SampleTimerAVR.c

/*
 * main.c
 *
 *  Created on: Jan 4, 2017
 *      Author: eamanu
 */

#include <avr/io.h>
#include <avr/interrupt.h>

/**
 * To send data to USB
 */
#include "stduart.h" //lib to print/read data from USB
#include "uart.h" // lib to UART comm

volatile uint8_t count; //global variable

void configTimer ( void ); // config the Timer


int main ( void ){
	/*init uart*/
	uart_init();

	/*configure timer*/
	configTimer ( );

	/*intizialize interrupt*/
	sei ( );

	prints ( "start counter ");
	while( 1){ // infinite loop

	}
	return 0;
}


void configTimer ( void ){
	// Prescaler = FCPU/1024
   TCCR0B |=(1<<CS02)|(1<<CS00);

   //Enable Overflow Interrupt Enable
   TIMSK0|=(1<<TOIE0);

   //Initialize Counter
   TCNT0=0;

   //Initialize Counter
   count=0;
}

ISR(TIMER0_OVF_vect)
{
   //This is the interrupt service routine for TIMER0 OVERFLOW Interrupt.
   //CPU automatically call this when TIMER0 overflows.

   //Increment our variable
   count++;
   printi ( count );
   endl;
   if(count==61)
   {
      //PORTC=~PORTC; //Invert the Value of PORTC
	   prints ("count == 61. Now count is 0 ");
	   endl;
      count=0;
   }
}