and branding etc.
I can assure you that the design and manufacturing has always been and is still done in South Korea by (formally) Finest (Fine Instrument Co) who is now wholly owned by Kane Test. They don't really use the finest brand any more that I am aware of, legally it's "Kane Asia" and that's who my purchase orders go to.
http://kanetest.co.kr/contact/ (http://kanetest.co.kr/contact/)
My point of contact for the design is the former CEO of Finest Instruments who now works for Kane Asia.
UEi are also another brand of Kane Test, and that is the brand they wanted associated with publicly for the project from day one, but that's the extent of "UEi" involvement with this project.
A lot of UEi stuff used Finest as the OEM, while other UEi stuff is designed and made in the USA.
If you want to go deeper down the rabbit whole, Klein Tools owned (or did own?) 50% of UEi, and that's actually how this whole thing started, I was talking to the head designer at Klein tools and down the rabbit whole it went to eventually Finest. They are all intertwined.
No fuss. Just curious what their factory looked like to see what sort of capabilities they have.
The APP works 1/2 second, and closes immediately?This sounds like a crash, and definitely should not happen. Which version is this - the iOS or the Android version?
@DavidWC also any chance you'd be able to create a MacOS app for logging?
The ability to capture Logs is a must in your no doubt vast quantities of 'spare time' ;)
Also important will be the ability to clear the data from the log or trigger a start of logging. Not sure what is possible but maybe even optional logging against the devices clock instead of the meters?
The pinch zoom vertically works fairly well but having the option or being able to show from the start of logging stay on screen would be great too rather than continual scrolling. That is assuming I didn't find a pinch zoom for that option that already exists?
Hi DavidWC,
I'm on Android 9, and GSM is a Samsung Galaxy S8 ( SM-G950F )
If you have a relatively-recent Mac and can run Meteor on an iPhone, capturing the data in the app and then using AirDrop to send them to the Mac is only one extra step and relatively painless. That's how I do it now for my own data.
With David2 now out of the picture, I doubt you will see much effort being put into the application side.
That was never the plan. We got the app to a good refined working point and released it as fully open source software. If people want to improve upon it and add features they can, but we never had any plans to extend it ourselves beyond what it already is.
these routines represent a significant investment and have proven to be of great competitive valueDid you have any chance to see the code or speak with some UEi developers ? It would be interesting to know :)
Unfortunately, after so many releases, this is also my feeling: not very well written/tested firmware. How could you have no doubt that1. I am just passing on information that Dave has made public in the pastQuotethese routines represent a significant investment and have proven to be of great competitive valueDid you have any chance to see the code or speak with some UEi developers ? It would be interesting to know :)
Do we know who made and claimed this part of the DMM product making: "fully open source software" ? What sort of work ethic is it if no owners who supported the 121GW have NO access to the "fully open source software"?
It may be the most engineer-tested firmware around. We're all on it and report any issue.
I think it's an interesting situation to be able to have a meter around where so many engineers have a poke at, comment on, critique on. It's all in the open (except the code :) ).
I enjoy using the meter. All the public scrutiny, reviews, videos make it the most alive piece of test equipment on the desk.
And the fact that all the shortcomings are out in the open. Almost like my own life ;)
I had to use a microSD card, and well the only one around was in the 121GW :-X
I'm trying to update the firmware, but the process doesn't work anymore. I believe that it may be a formatting issue, I've tried fat32 & exfat but still doesn't update. What exactly should I be formatting the microSD card to
What did you rename the firmware file to? https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2952134/#msg2952134 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2952134/#msg2952134)
EEVblog.bin not EEVBlog.bin likely case will matter?
Do we know who made and claimed this part of the DMM product making: "fully open source software" ? What sort of work ethic is it if no owners who supported the 121GW have NO access to the "fully open source software"?
EEVblog.bin not EEVBlog.bin likely case will matter?Tried both, but same issue, so :-//
Some people have reported firmware update issues if their batteries are low.
I've tried searching but does the 121GW no longer come with a case? Just bought a new one from the official distributer over here and there wasn't one in the box, the meter was just wrapped in bubble wrap.......
Regarding getting logged data off the internal MicroSD card... why not make it possible to do a File Transfer over BT? This should address users physical accessibility issues. Tried a BT file transfer from Windows 10 PC but the 121GW ignores the "Receive a File" request. Is it an issue the software stack to implement this feature is beyond the hardware's capability?
I've tried searching but does the 121GW no longer come with a case? Just bought a new one from the official distributer over here and there wasn't one in the box, the meter was just wrapped in bubble wrap.......
The meter has never come standard with a case.
Regarding getting logged data off the internal MicroSD card... why not make it possible to do a File Transfer over BT? This should address users physical accessibility issues. Tried a BT file transfer from Windows 10 PC but the 121GW ignores the "Receive a File" request. Is it an issue the software stack to implement this feature is beyond the hardware's capability?
It was considered very early on back in the development but it was deemed to be too hard. IIRC it needed added support in the bootloader code, so I don't think it's even possible with just a firmware update.
Is this meter still available for sale in the US? I only found a couple of used ebay listings. Amazon says no stock.
Is there any issue with ordering directly from the site - customs holds etc.?
But what is showing when shorting leads ?
You seem to have the 121gw in Continuity mode and not in Ohms mode - Continuity can only measure up to 500.00 ohms.
You seem to have the 121gw in Continuity mode and not in Ohms mode - Continuity can only measure up to 500.00 ohms.
? I switch to ohms and it was the only resistance mode that came up. Do I have to change something else? That doesn't seem very intuitive. What tells you it's in continuity mode?
You seem to have the 121gw in Continuity mode and not in Ohms mode - Continuity can only measure up to 500.00 ohms.
? I switch to ohms and it was the only resistance mode that came up. Do I have to change something else? That doesn't seem very intuitive. What tells you it's in continuity mode?
Press the Mode button until is says AUTO in the top left and the Ohms symbol appears on the right.
NOTE: The current stock meter from this website is the latest pre-Kickstarter build that has the new PCB (doesn’t require the shim) and larger protection transistors fitted. It also comes with the UEi test leads instead of the Brymen test leads. These leads do not have banana tip adapters like the Brymen leads
Hi everyone,
I got a 121GW last month from the EEVblog website, and I have one question:
What is the difference between the currently-sold 121GW "pre-Kickstarter" model sold by EEVblog's website and the "normal" production one?
My PCB looks like it's 2019-09 dated...QuoteNOTE: The current stock meter from this website is the latest pre-Kickstarter build that has the new PCB (doesn’t require the shim) and larger protection transistors fitted. It also comes with the UEi test leads instead of the Brymen test leads. These leads do not have banana tip adapters like the Brymen leads
Err no. How do I zero the probes? On my Keighley there is a nice zero button. On the 121gw?The's a nice REL-Δ button.
To be honest I am less than impressed with the 121gw. An experienced engineer should not not to resort to the manual every time he wants to do something that is basically simple. I .... Snip
Ok it's not working again....
Unless I'm missing something obvious.
I have a 56K resistor with probes attached either side. First I'm measuring with a brilliant cheap multimeter the Owen B35T+. It measures the resistor at 56K5 which is confirmed using using Keithley 2100. Then I haven't changed anything at all but simply moved the probes from the Owen to the 121GW. The 121GW measures the value as...... well it doesn't even recognise there is a value. I then put the probes back into the Owen and it is measuring the same. All I get out of the 121GW is OF.L. Not good for a meter costing 10-15 times the amount.
What's happened to the "EEVblog 121GW Multimeter Issues" thread?
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues)
I get 404 error trying to access it.
What's happened to the "EEVblog 121GW Multimeter Issues" thread?
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues)
I get 404 error trying to access it.
I received this notification by email
"Topic removed: EEVblog 121GW Multimeter Issues
EEVblog Electronics Community Forum <do_not_reply@eevblog.com>
To:jack_daniels
Sat, Jul 25 at 7:53 AM
A topic you are watching has been removed by Simon.
Regards,
The EEVblog Electronics Community Forum Team."
That wouldn't make any sense - this thread (EEVBlog 121GW Discussion thread) was started after the KS meters had been delivered - and is more or less a continuation of this old thread: https://www.eevblog.com/forum/testgear/new-eevblog-branded-multimeter-coming/ (https://www.eevblog.com/forum/testgear/new-eevblog-branded-multimeter-coming/).I don't think there was any confusion about the purpose of the thread. Deleting it makes little sense to me.
The now missing issues thread was intended for reporting specific issues - sure there was some overlapping between the threads - but for the most part they served their purpose - and a possibility to report issues with less chance of it drowning in the general discussion around the meter.
I'm surprised Dave is closing off forum discussion on the meter's issues ...That is not certain.
What's happened to the "EEVblog 121GW Multimeter Issues" thread?
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues)
I get 404 error trying to access it.
Maybe you and another moderator saw the new similar post. One deleted the correct and the other the wrong one...
Somehow I had a feeling Gnif might have known his way around the database. :-+
I like his approach. ;D :-+ :-+Somehow I had a feeling Gnif might have known his way around the database. :-+
Manually tweaking the database is his preferred method for everything, he's a nerd ;D
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/msg2828400/#msg2828400 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-firmware-details/msg2828400/#msg2828400)Thanks for that, (of course) I did all that, but the problem was far simpler. I forgot to move the SD card into the meter :D
If you downloaded the firmware and its in a zip package, you have to unzip/uncompress the file first.
...
Someday, maybe someday they will add a timeout to the firmware update menu so it will error out after say 3 to 5 minutes????Which would have been super helpful in my case. But I think this is the built-in IAP code, so bootloader change, and remotely (via SD) not update-able? (update-able fine with st-link of course)
Looks like the post was removed.Yes, it has been.
Is there a discussion about the fact the 121GW is 99,999 count when in calibration mode?
From what Dave has said recently, I don't think even he can answer that at the moment. It appears there are supply issues with some of the components - which would make it difficult for even the manufacturer to give a date.
There might be a typo in the 121GW manual - the footnote (3) for 50mV DC probably also should apply to 50mV AC but here it refers to footnote (2)? which is not to be found.Thank you for sharing your observation on the potential typo.
There might be a typo in the 121GW manual - the footnote (3) for 50mV DC probably also should apply to 50mV AC but here it refers to footnote (2)? which is not to be found.Thank you for sharing your observation on the potential typo.
I now checked with the Fluke 289 manual: The requirement for rel mode and zeroing for 50 mV DC is mentioned there, too, but no requirement for rel mode for 50 mV AC.
So, the footnote 2 on page 17 of the 121GW manual is maybe not to be read as footnote 3.
Got a bit carried away and tested a pile of my DMMs [...]Thank you very much for your excellent analysis!
Don't blindly trust one DMM.This is a key point. If I had (besides budget) more room, I would get a Keysight 34465 bench meter and a good handheld DMM, say Fluke 287/289.
The inability of the 34401A and the 287 to display very low mV AC values surprised me a bit.Actually, the 287 does not meet its specifications with your observation that 0.150 mV 1 kHz is displayed as 0.
The mV relative mode statements in the manual makes no sense to me. If the zero calibration point is off far enough that you need to REL the meter before taking a measurement, then the final reading will be off as well. If you REL out noise/interference, same issue.
Don't blindly trust one DMM.This is a key point. If I had (besides budget) more room, I would get a Keysight 34465 bench meter and a good handheld DMM, say Fluke 287/289.
(Btw, the Flukes are here in Europe twice the price of the US market prices.)
I am interested in low voltage AC (down to a few mV) for some audio connected measurements.
Ideally, I would find a handheld DMM with the accuracy of the 34465, but this does not exist.
When I needed to measure sub mV Audio signals I built an external AC amplifier based on the OP37 opamp. [...] I don’t know if any such device exists ready to buy though.I have never soldered before, so I would have to buy it - if it is for sale.
Stick to good brands, like Littelfuse, Cooper Bussmann or Siba if you can, otherwise examine the datasheet carefully for compliance.
The manual recommends cryptically ASTM HV610.0.4 400 mA (600V) or HV620.0.4(1000V) A/500 mA current input fuse (sic)
Stick to good brands
This:Stick to good brands
Stick to good brands, like Littelfuse, Cooper Bussmann or Siba if you can, otherwise examine the datasheet carefully for compliance.
Hi all,
I received my 121GW today. I went to check the firmware and I see v2.04 is the highest listed on the 121GW firmware page, but the start screen on the DMM shows v2.05. Is this an error and I should flash 2.04, or is 2.05 real and just not listed yet?
Thanks.
Probably not listed yet. Check the contents of the microSD card. If you see a file named EEVBlog.bin, share it with us. :D :D :D
Alexander.
Hi all,
I received my 121GW today. I went to check the firmware and I see v2.04 is the highest listed on the 121GW firmware page, but the start screen on the DMM shows v2.05. Is this an error and I should flash 2.04, or is 2.05 real and just not listed yet?
Thanks.
Hi all,
I received my 121GW today. I went to check the firmware and I see v2.04 is the highest listed on the 121GW firmware page, but the start screen on the DMM shows v2.05. Is this an error and I should flash 2.04, or is 2.05 real and just not listed yet?
Thanks.
I don't have have 2.05, have asked Kane what the deal is.
I have new stock on the way soon, don't know what version they will have. I can only presume that you bought it from Welectron and they somehow have a newer version firmware.
I now have v2.05
They changed the low pass filter curve to better match the performance of the Fluke 289, which I guess they are using as a sort of reference.
And yes, this version was shipped to Welectron.
I now have v2.05is that the only update??
They changed the low pass filter curve to better match the performance of the Fluke 289, which I guess they are using as a sort of reference.
And yes, this version was shipped to Welectron.
Also got mine from electron today with 2.05. Also the yellow shim have been removed?
Does it always comes without probes? I thought it’s either Brymen or UEI probes.
Also got mine from electron today with 2.05. Also the yellow shim have been removed?
Yes, the shim was only for the first several thousand PCB's that had the wrong thickness.QuoteDoes it always comes without probes? I thought it’s either Brymen or UEI probes.
I don't have control over what Welectron sell, but Kane's standard FOB quote is without probes. If the distributor wants probes then they have to order them as a separate line item.
By default Welectron checks the box to include the probes when you hit the 121GW page, but you can uncheck it.
I have two 121GW units that came with shims. I removed it from both and have had zero issues. Perhaps after things wear it might be needed.
Yeah, just received 121GW 2 days ago, and the firmware reads 2.05, no idea if that's actually from Welectron, but I ordered it directly from EEVBlog shop online. Delivered to UK by DHL courier and it originated from Australia.
Thanks Dave for your reply. Can I ask what is the changelog for 2.05, please?
I now have v2.05
They changed the low pass filter curve to better match the performance of the Fluke 289, which I guess they are using as a sort of reference.
I don't know the full Story with the shim that some revisions needed because of a wrong pcb thickness, so:
Do i have to check if my meter needs the shim, or were no meters sold without that fix?
Yes I ordered a pack of "Bussman" fuses from China, strangely arrived same day as my order from EEVBlog Australian shop, the labels were identical to the blown 11A fuse Busman fuse I removed, but the fuse end caps did not have "Bussman" stamped and the cap crimping was not the same. The cap plating was also slightly dull and difficult to get a good low resistance contact with my meter leads, when I did a low ohms resistance check they all measured higher resistance than the fuses supply by the EEVBlog shop.Stick to good brands, like Littelfuse, Cooper Bussmann or Siba if you can, otherwise examine the datasheet carefully for compliance.
Beware of fakes on ebay and other places. Because of the very high potential margins on these, the market is awash with fakes.
Yes I ordered a pack of "Bussman" fuses from China, strangely arrived same day as my order from EEVBlog Australian shop, the labels were identical to the blown 11A fuse Busman fuse I removed, but the fuse end caps did not have "Bussman" stamped and the cap crimping was not the same. The cap plating was also slightly dull and difficult to get a good low resistance contact with my meter leads, when I did a low ohms resistance check they all measured higher resistance than the fuses supply by the EEVBlog shop.Stick to good brands, like Littelfuse, Cooper Bussmann or Siba if you can, otherwise examine the datasheet carefully for compliance.
Beware of fakes on ebay and other places. Because of the very high potential margins on these, the market is awash with fakes.
Thanks Dave for the much cheaper quality fuses. :)
What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...
Dave could easily create another board of EEVblog Products and shift all the threads there and sticky them or whatever.What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...
I've thought that for a while as well. I'm actually surprised that Dave didn't consider it when announcing the new Brymen meter. Then I thought it's a Brymen and is going to work.... :-DD
The TE thread is popular enough it stays on top so it also makes little sense to me.
Others threads also seem old and unmaintained and I wonder the same thing. What makes them worth being sticky? Seems like it would be reserved. Info for beginners and rules all make sense to me. Even a single sticky thread for each of the products Dave markets makes some sense to me, just for the advertisement.
Not a big deal to leave it. Dave's site anyway and I enjoy the free use of it. So, good job Dave!
What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...why?
What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...
Dave could easily create another board of EEVblog Products and shift all the threads there and sticky them or whatever.What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...
I've thought that for a while as well. I'm actually surprised that Dave didn't consider it when announcing the new Brymen meter. Then I thought it's a Brymen and is going to work.... :-DD
The TE thread is popular enough it stays on top so it also makes little sense to me.
Others threads also seem old and unmaintained and I wonder the same thing. What makes them worth being sticky? Seems like it would be reserved. Info for beginners and rules all make sense to me. Even a single sticky thread for each of the products Dave markets makes some sense to me, just for the advertisement.
Not a big deal to leave it. Dave's site anyway and I enjoy the free use of it. So, good job Dave!
Yeah well if you examine the current Products board structure there are a few options if you must move stuff around and stir up grumbles where certainly you could add a Specific Instruments board where you could also further divide it into brands.....EEVblog brand instruments too of course.Dave could easily create another board of EEVblog Products and shift all the threads there and sticky them or whatever.What does everybody think about unpinning the 121GW discussion threads? I love mine, but I think the topics have quieted down enough that maybe we don't need three (or even one) of them pinned anymore. Just a thought...
I've thought that for a while as well. I'm actually surprised that Dave didn't consider it when announcing the new Brymen meter. Then I thought it's a Brymen and is going to work.... :-DD
The TE thread is popular enough it stays on top so it also makes little sense to me.
Others threads also seem old and unmaintained and I wonder the same thing. What makes them worth being sticky? Seems like it would be reserved. Info for beginners and rules all make sense to me. Even a single sticky thread for each of the products Dave markets makes some sense to me, just for the advertisement.
Not a big deal to leave it. Dave's site anyway and I enjoy the free use of it. So, good job Dave!
Well that just lit up an idea. What if there was a Specific Instruments test equipment section where each instrument of note (say several pages is the trigger) got it's own thread and they are all stickied.
It could be an easy go-to section for specific much talked about instruments?
If an ok idea I could make this a specific poll test to see what the general response is?
I now have v2.05
I now have v2.05Any reason it's not on https://www.eevblog.com/product/121gw/ (https://www.eevblog.com/product/121gw/) ?
I really like my 121GW, but there is one annoying thing - using it with the bail is a bit unstable. Has anyone come up with an alternative solution, perhaps something we could 3D print? It the bail was a little bit wider, I think it would go a long way for improving the (mechanical) stability.
I really like my 121GW, but there is one annoying thing - using it with the bail is a bit unstable. Has anyone come up with an alternative solution, perhaps something we could 3D print? It the bail was a little bit wider, I think it would go a long way for improving the (mechanical) stability.
v81,
Since this may become an issue I'll start. SN EEVBlog 001421 is ok.
How about little feature for next FW update?
VCO!
Many times i was not able to look at screen but need to tune something to the maximum value without being able to look at the screen!
So to have piezo inside multimeter producing sound that would change frequency with value change (i .e. voltage goes up, frequency as tone pitch goes up)
That way you can hook up multimeter to measure certain value, and while you are away, multimeter produces tone that pitches up or down while you are adjusting something, also resetting with delta function can set "new start" or create baseline pitch that will be your baseline (440Hz? idk).
Basically Like voltage controlled oscillator (VCO)!
It would be best to tie that to fast barograph display, or what I'm trying to say, the faster the better!
What is the opinion on this one? :popcorn:
The issue isn't the full capacity of NiMH which only manage to get to about 5.9V with the four in series immediately after charging. Within a few days it drops to approx 5.5 volts, then gradually drops to 5V over ~4 months of use. The meter will continue to work properly below 5V but that isn't good for the NiMH to go much below 1.25V assuming they are all even and I remember to check them.
Earlier in this thread people talk about mods or not for Li-whatever. They have the high side issue. I don't think their worth the cost or hassle.
Thanks, I will have a look at that video shortly. :)
I just found this video on Youtube where someone has created a splendid addition to the tilt stand on the 121GW meter. :-/O
https://www.thingiverse.com/thing:3666409 (https://www.thingiverse.com/thing:3666409) :-+
https://www.youtube.com/watch?v=vZ2xE71g_xw (https://www.youtube.com/watch?v=vZ2xE71g_xw)
Ran into a small issue with my unit, or rather the bag I purchased alongside it. The stitching along the lower edge of the front came apart for no apparent reason. It seems like the fabric panel that makes up the front was cut too short, and the stitching simply pulled out of the weave. I tried emailing the store support email listed on the EEVBlog contact page a month back, but never received a reply. I purchased from Welectron, is this something I'd have to reach out to them for, instead?
Yes, you'll have to talk to Welectron. I do not sell the case, nor do I provide the meters to Welectron, they order directly from Kane Test.
groan from the seasoned tech vets
Hi all,
Regarding the firmware update procedure for the 121GW.
I have read the words in the manual but am still unsure of the exact procedure.
So, do I need an additional SD card to the one installed in the meter to load the new firmware? What capacity SD card? There is no mention of this in the manual.
My laptop does not have an MSD card slot, so how do I install the file on the card?
I realise these questions may induce a groan from the seasoned tech vets on here but I am just not very familiar with this stuff ???
Yes, you'll have to talk to Welectron. I do not sell the case, nor do I provide the meters to Welectron, they order directly from Kane Test.
Much appreciated, Dave! I'll reach out to them and see what they say.
Hi,
I found it is not possible to report an issue on the store page here:
https://www.eevblog.com/product/121gw/ (https://www.eevblog.com/product/121gw/)
Hence have an issue to report.
According to the current version of the manual, the thermocouple reading cannot be calibrated.
One simple way of doing it is to use boiling/freezing water.
Capture the max temp when you put a K-type probe into your home boiler, make sure it does not touch the bottom where the heater is and you have the first point.
Water with ice would be the second one. Put water with lots of ice, wait. Make sure the probe end-tip does not touch the ice and capture the lowest value.
Is that a good idea?
Best
To some degree (no pun intended ;D ) there is not a huge need to try and 'calibrate' the meter with a K type thermocouple. 'Roughly Checking the Calibration' is about all you can do with your method.
Generally accepted accuracies Type K ±2.20C or ±0.75%
While the 121GW's spec is less than that Temp °C, -200 to 1350°C, K-Type, 0.1°C (resolution), ±0.5%+3°C (stated accuracy)
So inherently because of this you can not get a reading more 'accurate' or known under the spec of the meter. The Meter if it was to be calibrated on the Temperature range would more likely be done against a calibrated source instead.
I purchased a 121GW brand new from the official store (https://www.eevblog.com/product/121gw/) in Jan. 2023, and I then downloaded the Meteor app (https://apps.apple.com/us/app/meteor-for-121gw/id1452124710) for my iPhone. It works well enough via Bluetooth communication, but I wanted to compare with the official 121GW iOS app here (https://iphone.apkpure.com/121gw/121gw.ios). Sadly, it says Not Available regardless of whether I am signed in with my Apple ID for the USA or my other Apple ID for Japan. Is it region locked to Australia (which would be crazy)? Or is the official app totally dead on iOS for some reason?
The reason I even ask is because I dislike the Meteor app because it lacks a FREEZE/HOLD feature. When logging data with the app via Bluetooth, I want to be able to tap the iPhone screen or a button in the app to freeze the waveform display so I can better examine it. If I stop logging, the frustrating Meteor app dims out the waveform display, making it harder to see! I wanted to download the official 121GW app to see if it works better than Meteor in that regard. But again, I can't find the iOS official app anywhere now in 2023!
I purchased a 121GW brand new from the official store (https://www.eevblog.com/product/121gw/) in Jan. 2023, and I then downloaded the Meteor app (https://apps.apple.com/us/app/meteor-for-121gw/id1452124710) for my iPhone. It works well enough via Bluetooth communication, but I wanted to compare with the official 121GW iOS app here (https://iphone.apkpure.com/121gw/121gw.ios). Sadly, it says Not Available regardless of whether I am signed in with my Apple ID for the USA or my other Apple ID for Japan. Is it region locked to Australia (which would be crazy)? Or is the official app totally dead on iOS for some reason?
The reason I even ask is because I dislike the Meteor app because it lacks a FREEZE/HOLD feature. When logging data with the app via Bluetooth, I want to be able to tap the iPhone screen or a button in the app to freeze the waveform display so I can better examine it. If I stop logging, the frustrating Meteor app dims out the waveform display, making it harder to see! I wanted to download the official 121GW app to see if it works better than Meteor in that regard. But again, I can't find the iOS official app anywhere now in 2023!
I didn't do anything with the IOS app, it hasn't changed since the original release, so AFAIK should still be available. I don't have an iPhone so I can't check.
Before you get too excited about the original app know that the 'HOLD' feature only holds the text value. The graph continues to scroll.
I have the app on a 2015 iphone6 with ios12. It still works as originally.
121GW does not show up in the app store because unfortunately apple while claiming to be environmentally sensitive has determined that this phone is too old for them to allow updates to the latest ios16. They want users to trash their perfectly fine phones and buy new ones.
Since Seppy doesn't even own an iPhone he is not a likely candidate to update the app. It would be nice and perhaps help sales of 121GW if Seppy posted the source code on GitHub so others could update the app. I don't understand why Dave doesn't make it so.
Since Seppy doesn't even own an iPhone he is not a likely candidate to update the app. It would be nice and perhaps help sales of 121GW if Seppy posted the source code on GitHub so others could update the app. I don't understand why Dave doesn't make it so.
121GW does not show up in the app store because unfortunately apple while claiming to be environmentally sensitive has determined that this phone is too old for them to allow updates to the latest ios16. They want users to trash their perfectly fine phones and buy new ones.
In defence of [Apple culling older apps incompatible with new iOS releases], the overhead maintaining multiple O/S compatibility in an App is not insignificant - and is often impossible with new features only available with newer operating systems.
And so, I do hope that whatever happens now will bring us a better iOS app. Meteor (https://apps.apple.com/us/app/meteor-for-121gw/id1452124710) isn't all that bad, but not being able to FREEZE the waveform on my iPhone's screen (without dimming) is a critically important feature that I am totally shocked and amazed that the developer of Meteor didn't consider. It would be great if that developer could read our discussion here, as that may inspire him to improve his app, thereby making my call for the official app to be reinstated to the iOS App Store moot.
(snip....)
The reason I even ask is because I dislike the Meteor app because it lacks a FREEZE/HOLD feature. When logging data with the app via Bluetooth, I want to be able to tap the iPhone screen or a button in the app to freeze the waveform display so I can better examine it. If I stop logging, the frustrating Meteor app dims out the waveform display, making it harder to see!
After spending half the day and live stream trying to do it, thesource code is now on github:
https://github.com/EEVblog/121GW-App-Apple-IOS (https://github.com/EEVblog/121GW-App-Apple-IOS)
also gitlab:
https://gitlab.com/eevblog/eevblog-121gw-app-for-apple-ios (https://gitlab.com/eevblog/eevblog-121gw-app-for-apple-ios)
I don't know what @JDW was talking about unless a newer version of this existed at one time. (Attachment Link)
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2314242/#msg2314242 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2314242/#msg2314242)
(Attachment Link)
Thanks again for posting these. After spending a full day to figure out, both seem to be for the asci encoded version of the 121GW ble protocol (from 2016 b4 the kickstarter?) so won't work. The IOS version(don't know about android) is called 'Smart Data Logger' and appears to be the long lost version mentioned here:
https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2314242/#msg2314242 (https://www.eevblog.com/forum/testgear/eevblog-121gw-multimeter-issues/msg2314242/#msg2314242)
This is a screendump of 'EEVBlog Smart Data Logger', build 1.0.5 with startup screen data.
(Attachment Link)
Any thing newer?
I don't know what @JDW was talking about unless a newer version of this existed at one time.
This is a screendump of a working version of 121GW, build 1.7, loaded from app store around 2019 I have which doesn't do data logging.
(Attachment Link)
(1) Why does the backlight flash on & off for a split second each and every time I switch on my 121GW? I see no practical reason for that. It's not like you need to TEST the backlight LEDs each time the meter is switched on. And while it comes on too briefly to have a negative impact on the alkaline batteries, the fact remains it does draw more current in that brief split second versus the backlight not flashing on/off at all. Can it be said that is something which should be fixed in firmware?Actually, I had a 121GW where the backlight failed. It was a small SMD resistor that had cracked in half on the board containing the backlight LEDs (somewhat easy fix). So having the backlight flash is a good test and that is what made me notice it. But this may simply be what happens when power initially flows through the board. Either way, this is just not an issue that needs to be fixed.
(2) After switching the meter on, I want to know why it takes 3 seconds before I can use it. Sure, I see it displays the firmware version for 3 seconds. But does the meter deliberately wait 3 seconds solely for the purpose of displaying the firmware revision? Or would the meter take that long to become usable even if the firmware version was not displayed? The reason I ask is because if the meter could become usable faster than 3 seconds after switch-on, that would be beneficial, and perhaps the firmware version could be looked up somewhere in Setup instead of displaying every time the meter is switched on.A lot of DMMs display something before they are usable, for various reasons, most likely the DMM simply needs that long to start up so might as well show something on the screen. Given how many dozens of different firmware versions the 121GW has gone through, showing it at power on is a good place for it.
Why does any of this matter? Because (1) the 121GW has BlueTooth for some good reason, right? And (2) it's a bother to remove the blue bumper and unscrew the back case each and every time you want to access data logged to the SD card. I'm very glad that SD card exists, but disassembly is required to use it. No disassembly is required to use BlueTooth and a smartphone app, however! Hence my posts on that topic.
There is also Sigrok support:Why does any of this matter? Because (1) the 121GW has BlueTooth for some good reason, right? And (2) it's a bother to remove the blue bumper and unscrew the back case each and every time you want to access data logged to the SD card. I'm very glad that SD card exists, but disassembly is required to use it. No disassembly is required to use BlueTooth and a smartphone app, however! Hence my posts on that topic.
Many products have app issues over their lifetime, it is a fact of life now. Best to just move on. The 121GW actually has it pretty good, with the official Android and Windows app still available and working, and recently someone put together some code to data log via Linux:
https://www.eevblog.com/forum/testgear/121gw-multimeter-command-line-data-logger-for-linux/ (https://www.eevblog.com/forum/testgear/121gw-multimeter-command-line-data-logger-for-linux/)
Many products have app issues over their lifetime, it is a fact of life now. Best to just move on. The 121GW actually has it pretty good, with the official Android and Windows app still available and working...
It should be trivial to pick up a basic Android tablet or an old PC for Windows/Linux.
...I think it's safe to say the only users who can honestly avoid shaming these days is Linux users...
OK, sure, I can tell you that neither the Windows nor Android apps appear to allow you to "freeze" the "waveform". Also, I don't think I would call it a waveform, just a graph/plot. It only updates about once per second and is cumulative. It also continues to graph even when you press Hold (the last value is used for subsequent data points).
The graph in the app can't be stopped, you can only reset it. Although any time the mode/selector dial is changed such that the units change, the graph is reset.
...For now, after reading your feedback on the official app, it seems Meteor has an edge over the official app.Certainly that makes sense, otherwise I'm not sure why they would make it!
BTW, someone just told me the iOS code I uploaded the other day is the KaneTest one instead of the official 121GW app :palm:
I'll have to check and correct this.
BTW, someone just told me the iOS code I uploaded the other day is the KaneTest one instead of the official 121GW app :palm:
I'll have to check and correct this.
I took a quick look at the GitLab hosted 121GW App source code linked earlier, and it is a Visual Studio Xamarin/UWP app with targets for Windows, Android, and iOS.
I am not sure if the iOS support in there is complete, but loading it in VS2022 gave too many errors for me to deal with right now. Maybe someone with a bit more experience can try before I get another chance.
I use VS2022 to do some cross platform (Android & Windows) dev, but not targetting iPhone. I do have a Mac Studio where I maintain some older Objective C iPhone apps, but I'm far from an expert.
This is the latest and last official EEVblog 121GW cross-platform Visual Studio Xamarin/UWP app for Android, Windows, and Apple iOS targets.
i just had received my 121 GW Multimeter when I stumbled over the newest commit in the gitlab for the 121GW's Multiplatform App:
User Dave added to the Readme File:QuoteThis is the latest and last official EEVblog 121GW cross-platform Visual Studio Xamarin/UWP app for Android, Windows, and Apple iOS targets.
So what does that mean? Is the 121GW phasing out? Or is it just the App development, that is discontinued? Is there any official statement?
Hi all,
Regarding the firmware update procedure for the 121GW.
I have read the words in the manual but am still unsure of the exact procedure.
So, do I need an additional SD card to the one installed in the meter to load the new firmware? What capacity SD card? There is no mention of this in the manual.
My laptop does not have an MSD card slot, so how do I install the file on the card?
I realise these questions may induce a groan from the seasoned tech vets on here but I am just not very familiar with this stuff ???
except for the thickness, i absolutely love the size of this meter.
except for the thickness, i absolutely love the size of this meter.
The original design was thinner and used AAA batteries. But for better battery life we decided on a thicker AA design.
but i do have a chromebook and an android tablet and i see there are at least two apps which support the meter, so i'll try them out for times i need a bigger display.Please let us know if Android or Windows apps allow you to set the Interval timing because Meteor does not. Meteor sadly seems to lock the interval to a fixed 500ms/sample (approximate). Bluetooth logging seems to ignore the meter's "ln" interval setting entirely. That wouldn't be an issue if the app allows you to change the interval, but I see now way to do that in the Meteor app. That's why I am curious if the Android or Windows apps do allow changing the interval, and if not, what their fixed interval is between samples.
...when i started meteor for the first time i was supremely annoyed that it just started logging automatically and it literally took me 20 minutes to go through every menu item and to realize that to keep it from doing that i had to set the sample size to zero. :)
21:07:37.536, 52.950, 0, V
21:07:38.048, 53.462, 0, V
21:07:39.036, 54.450, 0, V
21:07:39.547, 54.960, 0, V
21:07:40.056, 55.470, 0, V
21:07:40.535, 55.949, 0, V
Just to let everyone know, the reason for all this discussion is because I am doing prep work for a YouTube video review of the 121GW. It was not given to me. I purchased it new at the end of January this year, direct from the EEVBlog store.
I just made my 121GW review video public here...
https://youtu.be/1iqURp-NsdM
I just made my 121GW review video public here...
https://youtu.be/1iqURp-NsdM
Took me a minute to realise you didn't have a green screen here!
Your lighting is amazing, what are you using? Do you have a studio tour video?
Many products have app issues over their lifetime, it is a fact of life now. Best to just move on. The 121GW actually has it pretty good, with the official Android and Windows app still available and working...
Once upon a time, most engineering software was exclusive to Windows, and there was a lot of shaming that took place when it came to engineers who preferred Apple hardware, even to the extent that many who embraced Windows called into question the engineering credentials of those who preferred the Mac. But in recent years Apple product adoption has increased to the level that even Microchip decided to make a MacOS version of MPLAB X. People in the engineering world are a tiny bit friendlier to Mac users, which is a nice break from the past. And that has been great for folks like me who are Mac and iOS users exclusively when it comes to machines I used privately at home. Even at work, I've moved my ProMate 3 from an old WinXP machine to my iMac, since MPLAB is on MacOS now.
So when I read something is considered "pretty good" ONLY BECAUSE it has "official Android and Windows apps", I am compelled to chuckle and whisper to myself — that doesn't help me! :-)
But like I said, the Meteor app exists for iOS, and that DOES help me; and I will continue to use it, along with the SD card for data logging. I am merely saying that if Meteor could be improved by way of adding a FREEZE button that freezes the currently logged waveform without frustratingly dimming the screen content, that would be outstanding for iOS users like myself (and I doubt I am the only one). And, if the release of the official iOS app's source code leads to it coming back to the App store AND offering a different set of features than Meteor, all the better!
I wish to humbly that @EEVblog for having investing the time to reply and make source code publicly available, for those (other than myself) who could possibly make productive use of it, for the good of all 121GW users.
lol in contrast to me, every single apple products are the last thing i want to touch in the world...but everyone has different preference after all ;DiOS running Windows... Too funny.
btw why don't you try using VM for iOs and smuview?? if your iOs is good then it should have no problem running windows or linux VM anyway
You cannot add "121GW Multimeter" to the cart because the product is out of stock.
Some EEVblog store products are also available from Simon's Electronics in the UK, Welectron in Germany, and Amazon in the US and Australia.
Didn't Dave or someone mention recently that the 121GW was discontinued or soon to be?
Dave,
I was contacted by a viewer of my 121GW review video who says he cannot order the meter from your product page (https://www.eevblog.com/product/121gw/). I just checked. Pretty crazy. Says 2 in stock, but when you try to add to your Cart you can't. Why? Because it then says this:
QuoteSome EEVblog store products are also available from Simon's Electronics in the UK, Welectron in Germany, and Amazon in the US and Australia.
"Amazon in the US" is not accurate. I just checked. Says UNAVAILABLE.
If you want one right now, Welectron has 9 in stock: https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth (https://www.welectron.com/EEVBlog-121GW-Data-Logging-Multimeter-with-Bluetooth)
Hi. I am the person who intended to purchase 121GW accessing your store from Japan After watching a thoroughly comprehensive review by fellow Japan resident youTuber, JDW.
Is the UT61E listing maybe just be his way of doing an affiliate/click-through? Seems like it will be drop shipped direct from China rather than through Dave in Australia.
Didn't Dave or someone mention recently that the 121GW was discontinued or soon to be?
Curious you seem to be asking that question to either myself or GraXXoR, when it's rather clear that neither one of us are aware of any mention of product discontinuation. You didn't even link to any post citing discontinuation. And as you said, the website has not been updated, still showing inventory, which makes no sense if a product has been discontinued.
I do still have some stock left, and have ordered some more stock due late Jan. But Kane have advised that they are basically using up their remaining stock of parts, and I get the vibe that once that's done they might not want to make it any more.
Sorry about the problems, I've actually moved to a new store website, so try that.
https://eevblog.store/products/121gw-multimeter
I am updating the purchase links in the text description under my 121GW Review video now, Dave. But even though I see the FUSE PACK on your new shop site, it has been out of stock for at least a year and as long as I can remember. And news about availability?
https://eevblog.store/products/multimeter-fuse-pack
Same issue with the Soft Case for 121GW too:
https://eevblog.store/products/bm235-121gw-case
Hi there there seems to be some confusion about what issue I’m having here.
The thing is I go through the entire shopping process added to my cart, it does actually seem to be in stock…. And once I’ve added it to my cart I go to the PayPal checkout and then I enter my business address or use the one register with my PayPal (home address) and then it says that it cannot be shipped to my country.
However there is still a pay button underneath it which seems a bit odd considering it can’t be shipped and I don’t want to press it.
I have attached the error message which I am receiving.
My address is central Tokyo.
Message sent. Let me know if the system is having a problem handling my address...
Don't let paypal do the conversion, 29,000 JPY is $203.56 USD at current exchange rates.
You'll almost certainly have to pay local tax and likely DHL brokerage fee on top of that yes (guessing $10-15 USD but I can't find any references for your country).
Sanway PC7000 is probably a fine meter, but does not datalog, do power measurement, low burden, etc. So not quite the same feature class. But yes due to low yen its going to make more sense to purchase locally.
The PC7000 is basically the same as Brymen BM867 including computer connection.
No. It’s not PayPal doing the conversion. It’s Shopify. They are charging ¥29,000. PayPal have a decent rate right now ¥134 per dollar. This is slightly better than the current ¥140 per dollar standard.
When you use PayPal’s considerate rate of exchange then based on Shopify’s Price, Reverse calculated to usd you get $214.
Am I misunderstanding? I believe the shop has determined the Yen price of the product... 29,000 Yen is far too neat and tidy to be a dynamic translation of $204.
Go to the store again today as I suggested above, you'll see the price has changed to the current days exchange rate, rounded to 100 JPY.
No one is going in and manually setting a price in a hundred different currencies.
Correct. All my store prices are set in AUD for a stupid reason to do with Shopify (I'd prefer USD, as I buy all my stock in USD), and any other displayed currency is Shopify doing the conversion automatically. I have no idea where it gets the conversion data from.Yes, that is what I suspected. Shopify is converting to Yen when I could be purchasing it in Dollars since I have funds in both currencies.
Use the coupon code orderofmagnitude for 10% off.
Is there a way to apply the code to my order?
Any help much appreciated.
I already wanted to discard the tips, but had a closer look, as the tip needle could somehow be rotated inside the rubber grips.
To my big joy, the grips can be pulled downwards, if you carefully grab the tips with a pliers at the thread.
This also raises the question, are new tips available from Brymen? I have two sets of those leads, one is perfect (I owned that from new...) but the other is heavily scarred (came with an abused bench meter I bought) and could use fresh tips.
Silicone Test Leads with vergoldeten Testspitzen und aufschraubbaren Bananensteckern, 1000V CAT IV, 10A
My function switch has become flaky and I need to know if the shim and replacement knob are still available and, if so, where do I get them. I was part of the original Kickstarter project and my meter was one from the 2nd production batch. (I received it in August 2018, s/n 1418) I didn't pursue obtaining the shim and knob when the switch problem first starting appearing because my meter was working fine and I figured that the thickness tolerance on my PC board must have been such that my meter was not one of those affected. But things have gradually gotten worse to the point where now the meter only powers up if I mess with the function switch a bunch of times. Maybe the springs in switch contacts have lost some oomph or something else has worn. Anyway it would be great to source the updated knob and shim now and any help from this forum would be appreciated.
If you can't read German, you could buy them from Dave:
https://eevblog.store/products/brymen-bl21s2-t4sc-gold-plated-silicone-test-probes (https://eevblog.store/products/brymen-bl21s2-t4sc-gold-plated-silicone-test-probes)
My function switch has become flaky and I need to know if the shim and replacement knob are still available and, if so, where do I get them. I was part of the original Kickstarter project and my meter was one from the 2nd production batch. (I received it in August 2018, s/n 1418) I didn't pursue obtaining the shim and knob when the switch problem first starting appearing because my meter was working fine and I figured that the thickness tolerance on my PC board must have been such that my meter was not one of those affected. But things have gradually gotten worse to the point where now the meter only powers up if I mess with the function switch a bunch of times. Maybe the springs in switch contacts have lost some oomph or something else has worn. Anyway it would be great to source the updated knob and shim now and any help from this forum would be appreciated.
I've got a few left, email me your postal address.
Only 10.90 € for a complete new set:
https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads (https://www.welectron.com/Brymen-BL21S2-T4SC-Silicone-Test-Leads)
I'm new here, but I have a 121GW with firmware 2.05. Can anyone tell me how to turn the beeper off when making low resistance measurements?The 121GW doesn't beep during low resistance measurements unless you have the continuity mode selected. "b-OFF" and "b-ON" do not apply to continuity mode.