stlk

AT+CMGL - precist neprectene zpravy
AT+CMGL="REC UNREAD" - read unread SMS
AT+CMGL="ALL" - read all SMS
AT+CBC - baterka
AT+CNMI - notifikace

AT+CMGF=1 - set text mode

AT+CMGS="+85291234567"<CR>It is easy to send text messages.<Ctrl+z>

stlk

6 - RX
7 - TX
9 - test 
10 - GND
11 - +3V

I think pin 9 and 11 must be join.

const unsigned char para[3]="AT"; 
const unsigned char dial[17] ="ATD0770520112;\n\r";