How to Record Continuously for 3 hours in PPK2 Scope/Trigger Mode?

[siatran]

Hello everyone,

I am currently working on a school project in which I need to record the energy consumption (mA) of ESP32-H2s over a 190 minute period using the Nordic Power Profiler Kit II (PPK2). The ESP32-H2s operate in deep sleep and send a packet (using OpenThread) once every 30 seconds. As a result, I would like to record their energy consumption only when they are awake and sending a packet.

I don't want to use Data Logger mode, as I measuring them at 100k samples per second, and it would result in very large files that will take a long time to parse into .csv. It will take even longer afterwards too, as I will have to use a Python script to go through the CSV to calculate the average over the whole 190 minute period.

I am using Trigger/Scope mode for the PPK2. However, I cannot seem to get the Trigger/Scope mode to measure continuously for 190 minute period. Rather than recording the energy consumption every time the device wakes up, the PPK2 under Scope mode would instead record a 1 second interval in which the device woke up, sent a packet, and go back to sleep. Then when the device wakes up again, the previous 1 second interval would be overwritten by measurements for the 1 second interval that happens the next time the device wakes up.

As a result like to ask how I can get my PPK2s to record using Trigger/Scope mode for a continuous period time of 190 minutes. Or is it not possible to do this week the PPK2? In addition, I was thinking about using the unofficial PPK2 Python API, but I believe API does not yet support Trigger/Scope mode.

Any guidance, feedback, and advice on how I can use trigger mode to record device wakes for a 190 minute period, at 100k samples per second, would greatly be appreciated.

[Simonr]

Hi

You need to increase the temp disk space allocated for the Power profiler in order to allow for higher samples to be sampled. Note that I would recommend using the data logger rather than the trigger/scope mode even though it will take some time.

Best regards,

Simon

[siatran]

Hi Simon,

I greatly appreciate you taking the time to answer my question.

I don't believe the temp disk space is a problem, as I was able to record for 190 minutes, at 100k samples per seconds, with no issues at data logger mode.

Nonetheless, the reason I don't want to use data logger mode in this case is the files are too big, to the point where it will take a significantly long time to convert them into a CSV (and even longer to use a Python script to find the average mA in the enter CSV, not to mention potential arithmetic overflow issues as well). 

In order to avoid this issue, I would like to only record the energy consumption only when the device wakes up. I programmed them to wake up in 1 second intervals every ~30 seconds. This will make it much more manageable for me process the data for my project.

This is why I would like to use Trigger/Scope mode if possible, only recording the mA when the device wakes up at a high sampling rate. 

As a result, I have the the following followup questions:

1. Is it possible to use Trigger/Scope mode in the way I intend to use it, or do I need to do data logger mode to record continuously over ~3 hour period?

2. Is it possible to use Trigger/Scope mode in a timed manner, or do I have to manually press "Stop" every time I am done?

3. Is it possible for Trigger/Scope mode to record for an interval greater than 1 second, or is 1 second the maximum? The reason I am asking is because there are time the device is wake for slightly longer than 1 second, and I would like to record every peak.

Although (2) and (3) are trivial questions (as I don't believe it is currently possible to do either on the PPK software), I would like to ask and double check.

Your advice and feedback on my questions would extremely be appreciated, as it would help me make an informed decision on whether Data Logging or Trigger/Scope mode would best fit my use case.

Thank you very much, 

[Simonr]

Okay, thank you for clarifying. I will have to check with the devs if we have a way to do this, but I'm not sure that this feature is implemented at the moment. I'll get back to you with what I find out, but it might take a few days. Since this Friday and Monday are bank holidays in Norway I'll get back to you on Tuesday May 21st if I don't hear anything by tomorrow afternoon. Thank you for your patience!

Best regards,

Simon