Dual Tone Multi-Frequency Home Modulation System

February 8, 2019 · 3 minutes read

Demonstration of the working of the Prototype

Technology has advanced more and more over the years, and with this advancement, it has become an essential part of our lives. It has made our lives more comfortable and at the same time easier. We are able to access and do more work efficiently and much more easily without much human effort. Technology is substituting the manual work and everything we do in our day to day lives is becoming more automated.

The DTMF based home automation system aims at controlling a circuit or electrical network consisting of electrical appliances such as a fan, light bulb, etc. or similar circuit using frequency generated by a phone, and a DTMF decoder which decodes these frequencies. The commands are fulfilled with the help of a micro-controller that operates the circuit as desired. It is controlled from a mobile phone even at a far away distance by making a call to the other mobile phone attached to the DTMF decoder in the home automation system. During the course of the call, if any button is pressed, the tone corresponding to the button pressed is heard at the other end. This tone is called ‘Dual Tone Multi Frequency’ tone or DTMF. The aim of this project is to reduce manual labour and assist people to use technology for their comfort. It also saves the time and energy which is otherwise wasted in physically controlling home appliances. The system is not much expensive and easy to use as there is less hardware involved and you can potentially handle the appliances till the point your phones continue to communicate with each other.


Generally, appliances used in our home are controlled with the help of switches. Home automation eliminates the physical need to operate the switches and can use wireless technology to do the same. It reduces the human effort and also in turn provides a power saving alternative. It also saves time because when you have everything at your fingertips you don’t really need to go and physically switch on or switch off the appliance you want.

  • Just using your mobile phone, you can control home appliances from anywhere.
  • It reduces wastage of electricity when we forget to switch off appliances and leave the house.
  • It is very budget friendly as compared to other technologies like GSM.


This project was aimed at simplifying the switching on and off of relay circuits. The LEDs in our project can be replaced by AC devices such as fans, lights, etc. DTMF based home automation system is an efficient and simple alternative to control household devices wirelessly. It is considerably cheaper to make since it only uses one micro-controller and a receiver. The system can be accessed using another mobile device (phone) to connect wirelessly and generate a tone of dual frequencies using the numerical pad to switch on the correct relay. Thus, this is a flexible and powerful tool for wirelessly switching on relay circuits at home even from a distance.

Thus appliances that are connected to electric supply via switches, in this world of advancing technology, that can be automated, to operate wirelessly using a mobile device.

  1. Digvijay Ghotane
  2. Karan Chauhan
  3. Mohit Hassani 
  4. Rajit Bharambe