GPIO and USB - one or the other?

Do these hats needs to be plugged into the GPIO headers and USB or can you just pick one or the other?

i.e. could I just use stand off screws and plug in only via USB?

Also I notice the modem added /dev/ttyUSB0, /dev/ttyUSB1, /dev/ttyUSB2, /dev/ttyUSB03 - which one do I use when issuing commands?

I also notice that minicom does not echo the AT commands? The tutorials are silent on this.

AT responds with OK.

AT+CPIN? has no response - what could be the issue?

The tutorials talk about rebooting the module after updating usbnet - but again no information on how to reboot.




You can choose either or both. Yes, you can use it only via USB. Choose whichever suits your application.

For general use, you can use /dev/ttyUSB2 & /dev/ttyUSB3 ports.

For details on how to use minicom, refer to the following webpage.

To see the result code of the error, enable the verbose error reporting with AT+CMEE=2 , then try to run the AT commands you get the error.