The circuit that uses microcontroller AT89C51 can control four devices from a distance of upto 30 metres wirelessly. An LCD module is used to show the device number and preset control time at the transmitter module.
This circuit lets you operate your home appliances such as lights and water pump from your office or any remote location. The system also gives you voice acknowledgement of the appliance’s status. It comprises microcontroller AT89C51, DTMF decoder MT8870, voice recording/ playback device APR9600.
This circuit uses a sensor for detecting a coin and a microcontroller that counts the coin and shows the count on 7-segment display. Once load switch is closed, a counter is initiated and power is given to the load until the counter decrements to zero.
This is a circuit for a microcontroller-based water level controller that turns the motor on/ off depending on the water level in the tank. The motor is turned off when voltage fluctuations or dry run occur.