AT+CMGS returns ERROR

Question

I am using SIM900 GSM module connect to my AVR Microcontroller. I tested it with FT232 to see transmitting data. First Micro sends AT it will response OK

AT          


        

Answer 1

If AT+CSCS? command returns UCS2, then many arguments need to be encoded as hex string of UTF-16 encoding, so the phone number would become "002B0039003800390033...", and the SMS text would need to be encoded in the same way. If you don't need UCS2 encoding, then the easiest thing to do is to switch to GSM encoding (or another encoding from the available set as shown by AT+CSCS=? command)