Broken PPK?

[Arepa]

Hi Nordic team,

I was using my PPK with a custom board I used in the past testing new features in software, the PPK with nRF Connect was measuring everything fine, since yesterday when running the Power Profiler with nRF Connect, it asked for update the firmware, which I did. but since the PPK show 80mA for every consumption from my custom boards, which were before update the firmware below 12-16mA at peaks.

I don't know which firmware version was using before, and I am pretty sure my custom boards does not use more than 80mA, in the worst-case scenario 16mA.

What can I do to fix it?. beside "rollback" to the previous firmware version which version number is unknown for me.

Regards,

Arepa

[haakonsh]

What PPK board revision do you have? 

[Arepa]

it's a Rev 1.1.0

2017.17

[haakonsh]

So I've got a few things that I need you to try:

1.  In the PPK application, press ctrl+alt+a and reset the calibration values.
   
   
2. Erase and reflash the PPK.
   
   
3. If those two methods do not work, use resistor loads of 1k, 10k, 100k, and report what current consumption you measure. 

[Arepa]

Hi haakonsh 

I followed the steps above resetting the calibration values:

Reflashing the PPK, after that, I measure the load using an "external DUT" the resistors 2.2k (no 1k available for me), 10k and 100k

Here my results

100k at 3600mV - > 22.721uA

10k at 3600mv ->232 uA

2.2k at 3600mV -> 80mA

Also, I modified the Resistor calibration for high from 1.831 to 90 using the 2.2k resistor returning the exact current value using Ohm's Law for voltage and the load resistor, but is it a reliable fix to my PPK?

I am also wondering if Resistor Calibration values are actual values for the resistors High, Mid and Low position (R2, R3, R4)?

I also looked at 

https://devzone.nordicsemi.com/f/nordic-q-a/47560/power-profiler-kit-gives-wrong-current-measurments where it is a similar behavior

so the tiny R4 resistor also has a small spot, like it is burned I am going to give a try to replace it and update my response late

[haakonsh]

Those three resistor measurements are way off. 

That R4 resistor looks like it's blown, Do you know the correct value for it? 

[haakonsh]

nRF6707 Power Profiler Kit - Hardware files 1_0_0.zip

[Arepa]

Hi haakonsh I finally replaced the small resistor R4 1.8Ohm, and now the PPK is working as before measuring the current properly 

For reference, the correct combination key to access to calibration on nRF Connect - PPK 

Alt+Shift+Ctrl+a

Regards,

Arepa