Control the Direction of Rotation of a Motor from Anywhere using Mobile Phone
The MT8870DE is a complete DTMF receiver which can be used to get the binary coded decimal corresponding to each switches of mobile phone key pad for external interfacing. If four LEDs are connected to the output pins Q4 (14), Q3 (13), Q2 (12) and Q1 (11) of MT8870DE, binary coded decimal corresponding to each switch will be displayed in the LEDs. If ‘1’ is pressed, output will be 0001. If ‘2’ is pressed, output will be 0010. If ‘3’ is pressed, output will be 0011. If ‘4’ is pressed, output will be 0100. Video demonstration and circuit for getting the binary coded decimal corresponding to each keys of a mobile phone is given in my previous blog.
Video demonstration of controlling the direction of rotation of a DC motor using mobile phone through an MT8870D DTMF receiver is given below. Same motor can be controlled from anywhere in the world through other mobile phones also. Do the following steps to control the direction of two DC motors from anywhere through your mobile phone.
- Take two mobile phones and connect first phone to MT8870D through an audio jack.
- Take second mobile phone and call to the phone connected to MT8870D (first mobile phone) from second mobile phone.
- When the phone connected to MT8870D (first mobile phone) rings, accept call.
- Now, call will be in progress between first and second mobile phones. Take the keypad in first mobile phone and press numbers. If ‘1’ is pressed, one motor will rotate in a direction. If ‘2’ is pressed, that motor will rotate in opposite direction. If ‘3’ is pressed, motor will stop rotation. Press ‘4’ and ‘8’ for rotating the other motor.