Storage space is hardly an issue when it uses an SD card. Even on a 2GB SD card you can store a rediculous amount of data when it is a plain csv file.
It is if the main way to get the data out is a bluetooth link - you have to open the cover to get the card out.
But when you are working in the field the Bluetooth function isn't all that useful.
When using it on your workbench it isn't an issue, I assume that recording through the PC software will add timestamps to the measurements?
Can you download data from the SD card over Bluetooth?
When using it on your workbench it isn't an issue,
It is if the BT module is on the end of a slow-ish serial port
Can you download data from the SD card over Bluetooth?
If not, that would be a total fail.
Dave/David - what is the transfer rate for log data over Bluetooth ?
If not, that would be a total fail.
Or perhaps, being a little less dramatic, a firmware update.
Or perhaps, being a little less dramatic, a firmware update.
Dave made it clear that the firmware of the meter is not Open Source and is not going to be released. Probably some copyright stuff by UEI. I don't know if even Dave has access to the source and can build a firmware himself or if he needs UEI for that. Firmware doesn't develop itself, UEI probably wants payment from Dave for each additional bit.
So unless Dave says some feature is going to be added, I would not count on it.
That is why I was
asking my questions before buying.
When using it on your workbench it isn't an issue,
It is if the BT module is on the end of a slow-ish serial port
Can you download data from the SD card over Bluetooth?
If not, that would be a total fail.
No you cannot, and this has been discussed before on the forum somewhere.
It is not a fail. Reading the data from the SD card over Bluetooth is not easy to do nor quick (it's BLE, and there are data rate limits and packet limits), we looked into this and it was very hard to do. It's much quicker and easier to simply remove the SD card.
It often takes longer to dick around with getting Bluetooth connected on your phone than it does the 20 seconds it takes to remove the SD card)
Dave/David - what is the transfer rate for log data over Bluetooth ?
About once a second as you see in the video.
Dave made it clear that the firmware of the meter is not Open Source and is not going to be released. Probably some copyright stuff by UEI. I don't know if even Dave has access to the source and can build a firmware himself or if he needs UEI for that.
I have the source code and can compile if needed (have not tried it).
Dave
On the Amp Hour you mention you wanted to make a last minute hardware change (albeit fairly minor), but was faced with the fact that 2000 boards had already been printed, and a cost that could not be absorbed. For this reason you were going to hold back, and maybe amend the board in a subsequent board spin. Are you planning to do this between the first Dec batch, and the April batch, using the delay as a chance to make the change? On the same note, what happens if/when there is a hardware change, and there are potentially different board revisions, with regards to firmware updates. Will updates need to be board revision specific?
Dave, is there any chance of a future update which includes timestamps with the logged data on the SD card?
A logging meter would be useful for me but timestamps would be a necessity.
Dave,
I have the source code and can compile if needed (have not tried it).
Very good.
Could you please also answer my question regarding the range button:
Page 26, RANGE button: the manual suggests that it is just for selecting the range of the diode test. Is this true? Doesn't it also allow to switch between manual and auto ranging in all the regular measurement functions and to manually select a specific range for e.g. dc voltage etc.?
Thanks.
When using it on your workbench it isn't an issue,
It is if the BT module is on the end of a slow-ish serial port
Can you download data from the SD card over Bluetooth?
If not, that would be a total fail.
No you cannot, and this has been discussed before on the forum somewhere.
It is not a fail. Reading the data from the SD card over Bluetooth is not easy to do nor quick (it's BLE, and there are data rate limits and packet limits), we looked into this and it was very hard to do. It's much quicker and easier to simply remove the SD card.
How accessible is it ? I thought it was behind the screwed-down fuse cover.
On the Amp Hour you mention you wanted to make a last minute hardware change (albeit fairly minor), but was faced with the fact that 2000 boards had already been printed, and a cost that could not be absorbed. For this reason you were going to hold back, and maybe amend the board in a subsequent board spin. Are you planning to do this between the first Dec batch, and the April batch, using the delay as a chance to make the change?
No, not going to happen.
On the same note, what happens if/when there is a hardware change, and there are potentially different board revisions, with regards to firmware updates. Will updates need to be board revision specific?
Maybe. Will cross that bridge if we ever come to it.
How accessible is it ? I thought it was behind the screwed-down fuse cover.
It is.
It takes less than 20 seconds to remove the holster, undo two screws (metal threaded insert), remove the battery cover and take out the SD card.
Yes, I timed it.
Hardly a chore for anyone who wants to do occasional data logging. And as I said, faster than dicking around with Bluetooth BLE and a ridiculously slow data rate.
If you are doing data logging all the time, I'd recommend buying a proper data logger with the convenient interface of your choice.
Could you please also answer my question regarding the range button:
Page 26, RANGE button: the manual suggests that it is just for selecting the range of the diode test. Is this true? Doesn't it also allow to switch between manual and auto ranging in all the regular measurement functions and to manually select a specific range for e.g. dc voltage etc.?
Yes, all the usual manual ranging on all the other functions.
When using it on your workbench it isn't an issue,
It is if the BT module is on the end of a slow-ish serial port
Can you download data from the SD card over Bluetooth?
If not, that would be a total fail.
No you cannot, and this has been discussed before on the forum somewhere.
It is not a fail. Reading the data from the SD card over Bluetooth is not easy to do nor quick (it's BLE, and there are data rate limits and packet limits), we looked into this and it was very hard to do. It's much quicker and easier to simply remove the SD card.
It often takes longer to dick around with getting Bluetooth connected on your phone than it does the 20 seconds it takes to remove the SD card)
Dave/David - what is the transfer rate for log data over Bluetooth ?
About once a second as you see in the video.
Out of interest, this doc seems to demonstrate the practical limitations of BLE.
https://rigado.zendesk.com/hc/en-us/article_attachments/211413708/Practical-BLE-Throughput.pdfIan.
>>Can you download data from the SD card over Bluetooth?
>>If not, that would be a total fail.
No you cannot, and this has been discussed before on the forum somewhere.
It is not a fail. Reading the data from the SD card over Bluetooth is not easy to do nor quick (it's BLE, and there are data rate limits and packet limits), we looked into this and it was very hard to do. It's much quicker and easier to simply remove the SD card.
It often takes longer to dick around with getting Bluetooth connected on your phone than it does the 20 seconds it takes to remove the SD card)
We did go over it some time ago but that discussion was about the prototype / preproduction meter. Obviously there were various problems with that revision of the meter which includes the logging. I may have gone back and cleaned up some of the posts to minimize the confusion. With the meter being released, I would not suggest anyone search through this old information.
How accessible is it ? I thought it was behind the screwed-down fuse cover.
It is.
It takes less than 20 seconds to remove the holster, undo two screws (metal threaded insert), remove the battery cover and take out the SD card.
Yes, I timed it.
Hardly a chore for anyone who wants to do occasional data logging. And as I said, faster than dicking around with Bluetooth BLE and a ridiculously slow data rate.
If you are doing data logging all the time, I'd recommend buying a proper data logger with the convenient interface of your choice.
You may well not be doing it all the time, but on the occasions you do need it, it's quite likely you will be doing multiple logging sessions, looking at results, doing another session etc., so having to swap the card could be a bit of a pain. Apart from safety, is there any ergonomic downside to running ith the cover off ? Are the screws self-tap or in inserts ?
I'm not familiar with the limitations of BLE - maybe instead of downloading the whole, log, some way of browsing it over BLE might be useful as you are often looking for particular events or at a particular time.
Dave
On the Amp Hour you mention you wanted to make a last minute hardware change (albeit fairly minor), but was faced with the fact that 2000 boards had already been printed, and a cost that could not be absorbed. For this reason you were going to hold back, and maybe amend the board in a subsequent board spin. Are you planning to do this between the first Dec batch, and the April batch, using the delay as a chance to make the change? On the same note, what happens if/when there is a hardware change, and there are potentially different board revisions, with regards to firmware updates. Will updates need to be board revision specific?
I've asked that a few times in various threads and I saw other's asking similar questions during the live feed. For what ever the reason, they have gone unanswered. Personally, I am not sure why it was brought up in the first place if discussing it was off limits. With as many meters being released, I'm sure there will be countless reviews of it. If there are problems with the hardware, I'm sure you will start hearing about them over the next several months.
If you need to check the logs often, why not just use the BT software on your phone or computer and see the data come in real time? The microSD card has to be accessed only when doing long unattended runs and then the removal isn't that big of a deal.
On the same note, what happens if/when there is a hardware change, and there are potentially different board revisions, with regards to firmware updates. Will updates need to be board revision specific?
If that's done right, any new rev will have a way for the FW to determine the hardware version ( maybe just an eeprom value for HW version, written at cal /test time), and adapt accordingly - having multiple FW versions for different hardware would be a nightmare to administer, and any rev is unlikely to need so many differences that run-time adaptation isn't feasible.
I'm not familiar with the limitations of BLE
Think "1980s modems". Single-digit kBits/sec.
Edit: I meant single-digit kB
ytes/sec.
maybe instead of downloading the whole, log, some way of browsing it over BLE might be useful as you are often looking for particular events or at a particular time.
Most likely you'd give up after a few minutes and just pull the damn card out.
It takes less than 20 seconds to remove the holster, undo two screws (metal threaded insert), remove the battery cover and take out the SD card.
Yes, I timed it.
Maybe a video showing this (plus a photo of what the meter looks on a bench like with the door left off for easy access).
What's the rated lifetime of an SD card connector (number of insertions)?
(and will joe make a machine to test that..)
(and will joe make a machine to test that..)
Joe is busy developing a machine to test the VA function of the meter with 121 GW