Abstract: The project aims in designing a system which is used for controlling the AC lamp intensity operation through Mobile phone using DTMF technology. This also aims at providing a wireless and continuous control over many household as well as industrial devices. The process of home automation works by making everything in the house automatically controlled using DTMF technology. In this project we can control any electrical lamp through mobile from any distance of the world. In this project one base unit is connected to the mobile phone. When we want to control lamp through outer phone then first we dial the receiver mobile number, bell is ringing and after few bell ringing phone is automatic going to self answering mode and switch on the base unit to operate. The controller device of the whole system is a Microcontroller 89C51. DTMF decoder decodes the signal and output fed to the controller unit to which has AC lamp is connected. When the users need control the lamp intensity user call the mobile phone which is present at receiver side in the self answering mode when the call is received, as the need of user press the keys of mobile phone assigned to intensity control the lamp operation of lamp.
Keywords: DTMF 8870, Microcontroller 89C51, TCA 785, SCR.