In fact, I want to use GSM to control the home using SMS
My question is how I can
-Send a single message to GSM containing multiple commands like(led1 off,led2 on,led3 on){send by phone to arduino}
- know the current situation if i send to arduino ((what is the situation now)) the arduino send back (the led1 is on,the led2 is off,the led3 is on){send by arduino to phone}