Here in this project the parameters of the motor such as direction and speed will be controlled by using DTMF technology which is an inbuilt feature of PC. The project will be designed in such a way that the microcontroller will be interfaced to the PC through a DTMF decoder. And a DC motor which has to be controlled will also be interfaced to the controller through a voltage driver IC L293D. Some keys in the keyboard of PC will be dedicated for various operations which are needed. Whenever a key among those keys is pressed, the appropriate frequency will be detected by the controller by means of the DTMF decoder. Now it is the job of microcontroller to perform the predefined task of setting the motor’s speed and direction depending on the key pressed. Here an LCD will also be provided to display the status of motor i.e. the direction and the speed of the controller.
This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.