In this project we are going to design a simple Alarm clock using ATMEGA32 timers. ATmega32A microcontroller has a 16 bit timer, and we will be using that timer to count the seconds and develop a digital clock.

An ATMega32 sound generator code is extremely simple to implement. Almost any GPIO pin can drive a piezo buzzer, and the output quality is fine for producing some beeps. The code shown here is the simplest one I remember using basic physics, and since it does not use PWM it could be implemented on almost any microcontroller.

My motivation for this project was to minimize the usage of functions such as _delay_ms(), _delay_us() and their derivatives with some exceptions, like delays to control the LCD.

Delay pauses the whole program, so if one is using delay for 10 seconds everything will pause for those 10 seconds, therefore nothing can be done in those 10 seconds.

The circuit works on two conditions - one is presence of light in its location and second is presence of human being, only when these two conditions are met, the controller turns the backup light ON.
These two conditions are tested by two sensors one is LDR and other is Motion sensor module. The LDR senses the presence of light and Motion sensor detects the presence of a human being in its range.