Home Automation using DTMF

Normally, many home appliances can be controlled by switches. But, nowadays we often see the automation of home appliances using many technologies. This article presents the DTMF based home automation system using microcontroller. Dual Tone Multi Frequency (DTMF) is a signaling system for identifying the keys on a DTMF keypad. It is used for telecommunication signaling over analog telephone lines in the voice frequency band between communication devices and telephone handsets.
The project presents an approach of the designing of a home automation system using DTMF. DTMF stands for Dual Tone Multi Frequency. The system allows users to send commands from their cell phones to control various home appliances such as bulb, fan etc. Commands are sent via a cell phone’s numeric code dialing capability. The system is equipped with DTMF decoder and relay module for controlling any appliance. The program code is fed onto the micro-controller. The main advantage of the circuit is its vast range. We can track the status and control our home appliances from anywhere. In our system we have used four bulbs to represent AC loads and a12V transformer to power the circuit.