I’m working on a custom PCB that includes an MCU and a BG950A-GL modem. I’m experiencing an issue where the modem stops responding after sending a specific sequence of AT commands.
Here’s the sequence I’m sending:
(waiting for "APP RDY")
ATE0
AT+CFUN=4
AT+CMEE=1
AT+QCFG="band",0,0,0x80000,1
AT+QCFG="iotopmode",1,1
The problem occurs after the last command (AT+QCFG="iotopmode",1,1) — the modem does not return OK. After that point, if I power-cycle the board, the MCU starts up normally, but the modem appears unresponsive (no “APP RDY”, no AT responses).
I’ve reproduced this on three separate PCBs, so it seems consistent and not a single-board fault.
Has anyone seen similar behavior with the BG950A-GL? Could this sequence be locking up the modem or requiring a specific recovery method? Any insight or suggestions would be greatly appreciated.
Thanks!
