This DTMF Shield is a Dual-tone multi-frequency signaling module decoder for Arduino With it's audio connector you can decode the crazy funny noises common phones make. If you are not sure what I'm talking about, imagine a home phone while pressing several of its keys. These Touch-Tones have a specific frequency or sound that this module can decode. This Shield is a Audio code system that will allow you to send commands to your Arduino via Audio signal.
Together with GMS / GPRS / GPS shield this module can communicate your Arduino with any phone land line or Cell phone in the world, within GSM signal range. Which goes as far as your cellphone.
Its quite convenient to send wireless commands over audio lines, like a phone call. Connected to our GSM/GPS shield, you could just call your robot and press any button or set of buttons to enable it.
Connect DFRobot mp3 module to this board to enable audio feedback when pressing keys, or a welcome message when the phone call is established. Enable GPS geo location mapping, and DTMF moving functions to have a GSM wireless networking remote controlled robot.
Note: For use with the GSM / GPS / GPRS shield, you will need an audio cable (FIT0113)