PPK: nRF Connect GUI hangs when I change voltage regulator level

[pieterc]

Hi everyone,

I am using the PPK to supply 3V to an external device and measure the current consumption.

When I start nrF Connect, connect to the PPK and change the Voltage Regulator value (from default 2.1V to 3V) the GUI hangs. The scrolling graph from right to left stops. When I click on the Power OFF button, it is reported that "PPK command failed" in the Log window.

I can measure that the output voltage did change to 3V (2.912V actually). If I select "Close Device" and reopen the device, it is reported "Corrupt data detected, please check connection to PPK".

If I close nRF Connect and reopen it and connect to the PPK then the Voltage Regulator output is 3V (2.912V actually)

Info that may help:

1. nrF Connect v3.3.0

2. SEGGER version: J-Link OB-SAM3U128-V2-NordicSemi compiled Jan 7 2019 14:07:15

3. Device s/n 000682661360 (PCA10040)

3. SW2 (DUT select) set to External

4. SW4 (Power select) set to Reg.

5. COM slide switch set to DK

Any tips / hints would be much appreciated.

Thanks in advance,

Pieter

https://piconomix.com

[Jørgen Holmefjord]

Hi,

Since you have set the COM switch to DK, I assume that you have connected the PPK on top of the DK, and use the power from the DK to supply the PPK and DUT? Please have a look at this answer.

Best regards,
Jørgen

[Jørgen Holmefjord]

The main problem with using the reg mode is that the measurements will not be correct, as mentioned in the documentation:

"Make sure that the PPK regulator voltage exactly matches the nRF5 DK voltage. Otherwise, current leakage may occur and lead to erroneous current readings."

I think that the issue you are seeing is related to the voltage of the regulator getting too low for the debug-chip on the DK to be able to communicate with the nRF on the PPK (since this will be powered with the regulator voltage). The J-Link OB debugger on the DK does not support level shifting, meaning it will only work with devices running on 3 V.

[pieterc]

Hi Jørgen,

This is not the issue that I am seeing. When the PPK / DK combo is connected, the default output voltage is 2.1V. When I touch the slider on the GUI to change the output voltage to 3V, the GUI hangs. It looks like the GUI loses communication with the DK. Communication is re-established If I close the GUI and reopen it. The output voltage is 3V and I can continue with my testing as long as I do not touch that slider.

Pieter