Is there a GSM mobile phone that is able to close or open an electric circuit?

Question

The question is because I need the hpone to act as a remote control to turn a light on and off

Answer 1

Hmm, if you're software savvy, you could write a program that could do this. You could either have your phone email a special email account on your computer that it can check on its own looking for a specific text string you send it and then it could perform the action via serial/parallel port, a D/A and some relays, or you could have another phone hooked up to your computer to receive the text message and have software interpret the text messages. You could probably get a basic stamp to do the same thing with a mobile phone and eliminate the computer entirely. Another idea would be to get one of those devices that sense when your cellphone is ringing. Most trigger a little light or something. You could remove the little light, put in a relay and have that trigger a circuit that would toggle your light you wish to switch on and off. A phone would just have to be placed nearby the cellphone ring sensor and then you'd just call that phone when you wanted it to switch on and off. Ah, another idea! Record a ringtone that is made up of just one specific touch tone played continuously. Set up the mobile phone that will be your control to ring that touch tone when the phone of your choice calls it; distinctive ringing for just that number (lets say its another mobile of yours). Build a touch tone decoder circuit that will trigger a relay to toggle your switch! You could change your SMS tone to another touch tone so you could send a different command. One could be on and one could be off. That way you'll always know if it is in the on or off position and not just toggle between the two.