Many times we wonder if all the devices can be automatically switched on or off at a particular time. In this kit time based device control we made it possible. In this kit we are using a RTC to control devices and their switch ON itself at a definite time and switch OFF at definite time.
The RTC provide us the time which is converted into digital signal using an IC and fed it into microcontroller. At the defined time, the microcontroller switches ON the device and switches it OFF after some time. The device here is multiple pump motor. In this kit we can program up to 4 devices, i.e. we can set their switch on /off time.
The circuit is based on AVR ATMEGA168 micro controller and PCF8583 real-time clock chip. An LCD module allows for user interface. The LCD module (16-character×2-line) is interfaced with the microcontroller. Real-time clock IC the PCF8583 is a clock and calendar chip, based on a 2048 bit static CMOS RAM organized as 256 words by 8 bits. Devices (pump motor) are connected to contacts of the relay and relays are controlled through the outputs of IC (ULN2803).