Debugging power consumption for Sidewalk device

[raz]

I am trying to determine why our device is consistently using ~5.2 mA using the Sidewalk SDK and configured to use the LoRa PHY. I have turned off all peripherals and enabled power management. The current consumption is indicative of the Semtech radio remaining on even after switching to the SubG-CSS Profile A mode. Unfortunately I do not have a logic analyzer handy at the moment so cannot verify what is being sent to the SX1262 in that way. It is my understanding that turning the radio off is handled under the covers by the Amazon/Nordic libraries, but I do not see evidence of that actually happening. Are there some debugging features that can be enabled to see when the library has allegedly turned the radio off and on?

Thank you.

[runsiv]

Hi, 

I will look into it. From what I have read the idle current consumption should be around 3.3 µA during idle so I agree ~5.2mA seems to be to high. 

Regards

Runar

[raz]

I started to setup the nrf52840-DK with the unadulterated template_subghz project to compare current consumption through the PPK II, but upon further reading, my understanding is that the current measurement setup on the DK would only measure the consumption of the nrf52840 and nothing else. Specifically, it would not show the current draw of SX1262, LEDs, etc. etc.

Is my understanding correct?

EDIT: To be clear, the ~5.2 mA measurement was on a custom board measured through a DMM7510, not the PPK II.

[runsiv]

Ah thanks for the clarification. If you have the PPK2 in ampere meter mode and use an external dc power supply you should be able to measure the Semtech chip too. The measurements I have received from the developers with an template lora example is roughly 20µA

Did you flash the mfg.hex? I was also notified that if that the current consumption is higher during the registration/time sync so if there is no Echo nearby the current can be higher. 

I have also asked the developers regarding alternative ways to check if the radio is turned off. 

Regards

Runar

[raz]

In order to measure the Semtech chip as well should I cut SB40 or not? Does a guide exist for setting up the PPK II with the nrf52840-DK? I saw the one for the PPK II + nrf9160-DK but there seemed to be some minor differences that made me second guess some things.

Also, yes, my measurements were taken after registration was successful, time sync was successful, and link was up. That is why I'm thinking something isn't behaving properly. In profile A mode, the radio should be getting turned off after all of that.

[runsiv]

Thanks for the update, it's been a nation holloyday so sorry for the late response. 

We have a guide for the nrf52840dk here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fug_sniffer_802154%2FUG%2Fsniffer_802154%2Finstalling_sniffer_802154.html  I am awaiting the repones regarding if the SB40 was cut on the plot I posted in my last response. 

Regards

Runar