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Code : Tout sélectionner

int reset1wire(void)
{
	int status;	

	// configurer P0.28 en sortie
	IODIR0 |= 0x10000000;
	
	// P0.28 = 0
	IOCLR0 = 0x10000000;
	
	// tempo 480us
	delay(480);
	// configurer P0.28 en entrée
	IODIR0 &= 0xEFFFFFFF;

	// tempo 70us
	delay(70);
	// lecture
	if(!(IOPIN0 & 0x10000000))status = 1;
	else status = 0;

	IODIR0 |= 0x10000000;
	delay(410);

	return status;
}

Code : Tout sélectionner

void send1wirebit(char bit)
{
	if(bit)
	{
		// configurer P0.28 en sortie
		IODIR0 |= 0x10000000;
		// P0.28 = 1
		IOSET0 = 0x10000000;
		// attente 6us
		delay(6);
		// configurer P0.28 en entrée
		IODIR0 &= 0xEFFFFFFF;

		// attente 64us
		delay(64);
	}
	else
	{
		// configurer P0.28 en sortie
		IODIR0 |= 0x10000000;
		// P0.28 = 0
		IOCLR0 = 0x10000000;
		// attente 60us
		delay(60);
		// configurer P0.28 en entrée
		IODIR0 &= 0xEFFFFFFF;
		// attente 10us
		delay(10);
	}	
}

Code : Tout sélectionner

void send1wire(char data)
{
	char i;
	
	// boucle envoi
	for(i=0;i<8;i++)
	{
		// envoi bit
		send1wirebit(data & 0x01);
		// décalage de 1 à droite
		data >>= 1;
	}
}

Code : Tout sélectionner

char read1wirebit(void)
{
	char result = 0x00;
	// configurer P0.28 en sortie
	IODIR0 |= 0x10000000;
	// P0.28 = 0
	IOCLR0 = 0x10000000;
	// attente 6us
	delay(6);
	// configurer P0.28 en entrée
	IODIR0 &= 0xEFFFFFFF;
	// attente 9us
	delay(9);
	// lecture
	result = ((IOPIN0 & 0x10000000)>>28);
	
	// attente 55us (pour compléter le time slot)
	delay(55);
	// renvoi résultat lecture
	return result;
}

Code : Tout sélectionner

char read1wire(void)
{
	int i;
	char result = 0x00;
	for(i=0;i<8;i++)
	{
		result >>= 1;
		if(read1wirebit())result |= 0x80;
	}
	return result;
}

Code : Tout sélectionner

int readtemperature(void)
{
	char templow, temphigh, th, tl, res1, res2, countremain, countperc, crc;

	if(!reset1wire())return 0;
	else
	{
		// Skip ROM
		send1wire(0xCC);
		// Convert T
		send1wire(0x44);
		// attente conversion (750ms!)
		while(read1wire()!=0xFF); 
		// reset
		if(!reset1wire())return 0;
		else
		{
			// Skip ROM
			send1wire(0xCC);
			// Read Scratchpad
			send1wire(0xBE);
			// Read byte 1
			templow = read1wire();
			// Read byte 2
			temphigh = read1wire();
			// Read byte 3
			th = read1wire();
			// Read byte 4
			tl = read1wire();
			// Read byte 5
			res1 = read1wire();
			// Read byte 6
			res2 = read1wire();
			// Read byte 7
			countremain = read1wire();
			// Read byte 8
			countperc = read1wire();
			// Read byte 9
			crc = read1wire();
			
			// Write results
			putstr("templow = ");puthex(templow);putstr("\n");
			putstr("temphigh = ");puthex(temphigh);putstr("\n");
			putstr("th = ");puthex(th);putstr("\n");
			putstr("tl = ");puthex(tl);putstr("\n");
			putstr("res1 = ");puthex(res1);putstr("\n");
			putstr("res2 = ");puthex(res2);putstr("\n");
			putstr("countremain = ");puthex(countremain);putstr("\n");
			putstr("countperc = ");puthex(countperc);putstr("\n");
			putstr("crc = ");puthex(crc);putstr("\n");
			return 1;
		}
	}
}