Subversion Repositories svnkaklik

Rev

Rev 409 | Go to most recent revision | Blame | Last modification | View Log | Download

/*********************************************
* vim: set sw=8 ts=8 si :
* Author: Guido Socher, Copyright: GPL 
* This program is to test the led connected to
* PC5. 
* See http://linuxfocus.org/English/November2004/
* for details.
* Chip type           : ATMEGA8
* Clock frequency     : Internal clock 1 Mhz (factory default)
*********************************************/
#include <avr/io.h>
#include <inttypes.h>
#define F_CPU 17000000UL  // 1 MHz
#include <avr/delay.h>


/* compatibilty macros for old style */
#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif

#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif


void delay_ms(unsigned int ms)
/* delay for a minimum of <ms> */
{
        // we use a calibrated macro. This is more
        // accurate and not so much compiler dependent
        // as self made code.
        while(ms){
                _delay_ms(0.96);
                ms--;
        }
}


/* new style */
int main(void)
{
          /* INITIALIZE */
          /* enable PC5 as output */
          DDRC|= (1<<DDC5);

          /* PC5 is 5 (see file include/avr/iom8.h) and 1<<PC5 is 00100000 
           * This can also be written as _BV(PC5)*/
          while (1) {
                      /* led on, pin=0 */
                      PORTC &= ~(1<<PC5);
                      delay_ms(500);
                      /* set output to 5V, LED off */
                      PORTC|= (1<<PC5);
                      delay_ms(500);
          }
          return(0);
}


// // old style now depricated:
// int main(void)
// {
//      // enable  PC5 as output 
//      sbi(DDRC,PC5);
//      while (1) {
//              // led on, pin=0 
//              cbi(PORTC,PC5);
//              delay_ms(500);
//              // set output to 5V, LED off 
//              sbi(PORTC,PC5);
//              delay_ms(500);
//      }
//      return(0);
// }
// // end of old style