#define ANODEL PORTD.6
#define ANODER PORTD.7

#define RST PORTB.0
#define CH0 PORTB.1
#define CH1 PORTB.2
#define CH2 PORTB.3
#define CH3 PORTB.4
#define CH4 PORTB.5

register unsigned char pos=0, slot=0;
unsigned char height[2] = {10,10};
unsigned char bar = 0;
unsigned char delay=0;
#define MAX_BAR 99
interrupt [TIM0_OVF] void timer0_ovf_isr(void){
	TCNT0=180; // 70 ms between interrupts.
	
//		Allow timing signal interrupts	
#asm("sei")

	if(delay){
		delay--;
		return;
	}
 	pos++;
 	slot++;
	if(pos > MAX_BAR){
		CH0=0;
		CH1=0;
		CH2=0;
		CH3=0;
		CH4=0;
		bar=1-bar;
		if(bar){
			ANODER=1; ANODEL=0;
		}else{
			ANODEL=1; ANODER=0;
		}
		RST=1;
		pos=0; slot=0;
		delay=1;
		return;
	}
	if(pos>height[bar]){
		ANODEL=0;
		ANODER=0;

		CH0=0;
		CH1=0;
		CH2=0;
		CH3=0;
		CH4=0;
		RST=0;
		return;
	}
	if(slot>4)
		slot=0;
	switch(slot){
	case 1:
		CH0=1;
		CH1=0;
		CH2=0;
		CH3=0;
		delay_us(1);
		CH4=0;
		RST=0;
		return;
	case 2:
		CH1=1;
		CH2=0;
		CH3=0;
		CH4=0;
		RST=0;
		delay_us(1);
		CH0=0;
		return;
	case 3:
		CH2=1;
		CH0=0;
		CH3=0;
		CH4=0;
		RST=0;
		delay_us(1);
		CH1=0;
		return;
	case 4:
		CH3=1;
		CH0=0;
		CH1=0;
		CH4=0;
		RST=0;
		delay_us(1);
		CH2=0;
		return;
	case 0:
		CH4=1;
		CH0=0;
		CH1=0;
		CH2=0;
		RST=0;
		delay_us(1);
		CH3=0;
		return;
	}

}