Power Profiler Kit Accuracy and change number of exported samples per time

[olibro]

I wonder about the accuracy specifications in chapter 9 of the ppk user guide. It says +-20% of readout on average value. Is this only the calculated average of the python software?

When I use the logging module to export current over time in a text file which accuracy can I expect? What do Rx_Offset and Rx_Resol mean in Table 9 of the ppk user guide?

I have read your blog poste about the comparison with a keysight power profiler.

In addition I would like to increase the output of samples of the logger module. In the beginning of ppk_plotter.py there is this line

self.avg_interval   = self.sample_interval * 10

When I decrease the multiplicator by 2 i see that the loginterval in the textfile decreases also by 2. For a beacon with 1s advertising interval I see now an advertising interval of 500ms which is wrong. Do I have to change another line in the code?

Thank you

[haakonsh]

Hey olibro,

I believe the sample rate for the average window is set in PPK FW to 7.7kHz. By changing the plotters sample interval you will get a distortion of the plotted x axis and not a change in actual sample rate. What you need to do is to log data from the Trigger window, whose sample is 77kHz. This is not a supported feature and it's therefore up to you to implement. I suggest you take look at the RTT communication, how the Trigger and Average data is transferred and processed. 

 
We are going to release a completely new application in a few weeks as a plugin to nRF Connect. It will greatly improve the user experience, but sadly it will not support the logging feature in the initial release. Logging feature is scheduled for a future release.  

Cheers,

Håkon.

[olibro]

Thank you for the answer. This helps a little. Sadly I have no time to change the code according to my needs. Will you announce the plugin on some Nordic page?