PPK2 file format

[Golaz]

I have 7 GB large .ppk2 file exported by Power Profiler v4.2.1.
I am looking for a glitch in power consumption. Doing this manually by scrolling through the waveform in Power Profiler is a no-go.

What is the exported .ppk2 file format?
I want to open and parse this file in Python.

Thanks

[runsiv]

Hi

If you in the Power Profiler app select load, you can import the .ppk2 file and then select save/export and export it to CSV

Just as a note, you might not see the load button if you connect to the PPK2 in the app

Regards

Runar

[Golaz]

I dont want to export it as CSV because it ends up being over 45 GB large.

[runsiv]

I see. I asked internally. 
Just out of curiosity what was the sampling rate and duration of this file?

Regarding the file format

The code is all open source and info on the data stored can be found here:  

https://github.com/NordicSemiconductor/pc-nrfconnect-ppk 

 

the ppk2 file is a zip file that has 3 files:

• session.raw 
• minimap.raw
• metadata.json

Manditoary Data:

• session.raw : https://github.com/NordicSemiconductor/pc-nrfconnect-ppk/blob/58324eedd07ce0e6691dbf2eb06cac81b550e302/src/globals.ts#L53
  • 4 byes for current -> decimal in uA 
  • 2 bytes for the digital channels -> 2 bits per channel LSB is Digital channel 1 (D8-D7-D6-D5-D4-D3-D2-D1)
    • Converting the 8bit digital input to the 16bit format we use:
    • https://github.com/NordicSemiconductor/pc-nrfconnect-ppk/blob/58324eedd07ce0e6691dbf2eb06cac81b550e302/src/utils/bitConversion.ts#L21
• Minimap condensed data https://github.com/NordicSemiconductor/pc-nrfconnect-ppk/blob/58324eedd07ce0e6691dbf2eb06cac81b550e302/src/utils/foldingBuffer.ts#L118 
• Metadata https://github.com/NordicSemiconductor/pc-nrfconnect-ppk/blob/58324eedd07ce0e6691dbf2eb06cac81b550e302/src/utils/saveFileHandler.ts#L32 (samples per second must be the same as supported by our app

IMPORTANT: No negative values are supported! any values  < 0.2uA is interpreted as 0

 

Converting the 3 files into ppk2

• https://github.com/NordicSemiconductor/pc-nrfconnect-ppk/blob/58324eedd07ce0e6691dbf2eb06cac81b550e302/src/utils/saveFileHandler.ts#L40 (Final Compression)

This is the best we can do I think, this is how to use the file format we use for the ppk2

Regards

Runar

[Golaz]

The data was sampled over 4 days at 10 kSa/s.

Thank you very much!