SIM not registering to HL7810 when using VBATT

Hey all,

I’ve encountered a problem while doing the low current guide from EVK Tutorial.
When I connect the modem with a DC supply - the SIM card registers just fine (AT+CEREG? 0,1). However, when I (following the manual instructions, of course) connect the Vbatt via the banana plugs - the SIM card registration fails (AT+CEREG? 0,3).
The power supply has 1 A current, while the peak current of HL7810 is 480 mA - so it should not be the problem.
Am i missing something crucial here?

Best regards,
Saulius J

Hi @saulius.juociunas,

Welcome to our community!

Based on the description, I understand that you are powering the EV Kit using through a micro-USB cable connected to the kit and the PC via UART1, and the SIM card registers just fine (AT+CEREG? 0,1), is that correct?

When you are performing Low Power Mode Current Measurements, did you follow the steps in the Hardware Setup: Board Configuration, Connect Otii to Dev Kit Board, and Turn the WAKE_UP Pin ON correctly?

In case you have followed the instructions correctly but still encounter issues with the network, please share the output for both cases: when the SIM card registers fine (AT+CEREG? 0,1) and when the SIM card registration fails (AT+CEREG? 0,3) with me.



Sorry for late reply.
I’ve already encountered the problem - I was using battery supply, and manual was missing the necessary instruction of fusing VBATT_PA with VBATT.

Problem solved, thanks all