nask0@dev-nask0 /mnt/301d7a40-8c00-4bbf-bae9-c11cc9320e48/src/git/usbserial $ sudo ./usbserial -n /dev/ttyACM0 -b 460800
**************************************************
* Serial open:         /dev/ttyACM0              *
**************************************************
Type quit, bye or ^C to exit.
AT+CMGF=1
>> AT+CMGF=1
<< OK
AT+CMGL="ALL"
>> AT+CMGL="ALL"
<< +CREG: 4
AT+CMGL="ALL"
>> AT+CMGL="ALL"
<< ERROR
AT+CMGF=1
>> AT+CMGF=1
serial_port_readline() failed: Resource temporarily unavailable
serial_output end!