i need to get a c code for interfacing the microcontroller to a GSM Modem only to send sms, i have read all the AT COMMANDS of the sms and the data sheet shows me how to use the modem through the hyper terminal of the windows but it doesn't show how to interface with a micro ? can any one describe what are the steps of this ? and i need the hardware interfacing scheme to do this ? if any one have a usefull link please co-operate . thank you