/*
 * Blink Test Program
 *
 * Use this program to test your light-controlled LED switch -- it toggles PC0 at 2Hz.
 *
 * Last Modified 2010/09/22 21:41 (ebw)
 */

#include <avr/io.h>           // for PORTx, DDRx
#include <util/delay.h>       // for _delay_ms()

#define PORTC_LED 0           // LED is on PC0

unsigned char ledIsOn;

void init()
{
    DDRC  = _BV(PORTC_LED);   // LED on PORTC is an output
    PORTC = 0x00;             // all of PORTC starts off low (LED off)

    ledIsOn = 0;
}


int main()
{
    init();

    while (1)
    {
        if (ledIsOn)
            PORTC &= ~(_BV(PORTC_LED));  // LED -> off
        else
            PORTC |= _BV(PORTC_LED);     // LED -> on

        ledIsOn ^= 1;                    // toggle ledIsOn 

        _delay_ms(500);                  // snooze 500 msec
    }

    return 0;                  // never executed...
}