Power Profiler only flatlines at 83.31 mA using nrf52840dk

[grestuccia]

Hi,

I have an issue with the first version PPK coupled with an nrf52840dk. I used to measure the current on the board through the nRF Connect desktop app on Linux and it always worked fine. Now, with the 3.7.0 new release and the new GUI, the app only shows a flatline at 83.31 mA instead of a dynamic value when measuring the power consumption in real time. I checked that all the switches were set correctly as before, but there is not anything that I change that modify this behavior. Is there something that I am missing? I am currently using Linux Mint 20.2, kernel version 5.4.0-81 and nrf Connect 3.7.0 with Power Profiler v3.1.2.

Thank you for the help.

[Håkon Alseth]

Hi,

 

How have you connected the nRF52840-DK?

Ampere-meter or source meter?

 

Does it behave like this with both configurations (remember that these require different physical hardware setup) ?

 

Kind regards,

Håkon

[grestuccia]

Hi, thanks for the fast reply.

The nrf52840dk is connected through usb to the computer. SB40 has been cut. Power source is set on VDD. The PPK is set on top of the board and everything is set to DK, as explained here: https://infocenter.nordicsemi.com/topic/ug_ppk/UG/ppk/ppk_power_supply.html Could you please tell me how to change the type of meter on the first version of the PPK and measure the different behaviors?

Gabriele

[Håkon Alseth]

Hi,

  

grestuccia said:

The nrf52840dk is connected through usb to the computer. SB40 has been cut. Power source is set on VDD. The PPK is set on top of the board and everything is set to DK, as explained here: https://infocenter.nordicsemi.com/topic/ug_ppk/UG/ppk/ppk_power_supply.html Could you please tell me how to change the type of meter on the first version of the PPK and measure the different behaviors?

 PPK v1 uses RTT (over the SWDIO/SWDCLK lines), so it's unfortunately easy to mistakenly reprogram the PPK itself with your own firmware.

Could you try to re-program the PPK?

The .hex file for PPK v1 can be found in the .zip here (nRF6707-SW):

https://www.nordicsemi.com/Products/Development-hardware/Power-Profiler-Kit/Download#infotabs

 

Kind regards,

Håkon

[grestuccia]

Thanks again for the support. Could you please tell me the procedure to re-program the PPK? Do I just have to put the PPK on top of the nrf52840dk, connect the usb to the nrf52840dk (not to the PPK), enter the nrf Connect's Programmer, load the hex and go to "Erase and Write"?

Here is the preview that the Programmer app shows to me when I do that procedure (without erasing and writing anything, but just reading):

Sorry to bother.

Gabriele

[Håkon Alseth]

Hi Gabriele,

  

grestuccia said:

Sorry to bother.

It is no bother at all! I'm glad that you use the forums instead of spending hours trying to get something working without reaching out for help.

 

grestuccia said:

Thanks again for the support. Could you please tell me the procedure to re-program the PPK? Do I just have to put the PPK on top of the nrf52840dk, connect the usb to the nrf52840dk (not to the PPK), enter the nrf Connect's Programmer, load the hex and go to "Erase and Write"?

Here is the preview that the Programmer app shows to me when I do that procedure (without erasing and writing anything, but just reading):

My apologies for not describing better. There is a communication switch, which routes the programming interface from the development kit to the PPK, named "SW3". You can see it in this block diagram:

https://infocenter.nordicsemi.com/topic/ug_ppk/UG/ppk/ppk_block_diagram.html?cp=10_9_4_0_0

 

If you look at this section, you can see this SW3 switch (use a pen or similar to change it if required):

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fug_ppk%2FUG%2Fppk%2Fppk_power_supply.html

 

Each time you program the device-under-test (DUT), this switch should be in the "external" position to avoid accidentally flashing the nRF on the PPK itself.

 

Could you try flashing the "ppk_110.hex" from the nRF6707-SW .zip file when the position is in "DK" position, then power cycle the whole DK+PPK, then see if you can sample anything other than a flat line with the software?

 

Here's another thread with a similar issue, where a colleague of mine has explained how to reprogram the PPK v1:

https://devzone.nordicsemi.com/f/nordic-q-a/43484/ppk-does-not-work/170395#170395

 

Kind regards,

Håkon

[grestuccia]

Hi,

I performed the reprogramming as you suggested but the situation remained the same. In order to see if the problem was in the nrf52840dk I flashed another firmware on it and, after re-plugging the PPK to the nrf, I was able again to use the Power Profiler app. So it seems that the strange behavior derives on what I flash on the nrf.

The problem now is that I have to measure the current usage on that specific firmware that causes the flatline to the PPK. I am sure that I am not overwriting the PPK firmware because I remove it everytime I need to flash the nrf. I am also sure that the firmware in question is at least working because I can interact with the board normally, and every interaction that I perform on it does not result in any variation of the power usage on the Power Profiler app.

Is there something that I have to check on this firmware that can cause this behavior?

Thank you very much.

Gabriele

[Håkon Alseth]

Hi Gabriele,

 

grestuccia said:

I performed the reprogramming as you suggested but the situation remained the same. In order to see if the problem was in the nrf52840dk I flashed another firmware on it and, after re-plugging the PPK to the nrf, I was able again to use the Power Profiler app. So it seems that the strange behavior derives on what I flash on the nrf.

The problem now is that I have to measure the current usage on that specific firmware that causes the flatline to the PPK. I am sure that I am not overwriting the PPK firmware because I remove it everytime I need to flash the nrf. I am also sure that the firmware in question is at least working because I can interact with the board normally, and every interaction that I perform on it does not result in any variation of the power usage on the Power Profiler app.

Is there something that I have to check on this firmware that can cause this behavior?

Thank you very much.

 I had a chat with the developer and hardware designers that made the PPK, and it this specific scenario came up (ie. stuck at x mA), and it is highly likely a weakness in one of the range-switches. Could you send me a direct message with your contact information (+ phone, dhl requirement) ? I'll arrange shipment of a PPK v2 replacement kit to you (free of charge ofcourse)

 

Kind regards,

Håkon

[grestuccia]

Hi, I have sent the information in DM now. Thank you very much for your help, you are very kind!

[Håkon Alseth]

Hi Gabriele,

 

Thank you for providing information. I have contacted our customer service, but not yet gotten confirmation about the shipping status of the replacement kit. PPK2 is quite a popular product, but we should get a new shipment in soon (if we're not currently in stock). I will keep this thread open and update you when I hear something.

 

Kind regards,

Håkon