High eDRX current consumption on NRF9161_DK and disable the UICC interface during eDRX not working

[mnjLC]

Hello all,

We are taking our power measurements on NRF9161 DK board PCA10153 0.9.1. We are using NB-IoT for the LPWAN conection  We are supplying power to the board using the source meter mode on the NRFPPK2. To confirm that sim shut off is possible on our sim, we captured the AT+CRSM command output as below. 

> AT+CRSM=176,28589,0,0,0

+CRSM: 144,0,"01000803"

OK

According to this post, our sim is capable of sim shutodown. But still our sim is consuming 62uA of current during the eDRX cycles. Below is the screen shot of the sim current measurement of ~62uA.

Next, we tried taking current measurement for the e-DRX cycle. Cycle of 81.92s and PTW of 5.12s.

> AT%XDATAPRFL?

%XDATAPRFL: 0
> at+cedrxs=2,5,"0101"

OK
> at+cfun=1

OK

+CEDRXP: 5,"0101","0101","0011"
> at%xptw=5,"0001"

OK

+CEDRXP: 5,"0101","0101","0001"
> at#xsleep=2

OK

We see that the NRF9161 is consuming high current as compatred to NRF9160. Below is the screenshot of measured current consumption

Average measured current over a period of 10 minutes is 208uA seen in the image above.

With all the above information, we would like to report two bugs

1. Sim is not turning off during the e-DRX cycle

2. Floor current too high assuming sim is off during the edrx cycle. Currently with sim in ON state the floor current is 81uA
   
   

I am attaching the modem trace logs on this thread. Can someone from nordic look into this issue?

trace-2024-02-09T05-59-48.207Z.mtrace

[papatel]

Thank you, this is extremely helpful Didrik regarding SIM suspend.  We will investigate further regarding how the other implementations are behaving.  This seems like a reasonable assumption that other manufacturers are forcing shutdown and not attempting the suspend command.

My engineer confirmed that the AT+SSRDA=0,1,0 command does shutoff the sim between eDRX cycles and the current consumption drops as expected.

We did end up trying the UDP example, we get exactly the current consumption we expect with sim suspend not executing (as we know doesn't work).

So we assumed GPIO problem on DK just as you did.  We set all GPIOs to HIGH/LOW values with no effect on current consumption.

As a last ditch, we just compiled the latest SLM example from source, programmed, and boom, the mystery ~50uA of consumption is gone!

So the bug is, whatever SLM firmware is being programmed from the wizard below is introducing ~50uA more of floor current as compared to documentation and the SLM compiled from the nrfConnect SDK.

Your team should probably remedy this immediately.

Thank you!

-Patrick

[Didrik Rokhaug]

papatel said:

My engineer confirmed that the AT+SSRDA=0,1,0 command does shutoff the sim between eDRX cycles and the current consumption drops as expected.

I'm glad to hear that it worked.

papatel said:

As a last ditch, we just compiled the latest SLM example from source, programmed, and boom, the mystery ~50uA of consumption is gone!

Thanks, this is very useful information!

I looked a bit into the image in the Quick Start, and it has modem tracing enabled. This is what causes the extra current consumption.

I'll discuss with the team if we can make this clearer.

[papatel]

Awesome! Thank you for the excellent support.  I didn't mean to get too saucy on this thread, but we were in a time crunch that you helped us get out of.  So thank you again Didrik!

Just a simple note in the quick start about the increased current consumption due to modem tracing would be sufficient.  This would have saved us a few days of panic.  A better option would be to give the user the choice between modem trace enabled or disabled with a quick note explaining the difference.

In our actual production we want to order our nrf91x1 with the SLM release firmware pre-programmed for security and simplicity.  This is why we were worried why the SLM firmware provided was consuming more current than expected.