I'm just developing a small alarm/supervising system for my friends. The main idea is that the microcontroller receives data from different sensors (eg. anti-burglar ones, or even some sensors evaluating the health of an older/ill person), and automatically sends SMS notifications to the group of registered mobiles, if any dangerous situation is detected.
The whole thing will be open source & open hardware design.
Therefore I'm looking for any free (GPL'ed?) libraries for typical microcontrollers (PIC, 8051/2 etc.) which could be used to control sending SMS via different mobile phones, connected over RS232, Irda, BT and so on... Any pointers are appreciated.