samplePWMGeneration.c

/*
 * main.c
 *
 *  Created on: Jan 22, 2017
 *      Author: eamanu
 */

#include <avr/io.h>
#include <util/delay.h>

void InitPWM()
{

   TCCR0A |=(1<<WGM00)|(1<<WGM01)|(1<<COM0A1);

   /*set de CS0*/
   TCCR0B |= (1<<CS00);

   //Set OC0 PIN as output. It is pin 13 of Atmega2560
   DDRB |= (1<<PB7);
}

/******************************************************************
Sets the duty cycle of output.

Arguments
---------
duty: Between 0 - 255

0= 0%

255= 100%

The Function sets the duty cycle of pwm output generated on OC0 PIN
The average voltage on this output pin will be

         duty
 Vout=  ------ x 5v
         255

*********************************************************************/

void SetPWMOutput(uint8_t duty)
{
   OCR0A=duty;
}

/*Put a waiting*/
void Wait()
{
 _delay_loop_2(3200);
}

int main()
{
   uint8_t brightness=0;

   //Initialize PWM Channel 0
   InitPWM();

   //Do this forever

   while(1)
   {
      //Now Loop with increasing brightness

      for(brightness=0;brightness<255;brightness++)
      {
         //Now Set The Brighness using PWM

         SetPWMOutput(brightness);

         //Now Wait For Some Time
         Wait();
      }

      //Now Loop with decreasing brightness

      for(brightness=255;brightness>0;brightness--)
      {
         //Now Set The Brighness using PWM

         SetPWMOutput(brightness);

         //Now Wait For Some Time
         Wait();
      }
   }

   return 0;
}