Hi there, I have both RM520N-GLAA and RM500U-CN. RM500U-CN works perfectly in all of my devices ( M.2 key B to USB3 board, BPI-R3 mini, BPI-R4) but RM520N-GL only works in BPI-R4. RM520N-GL can be detected normally in all these 3 devices under openwrt or other linux distributions with command ‘lsusb’. The problem is that SIM card detection only works with BPI-R4. When using the module with the other two devices, AT+CPIN? always return CME ERROR 10. The only difference between the M.2 key B on BPI-R3 mini and that interface on BPI-R4 is BPI-R4’s M.2 key B supports both PCIE/USB mode. But the module is running under USB mode for sure or it should not be detected by lsusb. Could you please point out what is the possible explanation?
Dear @gesong2077
What is the current firmware of RM520NGLAA?
Do you check the interface by AT command?
AT+QCFG=“data_interface”
I haven’t checked the firmware of the module but I did check the interface with AT+QCFG=“data_interface”. I will get back to you with the actual firmware version and might need your help to upgrade the firmware