have you checked the modem | Microcontroller › AVR › By using GSM SIM 300M and Atmega8 , How to write coding for sending SMS to 3 Persons when any one the port pin gets high …? › have you checked the modem November 4, 2012 at 4:52 pm #8716 AJISH ALFREDParticipant have you checked the modem with hyperterminal, manually typing the code? connect your board with the hyperterminal and check whether your are getting the exactly same code displayed on the hyperterminal, when the pin become high.
