#include <stdlib.h>
#include <stdio.h>
#include <p89lpc9351.h>


#define B1 P1_3
#define B2 P1_4
#define B3 P1_6
#define MAX_UPPER_LIMIT 90
#define MIN_LOWER_LIMIT -90
#define UPPER_LIMIT 1
#define LOWER_LIMIT 0

#define HEX0 0x0C0
#define HEX1 0x0F9
#define HEX2 0x0A4
#define HEX3 0x0B0
#define HEX4 0x099
#define HEX5 0x092
#define HEX6 0x082
#define HEX7 0x0F8
#define HEX8 0x080
#define HEX9 0x090
#define OFF 0x080

int limit [2];

void initMC()
{
	P0M1 = 0;
	P0M2 = 0;
	P1M1 = 0;
	P1M2 = 0;
	P2M1 = 0;
	P2M2 = 0;
	P3M1 = 0;
	P3M2 = 0;
	B1 = 1;
	B2 = 1;
	B3 = 1;
}

void display(int num)
{
	int hexVal[] = {HEX0, HEX1, HEX2, HEX3, HEX4,
				HEX5, HEX6, HEX7, HEX8, HEX9};
	int digit = 0;
	if(num < 0)
	{
		P1_7 = 1;
		num *= -1;
	}
	else
		P1_7 = 0;
	digit = hexVal[num % 10];
	digit ^= 0xFF;
	P0 = digit;
	num /= 10;
	digit = hexVal[num];
	digit ^= 0xFF;
	P2 = digit;
}

void mydelay(int ms)
{
	int i;
	int j;
	for (j=0; j<ms; j++)
	{
		for (i=0; i<1840; i++)
		{
		// do nothing
		}
	}
}



void changeLimit (int i, int limit[])
{
	while (1)
	{
		P0 = OFF;
		P2 = OFF;
		P1_7 = 0;
		mydelay(30);
		display(limit[i]);
		mydelay(50);

		if (B2 == 0){
			if(!((i == LOWER_LIMIT && (limit[i] + 1 == limit[UPPER_LIMIT]) ) || limit[i] == MAX_UPPER_LIMIT ))
				limit [i]++;
		}

		if (B3 == 0){
			if(!((i == UPPER_LIMIT && (limit[i] - 1 == limit[LOWER_LIMIT]) ) || limit[i] == MIN_LOWER_LIMIT ))
				limit [i]--;
		}

		if (B1 == 1)
		{
		while (B1 == 1);
		break;
		}
	}
}

void ext_int(void)
{

	int i = 0;

	while (1)
	{

		display(limit[i]);

		if (B1 == 1)
		{
			while (B1 == 1);
			changeLimit(i,limit);
		}

		if (B2 == 0)
		{
			while(B2 == 0); // do nothing
			i ^= 1;
		}

		if (B3 == 0)
		{
			while(B3 == 0);
			break;
		}
	}
}

int main (void)
{
	initMC();
    limit[LOWER_LIMIT] = MIN_LOWER_LIMIT;
    limit[UPPER_LIMIT] = MAX_UPPER_LIMIT;
	while(1)
	{
	display(10);
	if (P1_3 ==  1){
		mydelay(250);
		ext_int();
	}
	}

}