AT+CMGF - Set SMS Text Mode or SMS PDU Mode
The AT+CMGF command sets the GSM modem in SMS Text Mode or SMS PDU Mode.
In Text Mode, SMS messages are represented as readable text. In PDU Mode, all SMS messages are represented as binary strings encoded in hexadecimal characters like 31020B911326880736F40000A900.
Although Text Mode is easier to use, PDU Mode is more consistent on different GSM Modems.
<mode>: 0 = PDU Mode, 1 = Text Mode
<CR> = ASCII character 13
Set the GSM modem to Text Mode SMS and send a message to GSM number +31628870634.
AT+CMGF=1 OK AT+CMGS="+31628870634" > This is the text message.→ +CMGS: 198 OK
AT+CMGS - Send SMS Command in Text Mode
AT+CMGL - List Received Messages in Text Mode