CIRCUIT TO CONTROL TWO DC MOTORS USING MOBILE PHONE THROUGH MT8870DE DTMF

Working

After completing the circuit, connect a mobile phone to the audio jack and dial numbers. If no responses are getting, change your phone. It’s better to use an old model phone for this purpose. If everything is fine, binary coded decimal corresponding to each keys will be displayed in the LEDs. Same motors can also be controlled from anywhere using a second phone. 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.