Title	DTMF Based Control System
Authors	Ahamed Faisal, Md Minul Alam, Koumudi Hossain Misha
Semester	Fall, 2015

In many cases it is desirable to turn on or off some electronics appliances, such as domestic ac, fan, light, industrial machines from a long distance or anywhere, anytime. This project will hopefully fulfill that desire. This project uses the Dual-Tone Multi Frequency (DTMF) technique to control multi electronic devices via mobile phone. The automation features of this work makes it possible for domestic and industrial owners to remotely control a large number of appliances.

With this device, 96% times we are able to control all our 12 devices at a time. Only 4% times there has been a problem that when we switch from LED to relay section to control 1 CFL bulb and 1 plug in  switch,  the  device  also  turns  on  another  LEDs. It occurs sometimes. And there was blinking in LEDs when we switch both the devices. We found that the problem occurs when we use a high power AC load. This problem is happening because of our connection or imperfect shouldering of the connection in the board. Also, it can be happen that we are dealing with AC current and with AC current devices it gives an over shot at the beginning.

Though our project isn’t 100% successful it is worth mentioning how fascinating it is to see a designed project working satisfactorily.