05 Experiment

Toggle the LED every second using Timer interrupt.

Source and description

http://sincgrid.in/avr-tutorials/avr-tutorial-experiment-5/

http://sincgrid.in/avr-tutorials/avr-tutorial-experiment-5/

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

#define LED PD4

ISR (TIMER1_OVF_vect)    // Timer1 ISR
{
    PORTD ^= (1 << LED);
    TCNT1 = 49916;   // for 1 sec at 16 MHz
}

int main()
{
    DDRD = (0x01 << LED);     //Configure the PORTD4 as output

    TCNT1 = 49916;   // for 1 sec at 16 MHz

    TCCR1A = 0x00;
    TCCR1B = (1<<CS10) | (1<<CS12);;  // Timer mode with 1024 prescler
    TIMSK1 = (1 << TOIE1) ;   // Enable timer1 overflow interrupt(TOIE1)
    sei();        // Enable global interrupts by setting global interrupt enable bit in SREG

    while(1)
    {

    }
}