Basic AT Commands for SIM900A GSM/GPRS Module
TO CHECK THE MODEM: AT OK TO CHANGE SMS SENDING MODE: AT+CMGF=1 OK TO SEND NEW SMS: AT+CMGS="MOBILE NO." <MESSAGE {CTRL+Z} PREFERRED SMS MESSAGE STORAGE: AT+CPMS=? +CPMS: ("SM"),("SM"),("SM") OK AT+CPMS?…