Mercurial > hg-public > freeslot / file revision

#include <avr/interrupt.h>
#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/eeprom.h>
#include <stdlib.h>
#include <stdint.h>
#include <avr/pgmspace.h>

#include "main.h"

#include "driver/rs232.h"
#include "util/delay.h"


ISR ( USART_RXC_vect ) {
}

// PD2 / PD3 = INT0 / INT1
// connect IR receiver to these pins to measure frequencies


uint8_t get_car(uint8_t pin) {
    uint8_t i=0xff;
    // wait ~~ Xµs for low signal
    while ( (PIN(PORTD) & pin) != 0) {
        _delay_us(5);
        i--;
        if (i==0) return 0; // no low signal, do not longer block
    }
    // wait until signal is high again to start measurement
    while ( (PIN(PORTD) & pin) == 0) ;
    i = 0;
    while (i<100) {
        _delay_us(4);
        i++;
        if ( (PIN(PORTD) & pin) == 0) { // return car ID
            if ( (i>= 5) & (i<= 9) ) return 1; // 05-09 = car1
            if ( (i>=13) & (i<=16) ) return 2; // 13-16 = car2
            if ( (i>=19) & (i<=22) ) return 3; // 19-22 = car3
            if ( (i>=28) & (i<=31) ) return 4; // 28-31 = car4
            // debug: return higher values:
            if (i>32) return i;
        }
    }
    return 0; // timeout or incorrect measurement
}


int main(void)
{
    uint16_t i;
    unsigned char s[30];

    RS232_init(); // initialize RS232 interface
    RS232_puts_p(PSTR("Car ID Scanner v0.1\n"));

    while (1) {
        // main loop

        i = get_car(_BV(PD2));
        if (i > 0) {
            itoa ( i , s, 10);
            RS232_puts(s);
            RS232_putc('\n');
        }

    } // main loop end
};