finalDS18S20 - DS18S20

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DS18S20

DS18S20.h@0:5b6520e71eb6, 2012-04-26 (annotated)

Committer:: aitouares
Date:: Thu Apr 26 14:18:31 2012 +0000
Revision:: 0:5b6520e71eb6

Who changed what in which revision?

User	Revision	Line number	New contents of line
aitouares	0:5b6520e71eb6	1	/* D'apres : *******************************************************
aitouares	0:5b6520e71eb6	2	*
aitouares	0:5b6520e71eb6	3	* FILENAME: ds1820.h
aitouares	0:5b6520e71eb6	4	* DATE: 25.02.2005
aitouares	0:5b6520e71eb6	5	* AUTHOR: Christian Stadler
aitouares	0:5b6520e71eb6	6	*
aitouares	0:5b6520e71eb6	7	* DESCRIPTION: Driver for DS1820 1-Wire Temperature sensor (Dallas)
aitouares	0:5b6520e71eb6	8	*
aitouares	0:5b6520e71eb6	9	******************************************************************************/
aitouares	0:5b6520e71eb6	10	#include "mbed.h"
aitouares	0:5b6520e71eb6	11	DigitalInOut DQ (p15); // broche DQ relie a la broche p15 du MBED
aitouares	0:5b6520e71eb6	12	DigitalOut G__MOS_P (p16);
aitouares	0:5b6520e71eb6	13	Serial pc(USBTX, USBRX); // tx, rx
aitouares	0:5b6520e71eb6	14	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	15	/* DS1820 Timing Parameters */
aitouares	0:5b6520e71eb6	16	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	17	#define DS1820_RST_PULSE 480 /* master reset pulse time in [us] */
aitouares	0:5b6520e71eb6	18	#define DS1820_MSTR_BITSTART 2 /* delay time for bit start by master */
aitouares	0:5b6520e71eb6	19	#define DS1820_PRESENCE_WAIT 40 /* delay after master reset pulse in [us] */
aitouares	0:5b6520e71eb6	20	#define DS1820_PRESENCE_FIN 480 /* dealy after reading of presence pulse [us] */
aitouares	0:5b6520e71eb6	21	#define DS1820_BITREAD_DLY 5 /* bit read delay */
aitouares	0:5b6520e71eb6	22	#define DS1820_BITWRITE_DLY 100 /* bit write delay */
aitouares	0:5b6520e71eb6	23
aitouares	0:5b6520e71eb6	24
aitouares	0:5b6520e71eb6	25	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	26	/* DS1820 Registers */
aitouares	0:5b6520e71eb6	27	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	28
aitouares	0:5b6520e71eb6	29	#define DS1820_REG_TEMPLSB 0
aitouares	0:5b6520e71eb6	30	#define DS1820_REG_TEMPMSB 1
aitouares	0:5b6520e71eb6	31	#define DS1820_REG_CNTREMAIN 6
aitouares	0:5b6520e71eb6	32	#define DS1820_REG_CNTPERSEC 7
aitouares	0:5b6520e71eb6	33	#define DS1820_SCRPADMEM_LEN 9 // length of scratchpad memory
aitouares	0:5b6520e71eb6	34
aitouares	0:5b6520e71eb6	35	#define DS1820_ADDR_LEN 8
aitouares	0:5b6520e71eb6	36
aitouares	0:5b6520e71eb6	37
aitouares	0:5b6520e71eb6	38	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	39	/* DS1820 Commands */
aitouares	0:5b6520e71eb6	40	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	41
aitouares	0:5b6520e71eb6	42	#define DS1820_CMD_SEARCHROM 0xF0 // recherche des differents DS1820 et de leur numROMs
aitouares	0:5b6520e71eb6	43	#define DS1820_CMD_READROM 0x33 // idem que SEARCHROM mais utilise pour 1 seul DS1820
aitouares	0:5b6520e71eb6	44	#define DS1820_CMD_MATCHROM 0x55 // permet de communiquer avec un DS1820 en particulier grace a son numROM
aitouares	0:5b6520e71eb6	45	#define DS1820_CMD_SKIPROM 0xCC // permet de communiquer avec tous les DS1820 en meme temps
aitouares	0:5b6520e71eb6	46	#define DS1820_CMD_ALARMSEARCH 0xEC // permet de dialoguer seulement avec les DS1820 qui ont un flag
aitouares	0:5b6520e71eb6	47	#define DS1820_CMD_CONVERTTEMP 0x44 // permet de lancer un convertion de la temperature, le resultat sera stocke dans le scratchpad
aitouares	0:5b6520e71eb6	48	#define DS1820_CMD_WRITESCRPAD 0x4E // permet au MBED d'ecrire deux octets dans le scratchpad dont un dans le registre TH et un dans le registre TL
aitouares	0:5b6520e71eb6	49	#define DS1820_CMD_READSCRPAD 0xBE // permet au MBED de lire le scratchpad
aitouares	0:5b6520e71eb6	50	#define DS1820_CMD_COPYSCRPAD 0x48 // permet de copier le scratchpad et les registres TH, TL stocke dans EEPROM
aitouares	0:5b6520e71eb6	51	#define DS1820_CMD_RECALLEE 0xB8 // rappel les valeur de declenchement de l'alarme
aitouares	0:5b6520e71eb6	52
aitouares	0:5b6520e71eb6	53
aitouares	0:5b6520e71eb6	54	#define DS1820_FAMILY_CODE_DS18B20 0x28
aitouares	0:5b6520e71eb6	55	#define DS1820_FAMILY_CODE_DS18S20 0x10
aitouares	0:5b6520e71eb6	56
aitouares	0:5b6520e71eb6	57	char dowcrc=0; // crc is accumulated in this variable
aitouares	0:5b6520e71eb6	58	// crc lookup table
aitouares	0:5b6520e71eb6	59	char const dscrc_table[] = {
aitouares	0:5b6520e71eb6	60	0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
aitouares	0:5b6520e71eb6	61	157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,
aitouares	0:5b6520e71eb6	62	35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,
aitouares	0:5b6520e71eb6	63	190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
aitouares	0:5b6520e71eb6	64	70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,
aitouares	0:5b6520e71eb6	65	219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,
aitouares	0:5b6520e71eb6	66	101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,
aitouares	0:5b6520e71eb6	67	248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,
aitouares	0:5b6520e71eb6	68	140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
aitouares	0:5b6520e71eb6	69	17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
aitouares	0:5b6520e71eb6	70	175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
aitouares	0:5b6520e71eb6	71	50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
aitouares	0:5b6520e71eb6	72	202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
aitouares	0:5b6520e71eb6	73	87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
aitouares	0:5b6520e71eb6	74	233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
aitouares	0:5b6520e71eb6	75	116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53
aitouares	0:5b6520e71eb6	76	};
aitouares	0:5b6520e71eb6	77
aitouares	0:5b6520e71eb6	78	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	79	bool doneFlag; // declaration d'une variable booleenne "doneFlag"
aitouares	0:5b6520e71eb6	80	char lastDiscrep,numROMs; // declaration des variables lastDiscrep et numROMs
aitouares	0:5b6520e71eb6	81	char RomBytes[DS1820_ADDR_LEN]; // declaration de la variable RomBytes[DS1820_ADDR_LEN]
aitouares	0:5b6520e71eb6	82	char FoundROM[9][8]; // Table of found ROM codes, 8 bytes for each
aitouares	0:5b6520e71eb6	83
aitouares	0:5b6520e71eb6	84
aitouares	0:5b6520e71eb6	85	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	86	/* Low-Level Functions */
aitouares	0:5b6520e71eb6	87	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	88	/*******************************************************************************
aitouares	0:5b6520e71eb6	89	* FUNCTION: ow_reset
aitouares	0:5b6520e71eb6	90	* PURPOSE: Initializes the DS1820 device.
aitouares	0:5b6520e71eb6	91	*
aitouares	0:5b6520e71eb6	92	* INPUT: -
aitouares	0:5b6520e71eb6	93	* OUTPUT: -
aitouares	0:5b6520e71eb6	94	* RETURN: FALSE if at least one device is on the 1-wire bus, TRUE otherwise
aitouares	0:5b6520e71eb6	95	******************************************************************************/
aitouares	0:5b6520e71eb6	96	bool ow_reset(void)
aitouares	0:5b6520e71eb6	97	{
aitouares	0:5b6520e71eb6	98	bool presence;
aitouares	0:5b6520e71eb6	99
aitouares	0:5b6520e71eb6	100	/* reset pulse */
aitouares	0:5b6520e71eb6	101	DQ.output();
aitouares	0:5b6520e71eb6	102	DQ=0;
aitouares	0:5b6520e71eb6	103	wait_us(DS1820_RST_PULSE);
aitouares	0:5b6520e71eb6	104	DQ=1;
aitouares	0:5b6520e71eb6	105
aitouares	0:5b6520e71eb6	106	/* wait until pullup pull 1-wire bus to high */
aitouares	0:5b6520e71eb6	107	wait_us(DS1820_PRESENCE_WAIT);
aitouares	0:5b6520e71eb6	108
aitouares	0:5b6520e71eb6	109	/* get presence pulse */
aitouares	0:5b6520e71eb6	110	DQ.input();
aitouares	0:5b6520e71eb6	111	presence=DQ.read();
aitouares	0:5b6520e71eb6	112
aitouares	0:5b6520e71eb6	113	wait_us(424);
aitouares	0:5b6520e71eb6	114
aitouares	0:5b6520e71eb6	115	return presence;
aitouares	0:5b6520e71eb6	116	}
aitouares	0:5b6520e71eb6	117
aitouares	0:5b6520e71eb6	118	/*******************************************************************************
aitouares	0:5b6520e71eb6	119	* FUNCTION: read_bit
aitouares	0:5b6520e71eb6	120	* PURPOSE: Reads a single bit from the DS1820 device.
aitouares	0:5b6520e71eb6	121	*
aitouares	0:5b6520e71eb6	122	* INPUT: -
aitouares	0:5b6520e71eb6	123	* OUTPUT: -
aitouares	0:5b6520e71eb6	124	* RETURN: bool value of the bit which as been read form the DS1820
aitouares	0:5b6520e71eb6	125	******************************************************************************/
aitouares	0:5b6520e71eb6	126	bool read_bit(void)
aitouares	0:5b6520e71eb6	127	{
aitouares	0:5b6520e71eb6	128	DQ.output();
aitouares	0:5b6520e71eb6	129	DQ=0;
aitouares	0:5b6520e71eb6	130	wait_us(DS1820_MSTR_BITSTART);
aitouares	0:5b6520e71eb6	131	DQ.input();
aitouares	0:5b6520e71eb6	132	DQ.read();
aitouares	0:5b6520e71eb6	133	wait_us(DS1820_BITREAD_DLY);
aitouares	0:5b6520e71eb6	134
aitouares	0:5b6520e71eb6	135	return (DQ);
aitouares	0:5b6520e71eb6	136	}
aitouares	0:5b6520e71eb6	137
aitouares	0:5b6520e71eb6	138	/*******************************************************************************
aitouares	0:5b6520e71eb6	139	* FUNCTION: write_bit
aitouares	0:5b6520e71eb6	140	* PURPOSE: Writes a single bit to the DS1820 device.
aitouares	0:5b6520e71eb6	141	*
aitouares	0:5b6520e71eb6	142	* INPUT: bBit value of bit to be written
aitouares	0:5b6520e71eb6	143	* OUTPUT: -
aitouares	0:5b6520e71eb6	144	* RETURN: -
aitouares	0:5b6520e71eb6	145	******************************************************************************/
aitouares	0:5b6520e71eb6	146	void write_bit(bool bBit)
aitouares	0:5b6520e71eb6	147	{
aitouares	0:5b6520e71eb6	148	DQ.output();
aitouares	0:5b6520e71eb6	149	DQ=0;
aitouares	0:5b6520e71eb6	150	wait_us(DS1820_MSTR_BITSTART);
aitouares	0:5b6520e71eb6	151
aitouares	0:5b6520e71eb6	152	if (bBit != false) DQ=1;
aitouares	0:5b6520e71eb6	153
aitouares	0:5b6520e71eb6	154	wait_us(DS1820_BITWRITE_DLY);
aitouares	0:5b6520e71eb6	155	DQ=1;
aitouares	0:5b6520e71eb6	156
aitouares	0:5b6520e71eb6	157	}
aitouares	0:5b6520e71eb6	158
aitouares	0:5b6520e71eb6	159	/*******************************************************************************
aitouares	0:5b6520e71eb6	160	* FUNCTION: read_byte
aitouares	0:5b6520e71eb6	161	* PURPOSE: Reads a single byte from the DS1820 device.
aitouares	0:5b6520e71eb6	162	*
aitouares	0:5b6520e71eb6	163	* INPUT: -
aitouares	0:5b6520e71eb6	164	* OUTPUT: -
aitouares	0:5b6520e71eb6	165	* RETURN: uint8 byte which has been read from the DS1820
aitouares	0:5b6520e71eb6	166	******************************************************************************/
aitouares	0:5b6520e71eb6	167	char read_byte(void)
aitouares	0:5b6520e71eb6	168	{
aitouares	0:5b6520e71eb6	169	char i;
aitouares	0:5b6520e71eb6	170	char value = 0;
aitouares	0:5b6520e71eb6	171
aitouares	0:5b6520e71eb6	172	for (i=0 ; i < 8; i++)
aitouares	0:5b6520e71eb6	173	{
aitouares	0:5b6520e71eb6	174	if ( read_bit() ) value \|= (1 << i);
aitouares	0:5b6520e71eb6	175	wait_us(120);
aitouares	0:5b6520e71eb6	176	}
aitouares	0:5b6520e71eb6	177	return(value);
aitouares	0:5b6520e71eb6	178	}
aitouares	0:5b6520e71eb6	179
aitouares	0:5b6520e71eb6	180	/*******************************************************************************
aitouares	0:5b6520e71eb6	181	* FUNCTION: write_byte
aitouares	0:5b6520e71eb6	182	* PURPOSE: Writes a single byte to the DS1820 device.
aitouares	0:5b6520e71eb6	183	*
aitouares	0:5b6520e71eb6	184	* INPUT: val_u8 byte to be written
aitouares	0:5b6520e71eb6	185	* OUTPUT: -
aitouares	0:5b6520e71eb6	186	* RETURN: -
aitouares	0:5b6520e71eb6	187	******************************************************************************/
aitouares	0:5b6520e71eb6	188	void write_byte(char val_u8)
aitouares	0:5b6520e71eb6	189	{
aitouares	0:5b6520e71eb6	190	char i;
aitouares	0:5b6520e71eb6	191	char temp;
aitouares	0:5b6520e71eb6	192
aitouares	0:5b6520e71eb6	193	for (i=0; i < 8; i++) /* writes byte, one bit at a time */
aitouares	0:5b6520e71eb6	194	{
aitouares	0:5b6520e71eb6	195	temp = val_u8 >> i; /* shifts val right 'i' spaces */
aitouares	0:5b6520e71eb6	196	temp &= 0x01; /* copy that bit to temp */
aitouares	0:5b6520e71eb6	197	write_bit(temp); /* write bit in temp into */
aitouares	0:5b6520e71eb6	198	}
aitouares	0:5b6520e71eb6	199
aitouares	0:5b6520e71eb6	200	wait_us(105);
aitouares	0:5b6520e71eb6	201	}
aitouares	0:5b6520e71eb6	202	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	203	// One wire crc
aitouares	0:5b6520e71eb6	204	char ow_crc(char x)
aitouares	0:5b6520e71eb6	205	{
aitouares	0:5b6520e71eb6	206	dowcrc = dscrc_table[dowcrc^x];
aitouares	0:5b6520e71eb6	207	return dowcrc;
aitouares	0:5b6520e71eb6	208	}
aitouares	0:5b6520e71eb6	209	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	210	/* API Interface */
aitouares	0:5b6520e71eb6	211	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	212
aitouares	0:5b6520e71eb6	213	/*******************************************************************************
aitouares	0:5b6520e71eb6	214	* FUNCTION: DS1820_AddrDevice
aitouares	0:5b6520e71eb6	215	* PURPOSE: Addresses a single or all devices on the 1-wire bus.
aitouares	0:5b6520e71eb6	216	*
aitouares	0:5b6520e71eb6	217	* INPUT: nAddrMethod use DS1820_CMD_MATCHROM to select a single
aitouares	0:5b6520e71eb6	218	* device or DS1820_CMD_SKIPROM to select all
aitouares	0:5b6520e71eb6	219	* OUTPUT: -
aitouares	0:5b6520e71eb6	220	* RETURN: -
aitouares	0:5b6520e71eb6	221	******************************************************************************/
aitouares	0:5b6520e71eb6	222	void DS1820_AddrDevice(char nAddrMethod)
aitouares	0:5b6520e71eb6	223	{
aitouares	0:5b6520e71eb6	224	char i;
aitouares	0:5b6520e71eb6	225
aitouares	0:5b6520e71eb6	226	if (nAddrMethod == DS1820_CMD_MATCHROM)
aitouares	0:5b6520e71eb6	227	{
aitouares	0:5b6520e71eb6	228	write_byte(DS1820_CMD_MATCHROM); /* address single devices on bus */
aitouares	0:5b6520e71eb6	229	for (i = 0; i < DS1820_ADDR_LEN; i ++)
aitouares	0:5b6520e71eb6	230	write_byte(RomBytes[i]);
aitouares	0:5b6520e71eb6	231	}
aitouares	0:5b6520e71eb6	232	else
aitouares	0:5b6520e71eb6	233	write_byte(DS1820_CMD_SKIPROM); /* address all devices on bus */
aitouares	0:5b6520e71eb6	234	}
aitouares	0:5b6520e71eb6	235
aitouares	0:5b6520e71eb6	236	/*******************************************************************************
aitouares	0:5b6520e71eb6	237	* FUNCTION: Next
aitouares	0:5b6520e71eb6	238	* PURPOSE: Finds next device connected to the 1-wire bus.
aitouares	0:5b6520e71eb6	239	*
aitouares	0:5b6520e71eb6	240	* INPUT: -
aitouares	0:5b6520e71eb6	241	* OUTPUT: RomBytes[] ROM code of the next device
aitouares	0:5b6520e71eb6	242	* RETURN: bool TRUE if there are more devices on the 1-wire
aitouares	0:5b6520e71eb6	243	* bus, FALSE otherwise
aitouares	0:5b6520e71eb6	244	******************************************************************************/
aitouares	0:5b6520e71eb6	245	bool Next(void)
aitouares	0:5b6520e71eb6	246	{
aitouares	0:5b6520e71eb6	247	char x;
aitouares	0:5b6520e71eb6	248	char n;
aitouares	0:5b6520e71eb6	249	char k = 1;
aitouares	0:5b6520e71eb6	250	char m = 1;
aitouares	0:5b6520e71eb6	251	char discrepMarker = 0;
aitouares	0:5b6520e71eb6	252	bool g;
aitouares	0:5b6520e71eb6	253	bool flag;
aitouares	0:5b6520e71eb6	254	bool nxt = false;
aitouares	0:5b6520e71eb6	255
aitouares	0:5b6520e71eb6	256	/* init ROM address */
aitouares	0:5b6520e71eb6	257	for (n=0; n < 8; n ++)
aitouares	0:5b6520e71eb6	258	RomBytes[n] = 0x00;
aitouares	0:5b6520e71eb6	259
aitouares	0:5b6520e71eb6	260	flag = ow_reset(); /* reset the 1-wire */
aitouares	0:5b6520e71eb6	261
aitouares	0:5b6520e71eb6	262	if (flag \|\| doneFlag) /* no device found */
aitouares	0:5b6520e71eb6	263	{
aitouares	0:5b6520e71eb6	264	lastDiscrep = 0; /* reset the search */
aitouares	0:5b6520e71eb6	265	return false;
aitouares	0:5b6520e71eb6	266	}
aitouares	0:5b6520e71eb6	267
aitouares	0:5b6520e71eb6	268	/* send search rom command */
aitouares	0:5b6520e71eb6	269	write_byte(DS1820_CMD_SEARCHROM);
aitouares	0:5b6520e71eb6	270
aitouares	0:5b6520e71eb6	271	n = 0;
aitouares	0:5b6520e71eb6	272	do
aitouares	0:5b6520e71eb6	273	{
aitouares	0:5b6520e71eb6	274	x = 0;
aitouares	0:5b6520e71eb6	275
aitouares	0:5b6520e71eb6	276	/* read bit */
aitouares	0:5b6520e71eb6	277	if ( read_bit() == 1 ) x = 2;
aitouares	0:5b6520e71eb6	278	wait_us(120);
aitouares	0:5b6520e71eb6	279
aitouares	0:5b6520e71eb6	280	/* read bit complement */
aitouares	0:5b6520e71eb6	281	if ( read_bit() == 1 ) x \|= 1;
aitouares	0:5b6520e71eb6	282	wait_us(120);
aitouares	0:5b6520e71eb6	283
aitouares	0:5b6520e71eb6	284	/* description for values of x: */
aitouares	0:5b6520e71eb6	285	/* 00 There are devices connected to the bus which have conflicting */
aitouares	0:5b6520e71eb6	286	/* bits in the current ROM code bit position. */
aitouares	0:5b6520e71eb6	287	/* 01 All devices connected to the bus have a 0 in this bit position. */
aitouares	0:5b6520e71eb6	288	/* 10 All devices connected to the bus have a 1 in this bit position. */
aitouares	0:5b6520e71eb6	289	/* 11 There are no devices connected to the 1-wire bus. */
aitouares	0:5b6520e71eb6	290
aitouares	0:5b6520e71eb6	291	/* if there are no devices on the bus */
aitouares	0:5b6520e71eb6	292	if (x == 3) break;
aitouares	0:5b6520e71eb6	293	else
aitouares	0:5b6520e71eb6	294	{
aitouares	0:5b6520e71eb6	295	/* devices have the same logical value at this position */
aitouares	0:5b6520e71eb6	296	if (x > 0) g = (bool)(x >> 1);// get bit value
aitouares	0:5b6520e71eb6	297	/* devices have confilcting bits in the current ROM code */
aitouares	0:5b6520e71eb6	298	else
aitouares	0:5b6520e71eb6	299	{
aitouares	0:5b6520e71eb6	300	/* if there was a conflict on the last iteration */
aitouares	0:5b6520e71eb6	301	if (m < lastDiscrep)
aitouares	0:5b6520e71eb6	302	/* take same bit as in last iteration */
aitouares	0:5b6520e71eb6	303	g = ( (RomBytes[n] & k) > 0 );
aitouares	0:5b6520e71eb6	304	else
aitouares	0:5b6520e71eb6	305	g = (m == lastDiscrep);
aitouares	0:5b6520e71eb6	306
aitouares	0:5b6520e71eb6	307	if (g == 0)
aitouares	0:5b6520e71eb6	308	discrepMarker = m;
aitouares	0:5b6520e71eb6	309	}
aitouares	0:5b6520e71eb6	310
aitouares	0:5b6520e71eb6	311	/* store bit in ROM address */
aitouares	0:5b6520e71eb6	312	if (g ==1)
aitouares	0:5b6520e71eb6	313	RomBytes[n] \|= k;
aitouares	0:5b6520e71eb6	314	else
aitouares	0:5b6520e71eb6	315	RomBytes[n] &= ~k;
aitouares	0:5b6520e71eb6	316
aitouares	0:5b6520e71eb6	317	write_bit(g);
aitouares	0:5b6520e71eb6	318
aitouares	0:5b6520e71eb6	319	/* increment bit position */
aitouares	0:5b6520e71eb6	320	m ++;
aitouares	0:5b6520e71eb6	321
aitouares	0:5b6520e71eb6	322	/* calculate next mask value */
aitouares	0:5b6520e71eb6	323	k = k << 1;
aitouares	0:5b6520e71eb6	324
aitouares	0:5b6520e71eb6	325	/* check if this byte has finished */
aitouares	0:5b6520e71eb6	326	if (k == 0)
aitouares	0:5b6520e71eb6	327	{
aitouares	0:5b6520e71eb6	328	ow_crc(RomBytes[n]); // Accumulate the crc
aitouares	0:5b6520e71eb6	329	n ++; /* advance to next byte of ROM mask */
aitouares	0:5b6520e71eb6	330	k = 1; /* update mask */
aitouares	0:5b6520e71eb6	331	}
aitouares	0:5b6520e71eb6	332	}
aitouares	0:5b6520e71eb6	333	} while (n < DS1820_ADDR_LEN);
aitouares	0:5b6520e71eb6	334
aitouares	0:5b6520e71eb6	335
aitouares	0:5b6520e71eb6	336	/* if search was unsuccessful then */
aitouares	0:5b6520e71eb6	337	if ((m < 65) \|\|dowcrc)
aitouares	0:5b6520e71eb6	338	// if (m < 65 )
aitouares	0:5b6520e71eb6	339	/* reset the last discrepancy to 0 */
aitouares	0:5b6520e71eb6	340	lastDiscrep = 0;
aitouares	0:5b6520e71eb6	341	else
aitouares	0:5b6520e71eb6	342	{
aitouares	0:5b6520e71eb6	343	/* search was successful */
aitouares	0:5b6520e71eb6	344	lastDiscrep = discrepMarker;
aitouares	0:5b6520e71eb6	345	doneFlag = (lastDiscrep == 0);
aitouares	0:5b6520e71eb6	346
aitouares	0:5b6520e71eb6	347	/* indicates search is not complete yet, more parts remain */
aitouares	0:5b6520e71eb6	348	nxt = true;
aitouares	0:5b6520e71eb6	349	}
aitouares	0:5b6520e71eb6	350	return nxt;
aitouares	0:5b6520e71eb6	351	}
aitouares	0:5b6520e71eb6	352
aitouares	0:5b6520e71eb6	353	/*******************************************************************************
aitouares	0:5b6520e71eb6	354	* FUNCTION: First
aitouares	0:5b6520e71eb6	355	* PURPOSE: Starts the device search on the 1-wire bus.
aitouares	0:5b6520e71eb6	356	*
aitouares	0:5b6520e71eb6	357	* INPUT: -
aitouares	0:5b6520e71eb6	358	* OUTPUT: RomBytes[] ROM code of the first device
aitouares	0:5b6520e71eb6	359	* RETURN: bool TRUE if there are more devices on the 1-wire
aitouares	0:5b6520e71eb6	360	* bus, FALSE otherwise
aitouares	0:5b6520e71eb6	361	******************************************************************************/
aitouares	0:5b6520e71eb6	362	bool First(void)
aitouares	0:5b6520e71eb6	363	{
aitouares	0:5b6520e71eb6	364	lastDiscrep = 0;
aitouares	0:5b6520e71eb6	365	doneFlag = false;
aitouares	0:5b6520e71eb6	366
aitouares	0:5b6520e71eb6	367	return ( Next() );
aitouares	0:5b6520e71eb6	368	}
aitouares	0:5b6520e71eb6	369	/* -------------------------------------------------------------------------- */
aitouares	0:5b6520e71eb6	370	void FindDevices(void)
aitouares	0:5b6520e71eb6	371	{
aitouares	0:5b6520e71eb6	372	char m;
aitouares	0:5b6520e71eb6	373	if(!ow_reset())
aitouares	0:5b6520e71eb6	374	{
aitouares	0:5b6520e71eb6	375	if(First()) // Begins when at least one part found
aitouares	0:5b6520e71eb6	376	{
aitouares	0:5b6520e71eb6	377	numROMs = 0;
aitouares	0:5b6520e71eb6	378	do
aitouares	0:5b6520e71eb6	379	{
aitouares	0:5b6520e71eb6	380	numROMs++;
aitouares	0:5b6520e71eb6	381	for (m=0;m<8;m++)
aitouares	0:5b6520e71eb6	382	{
aitouares	0:5b6520e71eb6	383	FoundROM[numROMs-1][m] = RomBytes[m];
aitouares	0:5b6520e71eb6	384	}
aitouares	0:5b6520e71eb6	385	} while (Next()&&(numROMs<10)); // Continues until no additional
aitouares	0:5b6520e71eb6	386	}
aitouares	0:5b6520e71eb6	387	}
aitouares	0:5b6520e71eb6	388
aitouares	0:5b6520e71eb6	389	}
aitouares	0:5b6520e71eb6	390	//******************************************************************************
aitouares	0:5b6520e71eb6	391	// Sends Match ROM command to bus then device address
aitouares	0:5b6520e71eb6	392	char Send_MatchRom(char actNumROM)
aitouares	0:5b6520e71eb6	393	{
aitouares	0:5b6520e71eb6	394	char i;
aitouares	0:5b6520e71eb6	395	if (ow_reset()) return false; // 0 if device present
aitouares	0:5b6520e71eb6	396	write_byte(0x55); // Match ROM
aitouares	0:5b6520e71eb6	397
aitouares	0:5b6520e71eb6	398	for (i=0;i<8;i++)
aitouares	0:5b6520e71eb6	399	{
aitouares	0:5b6520e71eb6	400	write_byte(FoundROM[actNumROM][i]); // Send ROM code
aitouares	0:5b6520e71eb6	401	}
aitouares	0:5b6520e71eb6	402
aitouares	0:5b6520e71eb6	403	return true;
aitouares	0:5b6520e71eb6	404	}
aitouares	0:5b6520e71eb6	405	//******************************************************************************
aitouares	0:5b6520e71eb6	406	void Read_ROMCode(void)
aitouares	0:5b6520e71eb6	407	{
aitouares	0:5b6520e71eb6	408	char n;
aitouares	0:5b6520e71eb6	409	char dat[9];
aitouares	0:5b6520e71eb6	410
aitouares	0:5b6520e71eb6	411	ow_reset();
aitouares	0:5b6520e71eb6	412	write_byte(0x33);
aitouares	0:5b6520e71eb6	413	for (n=0;n<8;n++){dat[n]=read_byte();}
aitouares	0:5b6520e71eb6	414
aitouares	0:5b6520e71eb6	415	pc.printf("\f%X%X%X%X\n%X%X%X%X",dat[0],dat[1],dat[2],dat[3],dat[4],dat[5],
aitouares	0:5b6520e71eb6	416	dat[6],dat[7]);
aitouares	0:5b6520e71eb6	417
aitouares	0:5b6520e71eb6	418	wait_ms(5000);
aitouares	0:5b6520e71eb6	419	}
aitouares	0:5b6520e71eb6	420	/*******************************************************************************
aitouares	0:5b6520e71eb6	421	* FUNCTION: DS1820_WriteEEPROM
aitouares	0:5b6520e71eb6	422	* PURPOSE: Writes to the DS1820 EEPROM memory (2 bytes available).
aitouares	0:5b6520e71eb6	423	*
aitouares	0:5b6520e71eb6	424	* INPUT: nTHigh high byte of EEPROM
aitouares	0:5b6520e71eb6	425	* nTLow low byte of EEPROM
aitouares	0:5b6520e71eb6	426	* OUTPUT: -
aitouares	0:5b6520e71eb6	427	* RETURN: -
aitouares	0:5b6520e71eb6	428	******************************************************************************/
aitouares	0:5b6520e71eb6	429	void DS1820_WriteEEPROM(char nTHigh, char nTLow)
aitouares	0:5b6520e71eb6	430	{
aitouares	0:5b6520e71eb6	431	/* --- write to scratchpad ----------------------------------------------- */
aitouares	0:5b6520e71eb6	432	ow_reset(); // appel de la fonction ow_reset
aitouares	0:5b6520e71eb6	433	DS1820_AddrDevice(DS1820_CMD_MATCHROM);
aitouares	0:5b6520e71eb6	434	write_byte(DS1820_CMD_WRITESCRPAD); // debut conversion
aitouares	0:5b6520e71eb6	435	write_byte(nTHigh);
aitouares	0:5b6520e71eb6	436	write_byte(nTLow);
aitouares	0:5b6520e71eb6	437	wait_us(10); // attendre 10ms
aitouares	0:5b6520e71eb6	438	ow_reset(); // appel de la fonction ow_reset
aitouares	0:5b6520e71eb6	439	DS1820_AddrDevice(DS1820_CMD_MATCHROM);
aitouares	0:5b6520e71eb6	440	write_byte(DS1820_CMD_COPYSCRPAD); // start conversion
aitouares	0:5b6520e71eb6	441	G__MOS_P=0; // "strong pullup"
aitouares	0:5b6520e71eb6	442	wait_ms(10); // attendre 10 ms
aitouares	0:5b6520e71eb6	443	G__MOS_P=1; // "strong pullup"
aitouares	0:5b6520e71eb6	444	}
aitouares	0:5b6520e71eb6	445
aitouares	0:5b6520e71eb6	446	/*******************************************************************************
aitouares	0:5b6520e71eb6	447	* FUNCTION: DS1820_GetTemp
aitouares	0:5b6520e71eb6	448	* PURPOSE: Get temperature value from single DS1820 device.
aitouares	0:5b6520e71eb6	449	*
aitouares	0:5b6520e71eb6	450	* Scratchpad Memory Layout
aitouares	0:5b6520e71eb6	451	* Byte Register
aitouares	0:5b6520e71eb6	452	* 0 Temperature_LSB
aitouares	0:5b6520e71eb6	453	* 1 Temperature_MSB
aitouares	0:5b6520e71eb6	454	* 2 Temp Alarm High / User Byte 1
aitouares	0:5b6520e71eb6	455	* 3 Temp Alarm Low / User Byte 2
aitouares	0:5b6520e71eb6	456	* 4 Reserved
aitouares	0:5b6520e71eb6	457	* 5 Reserved
aitouares	0:5b6520e71eb6	458	* 6 Count_Remain
aitouares	0:5b6520e71eb6	459	* 7 Count_per_C
aitouares	0:5b6520e71eb6	460	* 8 CRC
aitouares	0:5b6520e71eb6	461	*
aitouares	0:5b6520e71eb6	462	* Temperature calculation for DS18S20 (Family Code 0x10):
aitouares	0:5b6520e71eb6	463	* =======================================================
aitouares	0:5b6520e71eb6	464	* (Count_per_C - Count_Remain)
aitouares	0:5b6520e71eb6	465	* Temperature = temp_read - 0.25 + ----------------------------
aitouares	0:5b6520e71eb6	466	* Count_per_C
aitouares	0:5b6520e71eb6	467	*
aitouares	0:5b6520e71eb6	468	* Where temp_read is the value from the temp_MSB and temp_LSB with
aitouares	0:5b6520e71eb6	469	* the least significant bit removed (the 0.5C bit).
aitouares	0:5b6520e71eb6	470	*
aitouares	0:5b6520e71eb6	471	*
aitouares	0:5b6520e71eb6	472	* Temperature calculation for DS18B20 (Family Code 0x28):
aitouares	0:5b6520e71eb6	473	* =======================================================
aitouares	0:5b6520e71eb6	474	* bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
aitouares	0:5b6520e71eb6	475	* LSB 2^3 2^2 2^1 2^0 2^-1 2^-2 2^-3 2^-4
aitouares	0:5b6520e71eb6	476	* bit15 bit14 bit13 bit12 bit3 bit2 bit1 bit0
aitouares	0:5b6520e71eb6	477	* MSB S S S S S 2^6 2^5 2^4
aitouares	0:5b6520e71eb6	478	*
aitouares	0:5b6520e71eb6	479	* The temperature data is stored as a 16-bit sign-extended two�s
aitouares	0:5b6520e71eb6	480	* complement number in the temperature register. The sign bits (S)
aitouares	0:5b6520e71eb6	481	* indicate if the temperature is positive or negative: for
aitouares	0:5b6520e71eb6	482	* positive numbers S = 0 and for negative numbers S = 1.
aitouares	0:5b6520e71eb6	483	*
aitouares	0:5b6520e71eb6	484	* RETURN: float
aitouares	0:5b6520e71eb6	485	******************************************************************************/
aitouares	0:5b6520e71eb6	486	float DS1820_GetTemp(void) //fonction capture de la temperature
aitouares	0:5b6520e71eb6	487	{
aitouares	0:5b6520e71eb6	488	char i; //declaration de la variable i
aitouares	0:5b6520e71eb6	489	char scrpad[DS1820_SCRPADMEM_LEN]; //declaration de la variable scrpad[DS1820_SCRPADMEM_LEN]
aitouares	0:5b6520e71eb6	490	signed char temp_read; //declaration de la variable signe temp_read
aitouares	0:5b6520e71eb6	491	float temperature; //declaration de la variable flotante temperature
aitouares	0:5b6520e71eb6	492
aitouares	0:5b6520e71eb6	493	/* --- start temperature conversion -------------------------------------- */
aitouares	0:5b6520e71eb6	494	ow_reset();
aitouares	0:5b6520e71eb6	495	DS1820_AddrDevice(DS1820_CMD_MATCHROM); /* address the device */
aitouares	0:5b6520e71eb6	496	DQ.output(); //DQ en sortie
aitouares	0:5b6520e71eb6	497	DQ=1; //DQ � 1
aitouares	0:5b6520e71eb6	498	write_byte(DS1820_CMD_CONVERTTEMP); /* start conversion */
aitouares	0:5b6520e71eb6	499	G__MOS_P=0; //"strong pullup"
aitouares	0:5b6520e71eb6	500	/* wait for temperature conversion */
aitouares	0:5b6520e71eb6	501	wait_ms(750); // attendre 0.75s
aitouares	0:5b6520e71eb6	502	G__MOS_P=1; //"strong pullup"
aitouares	0:5b6520e71eb6	503
aitouares	0:5b6520e71eb6	504	/* --- read sratchpad ---------------------------------------------------- */
aitouares	0:5b6520e71eb6	505	ow_reset();
aitouares	0:5b6520e71eb6	506	DS1820_AddrDevice(DS1820_CMD_MATCHROM); /* address the device */
aitouares	0:5b6520e71eb6	507	write_byte(DS1820_CMD_READSCRPAD); /* read scratch pad */
aitouares	0:5b6520e71eb6	508
aitouares	0:5b6520e71eb6	509	/* read scratch pad data */
aitouares	0:5b6520e71eb6	510	for (i=0; i < DS1820_SCRPADMEM_LEN; i++) // boucle for : i=0 puis on l'incremante jusqu'a i < DS1820_SCRPADMEM_LEN
aitouares	0:5b6520e71eb6	511	scrpad[i] = read_byte();
aitouares	0:5b6520e71eb6	512
aitouares	0:5b6520e71eb6	513	/* --- calculate temperature --------------------------------------------- */
aitouares	0:5b6520e71eb6	514
aitouares	0:5b6520e71eb6	515	if (RomBytes[0] == DS1820_FAMILY_CODE_DS18S20)
aitouares	0:5b6520e71eb6	516	{
aitouares	0:5b6520e71eb6	517	/////////////////////// precision O,5 degC //////////////////////////////////////
aitouares	0:5b6520e71eb6	518	/*// temp = (signed int) make16(scrpad[1],scrpad[0]);
aitouares	0:5b6520e71eb6	519	temp = (signed int) ((int)scrpad[1]<<8 \| (int)scrpad[0]);
aitouares	0:5b6520e71eb6	520	temperature =(float)temp/2;*/
aitouares	0:5b6520e71eb6	521	/////////////////////////////////////////////////////////////////////////////////
aitouares	0:5b6520e71eb6	522
aitouares	0:5b6520e71eb6	523	////////////////////// precision O,1 deg ////////////////////////////////////////
aitouares	0:5b6520e71eb6	524	//...calcul....
aitouares	0:5b6520e71eb6	525	temp_read=(signed char)(((int)scrpad[1]<<8 \| (int)scrpad[0])>>1);
aitouares	0:5b6520e71eb6	526	temperature=(float)(temp_read);
aitouares	0:5b6520e71eb6	527	temperature = temperature + 0.75 - (float)(scrpad[6]/(float)scrpad[7]);
aitouares	0:5b6520e71eb6	528	////////////////////////////////////////////////////////////////////////////////
aitouares	0:5b6520e71eb6	529	}
aitouares	0:5b6520e71eb6	530	else//ds18b20
aitouares	0:5b6520e71eb6	531	temperature =((float) (signed int)((int)scrpad[1]<<8 \| (int)scrpad[0]))/16;
aitouares	0:5b6520e71eb6	532
aitouares	0:5b6520e71eb6	533	return (temperature);
aitouares	0:5b6520e71eb6	534	}
aitouares	0:5b6520e71eb6	535	//******************************************************************************

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	26 Apr 2012
Imports:	69
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

DS18S20.h@0:5b6520e71eb6, 2012-04-26 (annotated)

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