Author Topic: EEVBlog 121GW Multimeter Firmware Details  (Read 69871 times)

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Offline HKJ

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #225 on: December 09, 2018, 03:54:44 pm »
It doesn't say no where about the 55mA limit on the mA jack!


Page 32: mA / μA Jack: This input jack is used for the 50 mA, 500 μA and 50 μA current ranges. It is 400 mA HRC fused. An input warning alert functions for this jack

But I am missing the 5mA range in that list.
« Last Edit: December 09, 2018, 04:00:04 pm by HKJ »
 

Offline fboehle

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #226 on: December 09, 2018, 04:01:06 pm »
It is written on page 32 (File Version 04.12.2018)

"This input jack is used for the 50 mA, 500 µA and 50 μA current ranges

This input jack is used for the 10 A, 5 A and 500 mA current ranges. "

But yeah, a bit hidden...
...
I also see no one else has told me that and I have made a couple of posts about trying to feed 90mA into the mA jack so it can't be that obvious or well know or someone else would have said.
Thought you'd figure it out.  Didn't want to make you feel like an idiot :D 
Don't feel bad though, Iv'e done the same thing a few times but usually RTFM. |O

LOL... Nice one!  :)

I still haven't read the manual but someone posted saying they searched the newest revision of the manual and it doesn't mention it anywhere.
I haven't checked so I don't know if it says so or not, but i'll stick with the guy who says "it doesn't mention it anywhere", makes me feel a little less stupid!

Ha Ha!  :-+

So I went and read the latest updated manual for the 121GW today, dated 4th Dec 2018.

https://www.eevblog.com/wp-content/plugins/download-attachments/includes/download.php?id=19232

It doesn't say no where about the 55mA limit on the mA jack! It does however clearly say you should stick to alkaline and give lithium a miss.
I found it to be a good well set out manual and as someone who isn't so well experienced with these things as others here on the forum, I found it very easy to understand and get to grips with.
This meter really does have all the bells and whistles if you take the time to learn how to use it "properly" and understand all the features.

I did think "the meter" had a couple problems at first so that kind of put me off it. Turns out RTFM is very important indeed for this meter!

I stand corrected and the lithium mistake was mine but i still think the 55mA thing should be pointed out more obvious somewhere in the manual or even on the meter it's self as it is a rather neat niche function.

I will make the changes needed as set out in the manual and give it another chance as it seems one of the main the things I thought were wrong with the meter were actually my being naïve or mistake and not the meter.

I'll report back soon now I know how to operate it properly! I have a feeling I will be referring back to the manual a few times!  :)
 

Offline CDaniel

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #227 on: December 09, 2018, 04:54:34 pm »
It's unusual to have 500mA in the amps jack ( because of low burden ) , but on older multimeters is written " A 500mA " so you can see even if you didn't read the manual or you forgot .
I think they removed this on newer models , just " A " ... as in the picture from the manual .
« Last Edit: December 09, 2018, 04:56:58 pm by CDaniel »
 

Offline HKJ

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #228 on: December 09, 2018, 05:05:38 pm »
Now it is pointed out though I see it is a 50mA limit and not a "55mA limit" as someone else stated to start this whole thing.

The actual limit is 55mA, but in many multimeter specifications values are rounded down.
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #229 on: December 10, 2018, 01:13:46 pm »
A question about logging:
Is it possible to log both frequency and voltage simultaneously in ac mode and automatic logging?
 

Offline bicycleguy

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #230 on: December 10, 2018, 05:25:50 pm »
A question about logging:
Is it possible to log both frequency and voltage simultaneously in ac mode and automatic logging?

yes

Code: [Select]
START 2018/12/10 10 21 24
ID 170800121
INTERVAL 10 sec
MAIN SUB-1 SUB-2 Remark
No. Func. Value Unit Func. Value Unit Func. Value Unit
1 ACV 0.0046 V FREQ. 0 Hz
2 ACV 0.0114 V FREQ. 0 Hz
3 ACV 0.0122 V FREQ. 0 Hz
4 ACV 0.027 V FREQ. 0 Hz
5 ACV 0.0413 V FREQ. 0 Hz
6 ACV 0.2659 V FREQ. 59.996 Hz
7 ACV 0.2724 V FREQ. 59.999 Hz
8 ACV 0.0245 V FREQ. 0 Hz
MAX 7 ACV 0.2724 V
MIN 1 ACV 0.0046 V
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #231 on: December 12, 2018, 10:15:22 am »
A question about logging:
Is it possible to log both frequency and voltage simultaneously in ac mode and automatic logging?

yes

Code: [Select]
START 2018/12/10 10 21 24
ID 170800121
INTERVAL 10 sec
MAIN SUB-1 SUB-2 Remark
No. Func. Value Unit Func. Value Unit Func. Value Unit
1 ACV 0.0046 V FREQ. 0 Hz
2 ACV 0.0114 V FREQ. 0 Hz
3 ACV 0.0122 V FREQ. 0 Hz
4 ACV 0.027 V FREQ. 0 Hz
5 ACV 0.0413 V FREQ. 0 Hz
6 ACV 0.2659 V FREQ. 59.996 Hz
7 ACV 0.2724 V FREQ. 59.999 Hz
8 ACV 0.0245 V FREQ. 0 Hz
MAX 7 ACV 0.2724 V
MIN 1 ACV 0.0046 V

Could you then make the app plot voltage against frequency?
 

Offline EEVblog

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #232 on: December 15, 2018, 12:47:05 pm »
Can you please take this overload talk elsewhere, this thread is for firmware stuff only. Thanks.
 
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Offline joeqsmith

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #233 on: December 15, 2018, 03:10:27 pm »
No problem.  I will clean up my mess.

About two pages cleaned up for you.   If others word do the same we could get it down even lower.
« Last Edit: December 15, 2018, 03:20:09 pm by joeqsmith »
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline jancumps

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #234 on: January 09, 2019, 01:12:15 am »
With the v1.58 beta, I can't get the min/max/avg to work.
Pressing the button changes the AUTO label on the display, but min/max/avg don't cycle anymore for me.
PEBKAC
« Last Edit: January 09, 2019, 01:43:44 am by jancumps »
 

Offline alex-sh

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #235 on: January 29, 2019, 03:53:43 pm »
Anyone extensively tested 1.58 beta please? Any drawbacks?
 

Offline bicycleguy

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #236 on: January 29, 2019, 05:35:06 pm »
Best yet, no regression AFAIK
 

Offline Alex Rodriguez

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #237 on: February 25, 2019, 12:30:09 am »
The burden voltage I think  is a little off.  Using a 25Ω/5W  resistor in series with  12V DC, the 121GW shows 18.3mV burden voltage. The FLuke 28II connected in parallel to the voltage input of the 121GW shows 21.96mV.  I followed page 41 burden voltage measurement  instructions.     Of course,  there is no mention to use another DMM to confirm results.  The 121GW current measurement is right on the spot. Firmware 1_58 beta
« Last Edit: February 25, 2019, 12:33:00 am by Alex Rodriguez »
 
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Offline Candid

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #238 on: February 25, 2019, 07:44:58 pm »
 

Offline Alex Rodriguez

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #239 on: February 25, 2019, 11:30:12 pm »
You may have a look on this concerning burden voltage:
https://www.eevblog.com/forum/testgear/eevblog-121gw-discussion-thread/msg2213955/#msg2213955

My friend, yes I watched your video, but  I hate to tell you that you might have to re-do your video. Have you looked very carefully page 41 (121GW User Manual - Last Revised: 08 February 2019)?  You are using mVA/VA, and that is for something else. To measure burden voltage, you must use  mA or A.
By the way, the mVA/VA is working just fine.

Page 41 says:

To measure the burden voltage an additional lead is required, this must be
connected between the active current terminal and the voltage input, as shown below:

« Last Edit: February 26, 2019, 12:47:40 am by Alex Rodriguez »
 

Offline Uksa007

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #240 on: March 06, 2019, 06:28:49 am »
Anyone extensively tested 1.58 beta please? Any drawbacks?

Can't find any change-log details in the manual about what 1.58 beta fixes, in fact the manuals last entry is v1.51.

Did the app get updated to support the latest versions?

Whats the best stable version that works with ios app, V1.57?



« Last Edit: March 06, 2019, 06:30:21 am by Uksa007 »
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #241 on: March 12, 2019, 11:51:05 am »
Is the firmware source code available?
Are the comments inside good?

What development environment is best?
 

Online Brumby

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #242 on: March 12, 2019, 01:44:40 pm »
Is the firmware source code available?
No, and it will likely never be.  It contains proprietary content from UEI - and they are somewhat coy about sharing it.

Quote
Are the comments inside good?

What development environment is best?
No idea.
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #243 on: March 13, 2019, 04:18:45 pm »
Is the firmware source code available?
No, and it will likely never be.  It contains proprietary content from UEI - and they are somewhat coy about sharing it.

Quote
Are the comments inside good?

What development environment is best?
No idea.

So it isn't hackable, then?
 

Offline dcac

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #244 on: March 13, 2019, 05:14:53 pm »
Yeah - the 121GW is hackable - just not by compiling a new FW from official FW source code.

Though it's "simple" to do some "simple" changes by hexediting the FW bin files. Or you can do patching on assembly level using the IDA disassembler. But of course making any substantial changes this way will eventually drive you nuts.

 

Offline GeoffreyF

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #245 on: March 13, 2019, 10:24:24 pm »
When did "Hackable" imply complete information on what is to be hacked? 

Don't confuse user programmable (it isn't) with hackable (which most things actually are, this one more than others).
US Amateur Extra W1GCF.
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #246 on: March 14, 2019, 02:19:07 am »
When did "Hackable" imply complete information on what is to be hacked? 

Don't confuse user programmable (it isn't) with hackable (which most things actually are, this one more than others).
Point taken, of course.

What I'm looking to do is actually to be able to automate measurements.
I e be able to read data from the unit and possibly "press some buttons" from say a python program.
Maybe something like this can be done via bluetooth?
 

Offline GeoffreyF

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #247 on: March 14, 2019, 02:11:03 pm »
You certainly can get a stream of data through bluetooth.   The protocols for that are documented.

pushing buttons - probably not so easy. You do have open schematics and so you could solder small wires to the button contacts or something like that.   It seems to need reminding to some, for what it does the 121GW is not that expensive so - by all means hack the hardware.  It won't be CAT anything if you do but it can be modified and then put into some kind of a case that supports the connections etc.  That sounds like fun.
US Amateur Extra W1GCF.
 

Offline n3mmr

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #248 on: March 14, 2019, 05:05:25 pm »
Stream of data is what is needed for using in automated setups, so if I look at that doc on BLE, and the app's source on git, supposedly I only need a way to talk to bluetooth  from python.

"Pushing buttons" was just that the fw in tx3 lets you do just that over a serial connection

I wouldn't dream of "hacking the hardware". I want it to work reliably.
 

Offline GeoffreyF

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Re: EEVBlog 121GW Multimeter Firmware Details
« Reply #249 on: March 16, 2019, 12:36:52 am »
Hacking (or modifying) the software can interfere with reliability as well.  I think the real point here is that you need to acquire something other than a hand held DVM. 
US Amateur Extra W1GCF.
 
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