mega32_light_traffic.c

#include <util/delay.h>

void SevenSegment(unit8_t count) {
    switch (count) {
         case 0: PORT_7_SEGMENT=0b10001000; break;
         case 1: PORT_7_SEGMENT=0b10111110; break;
         case 2: PORT_7_SEGMENT=0b00011001; break;
         case 3: PORT_7_SEGMENT=0b00011100; break;
         case 4: PORT_7_SEGMENT=0b00101110; break;
         case 5: PORT_7_SEGMENT=0b01001100; break;
         case 6: PORT_7_SEGMENT=0b01001000; break;
         case 7: PORT_7_SEGMENT=0b10111100; break;
         case 8: PORT_7_SEGMENT=0b00001000; break;
         case 9: PORT_7_SEGMENT=0b00001100; break;
    }
}

void counter(unit8_t from) {
    for (int c = from - 1 ; c >= 0 ; c--) {
        SevenSegment(c);
        delay_ms(1000);
    }
}

int main()
{
  // set ports as output
  DDRA = 0xFF;
  DDRB = 0xFF;

  // set all LEDs off
  PORTA = 0x00;
  PORTB = 0x00;

  // turn all segments off
  PORT_7_SEGMENT=0xFF;   

  while (1)  // main loop
  {
        // switch red light on  (clear PORTA, set PORTB)
        PORTA = 0xFF;
        PORTB = 0x00;

        // delay 10 sec and update counter
        counter(10);

        // switch green light on  (set PORTA, clear PORTB)
        PORTA = 0x00;
        PORTB = 0xFF;

        // delay 5 sec;
        counter(5);
      } // if
   } //while(1)
} //main