#include "temp.h"

void Delay1ms(uint y) {
	uint x;
	for(; y > 0; y--) {
		for(x = 110; x > 0; x--);
	}
}

uchar Ds18b20Init(void) {
	uchar i;
	DSPORT = 0;		// Pull down bus
	i = 70;
	while(i--);
	DSPORT = 1;		// Pull up bus
	i = 0;
	while(DSPORT) {
		Delay1ms(1);
		i++;
		if(i > 5) return 0;
	}
	return 1;
}

void Ds18b20WriteByte(uchar payload) {
	uint i, j;
	for(j = 0; j < 8; j++) {
		DSPORT = 0;
		i++;
		DSPORT = payload & 0x01;
		i = 6;
		while(i--);
		DSPORT = 1;
		payload >>= 1;
	}
}

uchar Ds18b20ReadByte(void) {
	uchar byte, bi;
	uint i, j;
	for(j = 8; j > 0; j--) {
		DSPORT = 0;
		i++;
		DSPORT = 1;
		i++;
		i++;
		bi = DSPORT;
		byte = (byte >> 1) | (bi << 7);
		i = 4;
		while(i--);
	}
	return byte;
}

void Ds18b20ChangTemp(void) {
	Ds18b20Init();
	Delay1ms(1);
	Ds18b20WriteByte(0xCC);
	Ds18b20WriteByte(0x44);
}

void Ds18b20ReadTempCom() {
	Ds18b20Init();
	Delay1ms(1);
	Ds18b20WriteByte(0xCC);
	Ds18b20WriteByte(0xBE);
}

int Ds18b20ReadTemp() {
	int temp = 0;
	uchar th, tl;
	Ds18b20ChangTemp();
	Ds18b20ReadTempCom();
	temp = th;
	temp <<= 8;
	temp |= tl;
	return temp;
}