In this project robot is controlled by cell-phone that makes a call to the cell-phone attached to the robot. In the course of a call if any button is pressed a tone corresponding to the button pressed is heard at the other end of the call the tone is called dual-tone multiple/frequency (DTMF TONE) the robot perceives this DTMF tone with the help of the phone stacked in the robot.

The received tone is processed by the ATmega16 microcontroller with the helpof DTMF decoder MT8870.The decoder decodes the DTMF tone into its equivalent binary digit and this binary number is send to the microcontroller. The microcontroller is preprogrammed to take a decision for any given input and out-puts its decision to motor drives in order to drive the motor for forward or backward motion or a turn. 

The mobile that makes a call to the mobile phone stacked in the robot acts as a remote. So the simple robotic project does not require the construction of receiver and transmitter unit.