#include <REGX52.H>

#define F_CLK 18432000
#define F_INT 1000


typedef unsigned char byte;


byte xdata CRVENE _at_ 0x8000;
byte xdata ZELENE _at_ 0x8001;
byte xdata ZUTE _at_ 0x8002;
byte xdata PLAVE _at_ 0x8003;

byte LEDS;

unsigned long sys_time = 0;

void timer2_ISR() interrupt 5
{
 			sys_time++;
		  TF2 = EXF2 = 0;
}

unsigned long millis()
{
 			unsigned long tmp;

		 EA = 0; //zabrana prekida
 		 tmp = sys_time; //ocitavanje vremena
 		 EA = 1; //dozvola prekida

 		return tmp;
}

void delay_ms()
{

		 unsigned char SW1;

		 unsigned long t0 = millis();

		 SW1=~CRVENE & 0x03;

		 switch(SW1)
		 {
		     case 0x00:
				 while(millis() - t0 < 36);
				 break;
				 case 0x01:
				 while(millis() - t0 < 72);
				 break;
				 case 0x02:
				 while(millis() - t0 < 143);
				 break;
				 case 0x03:
				 while(millis() - t0 < 289);
				 break;
		}



}
void koja_boja(unsigned char boja)
{
	unsigned char dozvola = 1;

		if(dozvola == 1)
				{
			 	LEDS=~(~LEDS >> 1);
				 boja = LEDS;

				if(~LEDS & 0x01) dozvola = 0;
				}
				else
				{
				 LEDS=~(~LEDS << 1);
				 boja = LEDS;
				if(~LEDS & 0x80) dozvola = 1;


}


void main()
{

			unsigned char SW2;

			//inicijalizacija tajmera 2:
 			RCAP2H = (-(F_CLK / (12 * F_INT))) >> 8;
 			RCAP2L = (-(F_CLK / (12 * F_INT))) & 0xff;
 			T2CON = 0x00; //tajmer 2 -> 16-bitni auto-reload
 			ET2 = 1; //dozvola prekida tajmera 2
			 TR2 = 1; //tajmer 2 ON

			 EA = 1; //dozvola prekida







 			while(1)
			{
				delay_ms();


				   SW2=~CRVENE & 0xC0;

				 switch(SW2) {
                case 0x00:
                    if(CRVENE != prethodna_vr) {
						delay_ms();
                        CRVENE = 0x7F;
						ZUTE=0xFF;
						ZELENE=0xFF;
						PLAVE=0xFF;
						LEDS=0x7F;
                        prethodna_vr = 0x00;
                    }
					delay_ms();
					koja_boja(CRVENE);
                break;
                case 0x01:
                    if(CRVENE != prethodna_vr) {
						delay_ms();
                        CRVENE = 0xFF;
						ZUTE=0x7F;
						ZELENE=0xFF;
						PLAVE=0xFF;
						LEDS=0x7F;
                        prethodna_vr = 0x01;
                    }
					delay_ms();
					koja_boja(ZUTE);
                break;
                case 0x02:
                    if(CRVENE != prethodna_vr) {
						delay_ms();
                        CRVENE = 0xFF;
						ZUTE=0xFF;
						ZELENE=0x7F;
						PLAVE=0xFF;
						LEDS=0x7F;
                        prethodna_vr = 0x02;
                    }
					delay_ms();
					koja_boja(ZELENE);
                break;
                case 0x03:
                    if(CRVENE != prethodna_vr) {
						delay_ms();
                        CRVENE = 0xFF;
						ZUTE=0xFF;
						ZELENE=0xFF;
						PLAVE=0x7F;
						LEDS=0x7F;
                        prethodna_vr = 0x03;
                    }
						delay_ms();
						koja_boja(PLAVE);
                break;
            }

				/*if(dozvola == 1)
				{
			 	LEDS=~(~LEDS >> 1);
				 CRVENE = LEDS;

				if(~LEDS & 0x01) dozvola = 0;
				}
				else
				{
				 LEDS=~(~LEDS << 1);
				 CRVENE = LEDS;
				if(~LEDS & 0x80) dozvola = 1;*/
				}
			}
}