There are a ton of tutorials and projects that shows you how to build and control wireless a robot. In this project, the user Techgenie explains you how to build a GSM controlled car through the cell phone keys.
If the infrared, Bluetooth and Wifi are the most common wireless technologies used to control the robots, the GSM method is less known in the DIY area. But even so, the GSM technology has its advantages compared with IR, Bluetooth or WiFi. The Bluetooth and infrared has a limited range where the robot is safe for control, while the WiFi technology require additional components and systems.
The GSM method to control a robot uses the phones as controllers and eliminates the ranges and obstructions that are found in the case of infrared or Bluetooth technology.
To build a GSM controller robot you need to attach a phone to the car and to make a call from another cell phone. Once between the phones is a connection, you can use the keys to send different tones to the car.
The instructions and components to build the GSM controlled robot is here.
