This project is used as an electronic private exchange. It has two telephones, which have the intercom facility, and they can be connected to the telephone line. All the functions are controlled by the 8-bit microcontroller AT89C2051 which has an Pro

8051 microcontroller interfcing to dtmf decoder..lcd functions files included..code in keil software-8051 microcontroller interfcing to dtmf decoder..lcd functions files included..code in keil software..

In the project the robot is controlled by a mobile phone that makes a call to the mobile 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 called 慏ual T