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User Programmable Automatic Night Light

In this project we developed user programmable automatic night light using Microchip's 8bit MCU – PIC12F675. In this design user may be able to program and store the time duration of the master light. Compared with other designs this circuit use transformerless power supply, and TRIAC to control the master light.

Complete MCU software source code, operating guides and circuit diagram of this project is available to download at here.

To get more information about transformerless power supply please refer the Microchip application note AN954, and ST application note AN438 for MCU and TRIAC interfacing.


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The core component of this programmable light is ATmega8 low power CMOS microcontroller. The main reason to select this microcontroller is it’s lower cost and higher availability. Except for the above two reasons this microcontroller also bundled with a rich set of peripherals which including 23 GPIOs, 3 independent timers, Two-wire serial interface, EEPROM, etc.

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