cevrero jeremy
/
1_Programme_principal
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DS18S20.h@0:40a613e7ba83, 2012-05-01 (annotated)
- Committer:
- jeremycevrero
- Date:
- Tue May 01 21:29:55 2012 +0000
- Revision:
- 0:40a613e7ba83
Who changed what in which revision?
| User | Revision | Line number | New contents of line |
|---|---|---|---|
| jeremycevrero | 0:40a613e7ba83 | 1 | /*** D'apres : ********************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 2 | * |
| jeremycevrero | 0:40a613e7ba83 | 3 | * FILENAME: ds1820.h |
| jeremycevrero | 0:40a613e7ba83 | 4 | * DATE: 25.02.2005 |
| jeremycevrero | 0:40a613e7ba83 | 5 | * AUTHOR: Christian Stadler |
| jeremycevrero | 0:40a613e7ba83 | 6 | * |
| jeremycevrero | 0:40a613e7ba83 | 7 | * DESCRIPTION: Driver for DS1820 1-Wire Temperature sensor (Dallas) |
| jeremycevrero | 0:40a613e7ba83 | 8 | * |
| jeremycevrero | 0:40a613e7ba83 | 9 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 10 | #include "mbed.h" |
| jeremycevrero | 0:40a613e7ba83 | 11 | DigitalInOut DQ (p18); // broche DQ relie a la broche p15 du MBED |
| jeremycevrero | 0:40a613e7ba83 | 12 | DigitalOut G__MOS_P (p17); |
| jeremycevrero | 0:40a613e7ba83 | 13 | Serial pc(USBTX, USBRX); // tx, rx |
| jeremycevrero | 0:40a613e7ba83 | 14 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 15 | /* DS1820 Timing Parameters */ |
| jeremycevrero | 0:40a613e7ba83 | 16 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 17 | #define DS1820_RST_PULSE 480 /* master reset pulse time in [us] */ |
| jeremycevrero | 0:40a613e7ba83 | 18 | #define DS1820_MSTR_BITSTART 2 /* delay time for bit start by master */ |
| jeremycevrero | 0:40a613e7ba83 | 19 | #define DS1820_PRESENCE_WAIT 40 /* delay after master reset pulse in [us] */ |
| jeremycevrero | 0:40a613e7ba83 | 20 | #define DS1820_PRESENCE_FIN 480 /* dealy after reading of presence pulse [us] */ |
| jeremycevrero | 0:40a613e7ba83 | 21 | #define DS1820_BITREAD_DLY 5 /* bit read delay */ |
| jeremycevrero | 0:40a613e7ba83 | 22 | #define DS1820_BITWRITE_DLY 100 /* bit write delay */ |
| jeremycevrero | 0:40a613e7ba83 | 23 | |
| jeremycevrero | 0:40a613e7ba83 | 24 | |
| jeremycevrero | 0:40a613e7ba83 | 25 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 26 | /* DS1820 Registers */ |
| jeremycevrero | 0:40a613e7ba83 | 27 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 28 | |
| jeremycevrero | 0:40a613e7ba83 | 29 | #define DS1820_REG_TEMPLSB 0 |
| jeremycevrero | 0:40a613e7ba83 | 30 | #define DS1820_REG_TEMPMSB 1 |
| jeremycevrero | 0:40a613e7ba83 | 31 | #define DS1820_REG_CNTREMAIN 6 |
| jeremycevrero | 0:40a613e7ba83 | 32 | #define DS1820_REG_CNTPERSEC 7 |
| jeremycevrero | 0:40a613e7ba83 | 33 | #define DS1820_SCRPADMEM_LEN 9 // length of scratchpad memory |
| jeremycevrero | 0:40a613e7ba83 | 34 | |
| jeremycevrero | 0:40a613e7ba83 | 35 | #define DS1820_ADDR_LEN 8 |
| jeremycevrero | 0:40a613e7ba83 | 36 | |
| jeremycevrero | 0:40a613e7ba83 | 37 | |
| jeremycevrero | 0:40a613e7ba83 | 38 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 39 | /* DS1820 Commands */ |
| jeremycevrero | 0:40a613e7ba83 | 40 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 41 | |
| jeremycevrero | 0:40a613e7ba83 | 42 | #define DS1820_CMD_SEARCHROM 0xF0 // recherche des differents DS1820 et de leur numROMs |
| jeremycevrero | 0:40a613e7ba83 | 43 | #define DS1820_CMD_READROM 0x33 // idem que SEARCHROM mais utilise pour 1 seul DS1820 |
| jeremycevrero | 0:40a613e7ba83 | 44 | #define DS1820_CMD_MATCHROM 0x55 // permet de communiquer avec un DS1820 en particulier grace a son numROM |
| jeremycevrero | 0:40a613e7ba83 | 45 | #define DS1820_CMD_SKIPROM 0xCC // permet de communiquer avec tous les DS1820 en meme temps |
| jeremycevrero | 0:40a613e7ba83 | 46 | #define DS1820_CMD_ALARMSEARCH 0xEC // permet de dialoguer seulement avec les DS1820 qui ont un flag |
| jeremycevrero | 0:40a613e7ba83 | 47 | #define DS1820_CMD_CONVERTTEMP 0x44 // permet de lancer un convertion de la temperature, le resultat sera stocke dans le scratchpad |
| jeremycevrero | 0:40a613e7ba83 | 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 |
| jeremycevrero | 0:40a613e7ba83 | 49 | #define DS1820_CMD_READSCRPAD 0xBE // permet au MBED de lire le scratchpad |
| jeremycevrero | 0:40a613e7ba83 | 50 | #define DS1820_CMD_COPYSCRPAD 0x48 // permet de copier le scratchpad et les registres TH, TL stocke dans EEPROM |
| jeremycevrero | 0:40a613e7ba83 | 51 | #define DS1820_CMD_RECALLEE 0xB8 // rappel les valeur de declenchement de l'alarme |
| jeremycevrero | 0:40a613e7ba83 | 52 | |
| jeremycevrero | 0:40a613e7ba83 | 53 | |
| jeremycevrero | 0:40a613e7ba83 | 54 | #define DS1820_FAMILY_CODE_DS18B20 0x28 |
| jeremycevrero | 0:40a613e7ba83 | 55 | #define DS1820_FAMILY_CODE_DS18S20 0x10 |
| jeremycevrero | 0:40a613e7ba83 | 56 | |
| jeremycevrero | 0:40a613e7ba83 | 57 | char dowcrc=0; // crc is accumulated in this variable |
| jeremycevrero | 0:40a613e7ba83 | 58 | // crc lookup table |
| jeremycevrero | 0:40a613e7ba83 | 59 | char const dscrc_table[] = { |
| jeremycevrero | 0:40a613e7ba83 | 60 | 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65, |
| jeremycevrero | 0:40a613e7ba83 | 61 | 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220, |
| jeremycevrero | 0:40a613e7ba83 | 62 | 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98, |
| jeremycevrero | 0:40a613e7ba83 | 63 | 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255, |
| jeremycevrero | 0:40a613e7ba83 | 64 | 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7, |
| jeremycevrero | 0:40a613e7ba83 | 65 | 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154, |
| jeremycevrero | 0:40a613e7ba83 | 66 | 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36, |
| jeremycevrero | 0:40a613e7ba83 | 67 | 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185, |
| jeremycevrero | 0:40a613e7ba83 | 68 | 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205, |
| jeremycevrero | 0:40a613e7ba83 | 69 | 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80, |
| jeremycevrero | 0:40a613e7ba83 | 70 | 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238, |
| jeremycevrero | 0:40a613e7ba83 | 71 | 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115, |
| jeremycevrero | 0:40a613e7ba83 | 72 | 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139, |
| jeremycevrero | 0:40a613e7ba83 | 73 | 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22, |
| jeremycevrero | 0:40a613e7ba83 | 74 | 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168, |
| jeremycevrero | 0:40a613e7ba83 | 75 | 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53 |
| jeremycevrero | 0:40a613e7ba83 | 76 | }; |
| jeremycevrero | 0:40a613e7ba83 | 77 | |
| jeremycevrero | 0:40a613e7ba83 | 78 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 79 | bool doneFlag; // declaration d'une variable booleenne "doneFlag" |
| jeremycevrero | 0:40a613e7ba83 | 80 | char lastDiscrep,numROMs; // declaration des variables lastDiscrep et numROMs |
| jeremycevrero | 0:40a613e7ba83 | 81 | char RomBytes[DS1820_ADDR_LEN]; // declaration de la variable RomBytes[DS1820_ADDR_LEN] |
| jeremycevrero | 0:40a613e7ba83 | 82 | char FoundROM[9][8]; // Table of found ROM codes, 8 bytes for each |
| jeremycevrero | 0:40a613e7ba83 | 83 | float temperature;// declaration de la variable |
| jeremycevrero | 0:40a613e7ba83 | 84 | |
| jeremycevrero | 0:40a613e7ba83 | 85 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 86 | /* Low-Level Functions */ |
| jeremycevrero | 0:40a613e7ba83 | 87 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 88 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 89 | * FUNCTION: ow_reset |
| jeremycevrero | 0:40a613e7ba83 | 90 | * PURPOSE: Initializes the DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 91 | * |
| jeremycevrero | 0:40a613e7ba83 | 92 | * INPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 93 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 94 | * RETURN: FALSE if at least one device is on the 1-wire bus, TRUE otherwise |
| jeremycevrero | 0:40a613e7ba83 | 95 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 96 | bool ow_reset(void) |
| jeremycevrero | 0:40a613e7ba83 | 97 | { |
| jeremycevrero | 0:40a613e7ba83 | 98 | bool presence; |
| jeremycevrero | 0:40a613e7ba83 | 99 | |
| jeremycevrero | 0:40a613e7ba83 | 100 | /* reset pulse */ |
| jeremycevrero | 0:40a613e7ba83 | 101 | DQ.output(); |
| jeremycevrero | 0:40a613e7ba83 | 102 | DQ=0; |
| jeremycevrero | 0:40a613e7ba83 | 103 | wait_us(DS1820_RST_PULSE); |
| jeremycevrero | 0:40a613e7ba83 | 104 | DQ=1; |
| jeremycevrero | 0:40a613e7ba83 | 105 | |
| jeremycevrero | 0:40a613e7ba83 | 106 | /* wait until pullup pull 1-wire bus to high */ |
| jeremycevrero | 0:40a613e7ba83 | 107 | wait_us(DS1820_PRESENCE_WAIT); |
| jeremycevrero | 0:40a613e7ba83 | 108 | |
| jeremycevrero | 0:40a613e7ba83 | 109 | /* get presence pulse */ |
| jeremycevrero | 0:40a613e7ba83 | 110 | DQ.input(); |
| jeremycevrero | 0:40a613e7ba83 | 111 | presence=DQ.read(); |
| jeremycevrero | 0:40a613e7ba83 | 112 | |
| jeremycevrero | 0:40a613e7ba83 | 113 | wait_us(424); |
| jeremycevrero | 0:40a613e7ba83 | 114 | |
| jeremycevrero | 0:40a613e7ba83 | 115 | return presence; |
| jeremycevrero | 0:40a613e7ba83 | 116 | } |
| jeremycevrero | 0:40a613e7ba83 | 117 | |
| jeremycevrero | 0:40a613e7ba83 | 118 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 119 | * FUNCTION: read_bit |
| jeremycevrero | 0:40a613e7ba83 | 120 | * PURPOSE: Reads a single bit from the DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 121 | * |
| jeremycevrero | 0:40a613e7ba83 | 122 | * INPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 123 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 124 | * RETURN: bool value of the bit which as been read form the DS1820 |
| jeremycevrero | 0:40a613e7ba83 | 125 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 126 | bool read_bit(void) |
| jeremycevrero | 0:40a613e7ba83 | 127 | { |
| jeremycevrero | 0:40a613e7ba83 | 128 | DQ.output(); |
| jeremycevrero | 0:40a613e7ba83 | 129 | DQ=0; |
| jeremycevrero | 0:40a613e7ba83 | 130 | wait_us(DS1820_MSTR_BITSTART); |
| jeremycevrero | 0:40a613e7ba83 | 131 | DQ.input(); |
| jeremycevrero | 0:40a613e7ba83 | 132 | DQ.read(); |
| jeremycevrero | 0:40a613e7ba83 | 133 | wait_us(DS1820_BITREAD_DLY); |
| jeremycevrero | 0:40a613e7ba83 | 134 | |
| jeremycevrero | 0:40a613e7ba83 | 135 | return (DQ); |
| jeremycevrero | 0:40a613e7ba83 | 136 | } |
| jeremycevrero | 0:40a613e7ba83 | 137 | |
| jeremycevrero | 0:40a613e7ba83 | 138 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 139 | * FUNCTION: write_bit |
| jeremycevrero | 0:40a613e7ba83 | 140 | * PURPOSE: Writes a single bit to the DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 141 | * |
| jeremycevrero | 0:40a613e7ba83 | 142 | * INPUT: bBit value of bit to be written |
| jeremycevrero | 0:40a613e7ba83 | 143 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 144 | * RETURN: - |
| jeremycevrero | 0:40a613e7ba83 | 145 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 146 | void write_bit(bool bBit) |
| jeremycevrero | 0:40a613e7ba83 | 147 | { |
| jeremycevrero | 0:40a613e7ba83 | 148 | DQ.output(); |
| jeremycevrero | 0:40a613e7ba83 | 149 | DQ=0; |
| jeremycevrero | 0:40a613e7ba83 | 150 | wait_us(DS1820_MSTR_BITSTART); |
| jeremycevrero | 0:40a613e7ba83 | 151 | |
| jeremycevrero | 0:40a613e7ba83 | 152 | if (bBit != false) DQ=1; |
| jeremycevrero | 0:40a613e7ba83 | 153 | |
| jeremycevrero | 0:40a613e7ba83 | 154 | wait_us(DS1820_BITWRITE_DLY); |
| jeremycevrero | 0:40a613e7ba83 | 155 | DQ=1; |
| jeremycevrero | 0:40a613e7ba83 | 156 | |
| jeremycevrero | 0:40a613e7ba83 | 157 | } |
| jeremycevrero | 0:40a613e7ba83 | 158 | |
| jeremycevrero | 0:40a613e7ba83 | 159 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 160 | * FUNCTION: read_byte |
| jeremycevrero | 0:40a613e7ba83 | 161 | * PURPOSE: Reads a single byte from the DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 162 | * |
| jeremycevrero | 0:40a613e7ba83 | 163 | * INPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 164 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 165 | * RETURN: uint8 byte which has been read from the DS1820 |
| jeremycevrero | 0:40a613e7ba83 | 166 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 167 | char read_byte(void) |
| jeremycevrero | 0:40a613e7ba83 | 168 | { |
| jeremycevrero | 0:40a613e7ba83 | 169 | char i; |
| jeremycevrero | 0:40a613e7ba83 | 170 | char value = 0; |
| jeremycevrero | 0:40a613e7ba83 | 171 | |
| jeremycevrero | 0:40a613e7ba83 | 172 | for (i=0 ; i < 8; i++) |
| jeremycevrero | 0:40a613e7ba83 | 173 | { |
| jeremycevrero | 0:40a613e7ba83 | 174 | if ( read_bit() ) value |= (1 << i); |
| jeremycevrero | 0:40a613e7ba83 | 175 | wait_us(120); |
| jeremycevrero | 0:40a613e7ba83 | 176 | } |
| jeremycevrero | 0:40a613e7ba83 | 177 | return(value); |
| jeremycevrero | 0:40a613e7ba83 | 178 | } |
| jeremycevrero | 0:40a613e7ba83 | 179 | |
| jeremycevrero | 0:40a613e7ba83 | 180 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 181 | * FUNCTION: write_byte |
| jeremycevrero | 0:40a613e7ba83 | 182 | * PURPOSE: Writes a single byte to the DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 183 | * |
| jeremycevrero | 0:40a613e7ba83 | 184 | * INPUT: val_u8 byte to be written |
| jeremycevrero | 0:40a613e7ba83 | 185 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 186 | * RETURN: - |
| jeremycevrero | 0:40a613e7ba83 | 187 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 188 | void write_byte(char val_u8) |
| jeremycevrero | 0:40a613e7ba83 | 189 | { |
| jeremycevrero | 0:40a613e7ba83 | 190 | char i; |
| jeremycevrero | 0:40a613e7ba83 | 191 | char temp; |
| jeremycevrero | 0:40a613e7ba83 | 192 | |
| jeremycevrero | 0:40a613e7ba83 | 193 | for (i=0; i < 8; i++) /* writes byte, one bit at a time */ |
| jeremycevrero | 0:40a613e7ba83 | 194 | { |
| jeremycevrero | 0:40a613e7ba83 | 195 | temp = val_u8 >> i; /* shifts val right 'i' spaces */ |
| jeremycevrero | 0:40a613e7ba83 | 196 | temp &= 0x01; /* copy that bit to temp */ |
| jeremycevrero | 0:40a613e7ba83 | 197 | write_bit(temp); /* write bit in temp into */ |
| jeremycevrero | 0:40a613e7ba83 | 198 | } |
| jeremycevrero | 0:40a613e7ba83 | 199 | |
| jeremycevrero | 0:40a613e7ba83 | 200 | wait_us(105); |
| jeremycevrero | 0:40a613e7ba83 | 201 | } |
| jeremycevrero | 0:40a613e7ba83 | 202 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 203 | // One wire crc |
| jeremycevrero | 0:40a613e7ba83 | 204 | char ow_crc(char x) |
| jeremycevrero | 0:40a613e7ba83 | 205 | { |
| jeremycevrero | 0:40a613e7ba83 | 206 | dowcrc = dscrc_table[dowcrc^x]; |
| jeremycevrero | 0:40a613e7ba83 | 207 | return dowcrc; |
| jeremycevrero | 0:40a613e7ba83 | 208 | } |
| jeremycevrero | 0:40a613e7ba83 | 209 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 210 | /* API Interface */ |
| jeremycevrero | 0:40a613e7ba83 | 211 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 212 | |
| jeremycevrero | 0:40a613e7ba83 | 213 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 214 | * FUNCTION: DS1820_AddrDevice |
| jeremycevrero | 0:40a613e7ba83 | 215 | * PURPOSE: Addresses a single or all devices on the 1-wire bus. |
| jeremycevrero | 0:40a613e7ba83 | 216 | * |
| jeremycevrero | 0:40a613e7ba83 | 217 | * INPUT: nAddrMethod use DS1820_CMD_MATCHROM to select a single |
| jeremycevrero | 0:40a613e7ba83 | 218 | * device or DS1820_CMD_SKIPROM to select all |
| jeremycevrero | 0:40a613e7ba83 | 219 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 220 | * RETURN: - |
| jeremycevrero | 0:40a613e7ba83 | 221 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 222 | void DS1820_AddrDevice(char nAddrMethod) |
| jeremycevrero | 0:40a613e7ba83 | 223 | { |
| jeremycevrero | 0:40a613e7ba83 | 224 | char i; |
| jeremycevrero | 0:40a613e7ba83 | 225 | |
| jeremycevrero | 0:40a613e7ba83 | 226 | if (nAddrMethod == DS1820_CMD_MATCHROM) |
| jeremycevrero | 0:40a613e7ba83 | 227 | { |
| jeremycevrero | 0:40a613e7ba83 | 228 | write_byte(DS1820_CMD_MATCHROM); /* address single devices on bus */ |
| jeremycevrero | 0:40a613e7ba83 | 229 | for (i = 0; i < DS1820_ADDR_LEN; i ++) |
| jeremycevrero | 0:40a613e7ba83 | 230 | write_byte(RomBytes[i]); |
| jeremycevrero | 0:40a613e7ba83 | 231 | } |
| jeremycevrero | 0:40a613e7ba83 | 232 | else |
| jeremycevrero | 0:40a613e7ba83 | 233 | write_byte(DS1820_CMD_SKIPROM); /* address all devices on bus */ |
| jeremycevrero | 0:40a613e7ba83 | 234 | } |
| jeremycevrero | 0:40a613e7ba83 | 235 | |
| jeremycevrero | 0:40a613e7ba83 | 236 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 237 | * FUNCTION: Next |
| jeremycevrero | 0:40a613e7ba83 | 238 | * PURPOSE: Finds next device connected to the 1-wire bus. |
| jeremycevrero | 0:40a613e7ba83 | 239 | * |
| jeremycevrero | 0:40a613e7ba83 | 240 | * INPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 241 | * OUTPUT: RomBytes[] ROM code of the next device |
| jeremycevrero | 0:40a613e7ba83 | 242 | * RETURN: bool TRUE if there are more devices on the 1-wire |
| jeremycevrero | 0:40a613e7ba83 | 243 | * bus, FALSE otherwise |
| jeremycevrero | 0:40a613e7ba83 | 244 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 245 | bool Next(void) |
| jeremycevrero | 0:40a613e7ba83 | 246 | { |
| jeremycevrero | 0:40a613e7ba83 | 247 | char x; |
| jeremycevrero | 0:40a613e7ba83 | 248 | char n; |
| jeremycevrero | 0:40a613e7ba83 | 249 | char k = 1; |
| jeremycevrero | 0:40a613e7ba83 | 250 | char m = 1; |
| jeremycevrero | 0:40a613e7ba83 | 251 | char discrepMarker = 0; |
| jeremycevrero | 0:40a613e7ba83 | 252 | bool g; |
| jeremycevrero | 0:40a613e7ba83 | 253 | bool flag; |
| jeremycevrero | 0:40a613e7ba83 | 254 | bool nxt = false; |
| jeremycevrero | 0:40a613e7ba83 | 255 | |
| jeremycevrero | 0:40a613e7ba83 | 256 | /* init ROM address */ |
| jeremycevrero | 0:40a613e7ba83 | 257 | for (n=0; n < 8; n ++) |
| jeremycevrero | 0:40a613e7ba83 | 258 | RomBytes[n] = 0x00; |
| jeremycevrero | 0:40a613e7ba83 | 259 | |
| jeremycevrero | 0:40a613e7ba83 | 260 | flag = ow_reset(); /* reset the 1-wire */ |
| jeremycevrero | 0:40a613e7ba83 | 261 | |
| jeremycevrero | 0:40a613e7ba83 | 262 | if (flag || doneFlag) /* no device found */ |
| jeremycevrero | 0:40a613e7ba83 | 263 | { |
| jeremycevrero | 0:40a613e7ba83 | 264 | lastDiscrep = 0; /* reset the search */ |
| jeremycevrero | 0:40a613e7ba83 | 265 | return false; |
| jeremycevrero | 0:40a613e7ba83 | 266 | } |
| jeremycevrero | 0:40a613e7ba83 | 267 | |
| jeremycevrero | 0:40a613e7ba83 | 268 | /* send search rom command */ |
| jeremycevrero | 0:40a613e7ba83 | 269 | write_byte(DS1820_CMD_SEARCHROM); |
| jeremycevrero | 0:40a613e7ba83 | 270 | |
| jeremycevrero | 0:40a613e7ba83 | 271 | n = 0; |
| jeremycevrero | 0:40a613e7ba83 | 272 | do |
| jeremycevrero | 0:40a613e7ba83 | 273 | { |
| jeremycevrero | 0:40a613e7ba83 | 274 | x = 0; |
| jeremycevrero | 0:40a613e7ba83 | 275 | |
| jeremycevrero | 0:40a613e7ba83 | 276 | /* read bit */ |
| jeremycevrero | 0:40a613e7ba83 | 277 | if ( read_bit() == 1 ) x = 2; |
| jeremycevrero | 0:40a613e7ba83 | 278 | wait_us(120); |
| jeremycevrero | 0:40a613e7ba83 | 279 | |
| jeremycevrero | 0:40a613e7ba83 | 280 | /* read bit complement */ |
| jeremycevrero | 0:40a613e7ba83 | 281 | if ( read_bit() == 1 ) x |= 1; |
| jeremycevrero | 0:40a613e7ba83 | 282 | wait_us(120); |
| jeremycevrero | 0:40a613e7ba83 | 283 | |
| jeremycevrero | 0:40a613e7ba83 | 284 | /* description for values of x: */ |
| jeremycevrero | 0:40a613e7ba83 | 285 | /* 00 There are devices connected to the bus which have conflicting */ |
| jeremycevrero | 0:40a613e7ba83 | 286 | /* bits in the current ROM code bit position. */ |
| jeremycevrero | 0:40a613e7ba83 | 287 | /* 01 All devices connected to the bus have a 0 in this bit position. */ |
| jeremycevrero | 0:40a613e7ba83 | 288 | /* 10 All devices connected to the bus have a 1 in this bit position. */ |
| jeremycevrero | 0:40a613e7ba83 | 289 | /* 11 There are no devices connected to the 1-wire bus. */ |
| jeremycevrero | 0:40a613e7ba83 | 290 | |
| jeremycevrero | 0:40a613e7ba83 | 291 | /* if there are no devices on the bus */ |
| jeremycevrero | 0:40a613e7ba83 | 292 | if (x == 3) break; |
| jeremycevrero | 0:40a613e7ba83 | 293 | else |
| jeremycevrero | 0:40a613e7ba83 | 294 | { |
| jeremycevrero | 0:40a613e7ba83 | 295 | /* devices have the same logical value at this position */ |
| jeremycevrero | 0:40a613e7ba83 | 296 | if (x > 0) g = (bool)(x >> 1);// get bit value |
| jeremycevrero | 0:40a613e7ba83 | 297 | /* devices have confilcting bits in the current ROM code */ |
| jeremycevrero | 0:40a613e7ba83 | 298 | else |
| jeremycevrero | 0:40a613e7ba83 | 299 | { |
| jeremycevrero | 0:40a613e7ba83 | 300 | /* if there was a conflict on the last iteration */ |
| jeremycevrero | 0:40a613e7ba83 | 301 | if (m < lastDiscrep) |
| jeremycevrero | 0:40a613e7ba83 | 302 | /* take same bit as in last iteration */ |
| jeremycevrero | 0:40a613e7ba83 | 303 | g = ( (RomBytes[n] & k) > 0 ); |
| jeremycevrero | 0:40a613e7ba83 | 304 | else |
| jeremycevrero | 0:40a613e7ba83 | 305 | g = (m == lastDiscrep); |
| jeremycevrero | 0:40a613e7ba83 | 306 | |
| jeremycevrero | 0:40a613e7ba83 | 307 | if (g == 0) |
| jeremycevrero | 0:40a613e7ba83 | 308 | discrepMarker = m; |
| jeremycevrero | 0:40a613e7ba83 | 309 | } |
| jeremycevrero | 0:40a613e7ba83 | 310 | |
| jeremycevrero | 0:40a613e7ba83 | 311 | /* store bit in ROM address */ |
| jeremycevrero | 0:40a613e7ba83 | 312 | if (g ==1) |
| jeremycevrero | 0:40a613e7ba83 | 313 | RomBytes[n] |= k; |
| jeremycevrero | 0:40a613e7ba83 | 314 | else |
| jeremycevrero | 0:40a613e7ba83 | 315 | RomBytes[n] &= ~k; |
| jeremycevrero | 0:40a613e7ba83 | 316 | |
| jeremycevrero | 0:40a613e7ba83 | 317 | write_bit(g); |
| jeremycevrero | 0:40a613e7ba83 | 318 | |
| jeremycevrero | 0:40a613e7ba83 | 319 | /* increment bit position */ |
| jeremycevrero | 0:40a613e7ba83 | 320 | m ++; |
| jeremycevrero | 0:40a613e7ba83 | 321 | |
| jeremycevrero | 0:40a613e7ba83 | 322 | /* calculate next mask value */ |
| jeremycevrero | 0:40a613e7ba83 | 323 | k = k << 1; |
| jeremycevrero | 0:40a613e7ba83 | 324 | |
| jeremycevrero | 0:40a613e7ba83 | 325 | /* check if this byte has finished */ |
| jeremycevrero | 0:40a613e7ba83 | 326 | if (k == 0) |
| jeremycevrero | 0:40a613e7ba83 | 327 | { |
| jeremycevrero | 0:40a613e7ba83 | 328 | ow_crc(RomBytes[n]); // Accumulate the crc |
| jeremycevrero | 0:40a613e7ba83 | 329 | n ++; /* advance to next byte of ROM mask */ |
| jeremycevrero | 0:40a613e7ba83 | 330 | k = 1; /* update mask */ |
| jeremycevrero | 0:40a613e7ba83 | 331 | } |
| jeremycevrero | 0:40a613e7ba83 | 332 | } |
| jeremycevrero | 0:40a613e7ba83 | 333 | } while (n < DS1820_ADDR_LEN); |
| jeremycevrero | 0:40a613e7ba83 | 334 | |
| jeremycevrero | 0:40a613e7ba83 | 335 | |
| jeremycevrero | 0:40a613e7ba83 | 336 | /* if search was unsuccessful then */ |
| jeremycevrero | 0:40a613e7ba83 | 337 | if ((m < 65) ||dowcrc) |
| jeremycevrero | 0:40a613e7ba83 | 338 | // if (m < 65 ) |
| jeremycevrero | 0:40a613e7ba83 | 339 | /* reset the last discrepancy to 0 */ |
| jeremycevrero | 0:40a613e7ba83 | 340 | lastDiscrep = 0; |
| jeremycevrero | 0:40a613e7ba83 | 341 | else |
| jeremycevrero | 0:40a613e7ba83 | 342 | { |
| jeremycevrero | 0:40a613e7ba83 | 343 | /* search was successful */ |
| jeremycevrero | 0:40a613e7ba83 | 344 | lastDiscrep = discrepMarker; |
| jeremycevrero | 0:40a613e7ba83 | 345 | doneFlag = (lastDiscrep == 0); |
| jeremycevrero | 0:40a613e7ba83 | 346 | |
| jeremycevrero | 0:40a613e7ba83 | 347 | /* indicates search is not complete yet, more parts remain */ |
| jeremycevrero | 0:40a613e7ba83 | 348 | nxt = true; |
| jeremycevrero | 0:40a613e7ba83 | 349 | } |
| jeremycevrero | 0:40a613e7ba83 | 350 | return nxt; |
| jeremycevrero | 0:40a613e7ba83 | 351 | } |
| jeremycevrero | 0:40a613e7ba83 | 352 | |
| jeremycevrero | 0:40a613e7ba83 | 353 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 354 | * FUNCTION: First |
| jeremycevrero | 0:40a613e7ba83 | 355 | * PURPOSE: Starts the device search on the 1-wire bus. |
| jeremycevrero | 0:40a613e7ba83 | 356 | * |
| jeremycevrero | 0:40a613e7ba83 | 357 | * INPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 358 | * OUTPUT: RomBytes[] ROM code of the first device |
| jeremycevrero | 0:40a613e7ba83 | 359 | * RETURN: bool TRUE if there are more devices on the 1-wire |
| jeremycevrero | 0:40a613e7ba83 | 360 | * bus, FALSE otherwise |
| jeremycevrero | 0:40a613e7ba83 | 361 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 362 | bool First(void) |
| jeremycevrero | 0:40a613e7ba83 | 363 | { |
| jeremycevrero | 0:40a613e7ba83 | 364 | lastDiscrep = 0; |
| jeremycevrero | 0:40a613e7ba83 | 365 | doneFlag = false; |
| jeremycevrero | 0:40a613e7ba83 | 366 | |
| jeremycevrero | 0:40a613e7ba83 | 367 | return ( Next() ); |
| jeremycevrero | 0:40a613e7ba83 | 368 | } |
| jeremycevrero | 0:40a613e7ba83 | 369 | /* -------------------------------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 370 | void FindDevices(void) |
| jeremycevrero | 0:40a613e7ba83 | 371 | { |
| jeremycevrero | 0:40a613e7ba83 | 372 | char m; |
| jeremycevrero | 0:40a613e7ba83 | 373 | if(!ow_reset()) |
| jeremycevrero | 0:40a613e7ba83 | 374 | { |
| jeremycevrero | 0:40a613e7ba83 | 375 | if(First()) // Begins when at least one part found |
| jeremycevrero | 0:40a613e7ba83 | 376 | { |
| jeremycevrero | 0:40a613e7ba83 | 377 | numROMs = 0; |
| jeremycevrero | 0:40a613e7ba83 | 378 | do |
| jeremycevrero | 0:40a613e7ba83 | 379 | { |
| jeremycevrero | 0:40a613e7ba83 | 380 | numROMs++; |
| jeremycevrero | 0:40a613e7ba83 | 381 | for (m=0;m<8;m++) |
| jeremycevrero | 0:40a613e7ba83 | 382 | { |
| jeremycevrero | 0:40a613e7ba83 | 383 | FoundROM[numROMs-1][m] = RomBytes[m]; |
| jeremycevrero | 0:40a613e7ba83 | 384 | } |
| jeremycevrero | 0:40a613e7ba83 | 385 | } while (Next()&&(numROMs<10)); // Continues until no additional |
| jeremycevrero | 0:40a613e7ba83 | 386 | } |
| jeremycevrero | 0:40a613e7ba83 | 387 | } |
| jeremycevrero | 0:40a613e7ba83 | 388 | |
| jeremycevrero | 0:40a613e7ba83 | 389 | } |
| jeremycevrero | 0:40a613e7ba83 | 390 | //****************************************************************************** |
| jeremycevrero | 0:40a613e7ba83 | 391 | // Sends Match ROM command to bus then device address |
| jeremycevrero | 0:40a613e7ba83 | 392 | char Send_MatchRom(char actNumROM) |
| jeremycevrero | 0:40a613e7ba83 | 393 | { |
| jeremycevrero | 0:40a613e7ba83 | 394 | char i; |
| jeremycevrero | 0:40a613e7ba83 | 395 | if (ow_reset()) return false; // 0 if device present |
| jeremycevrero | 0:40a613e7ba83 | 396 | write_byte(0x55); // Match ROM |
| jeremycevrero | 0:40a613e7ba83 | 397 | |
| jeremycevrero | 0:40a613e7ba83 | 398 | for (i=0;i<8;i++) |
| jeremycevrero | 0:40a613e7ba83 | 399 | { |
| jeremycevrero | 0:40a613e7ba83 | 400 | write_byte(FoundROM[actNumROM][i]); // Send ROM code |
| jeremycevrero | 0:40a613e7ba83 | 401 | } |
| jeremycevrero | 0:40a613e7ba83 | 402 | |
| jeremycevrero | 0:40a613e7ba83 | 403 | return true; |
| jeremycevrero | 0:40a613e7ba83 | 404 | } |
| jeremycevrero | 0:40a613e7ba83 | 405 | //****************************************************************************** |
| jeremycevrero | 0:40a613e7ba83 | 406 | void Read_ROMCode(void) |
| jeremycevrero | 0:40a613e7ba83 | 407 | { |
| jeremycevrero | 0:40a613e7ba83 | 408 | char n; |
| jeremycevrero | 0:40a613e7ba83 | 409 | char dat[9]; |
| jeremycevrero | 0:40a613e7ba83 | 410 | |
| jeremycevrero | 0:40a613e7ba83 | 411 | ow_reset(); |
| jeremycevrero | 0:40a613e7ba83 | 412 | write_byte(0x33); |
| jeremycevrero | 0:40a613e7ba83 | 413 | for (n=0;n<8;n++){dat[n]=read_byte();} |
| jeremycevrero | 0:40a613e7ba83 | 414 | |
| jeremycevrero | 0:40a613e7ba83 | 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], |
| jeremycevrero | 0:40a613e7ba83 | 416 | dat[6],dat[7]); |
| jeremycevrero | 0:40a613e7ba83 | 417 | |
| jeremycevrero | 0:40a613e7ba83 | 418 | wait_ms(5000); |
| jeremycevrero | 0:40a613e7ba83 | 419 | } |
| jeremycevrero | 0:40a613e7ba83 | 420 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 421 | * FUNCTION: DS1820_WriteEEPROM |
| jeremycevrero | 0:40a613e7ba83 | 422 | * PURPOSE: Writes to the DS1820 EEPROM memory (2 bytes available). |
| jeremycevrero | 0:40a613e7ba83 | 423 | * |
| jeremycevrero | 0:40a613e7ba83 | 424 | * INPUT: nTHigh high byte of EEPROM |
| jeremycevrero | 0:40a613e7ba83 | 425 | * nTLow low byte of EEPROM |
| jeremycevrero | 0:40a613e7ba83 | 426 | * OUTPUT: - |
| jeremycevrero | 0:40a613e7ba83 | 427 | * RETURN: - |
| jeremycevrero | 0:40a613e7ba83 | 428 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 429 | void DS1820_WriteEEPROM(char nTHigh, char nTLow) |
| jeremycevrero | 0:40a613e7ba83 | 430 | { |
| jeremycevrero | 0:40a613e7ba83 | 431 | /* --- write to scratchpad ----------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 432 | ow_reset(); // appel de la fonction ow_reset |
| jeremycevrero | 0:40a613e7ba83 | 433 | DS1820_AddrDevice(DS1820_CMD_MATCHROM); |
| jeremycevrero | 0:40a613e7ba83 | 434 | write_byte(DS1820_CMD_WRITESCRPAD); // debut conversion |
| jeremycevrero | 0:40a613e7ba83 | 435 | write_byte(nTHigh); |
| jeremycevrero | 0:40a613e7ba83 | 436 | write_byte(nTLow); |
| jeremycevrero | 0:40a613e7ba83 | 437 | wait_us(10); // attendre 10ms |
| jeremycevrero | 0:40a613e7ba83 | 438 | ow_reset(); // appel de la fonction ow_reset |
| jeremycevrero | 0:40a613e7ba83 | 439 | DS1820_AddrDevice(DS1820_CMD_MATCHROM); |
| jeremycevrero | 0:40a613e7ba83 | 440 | write_byte(DS1820_CMD_COPYSCRPAD); // start conversion |
| jeremycevrero | 0:40a613e7ba83 | 441 | G__MOS_P=0; // "strong pullup" |
| jeremycevrero | 0:40a613e7ba83 | 442 | wait_ms(10); // attendre 10 ms |
| jeremycevrero | 0:40a613e7ba83 | 443 | G__MOS_P=1; // "strong pullup" |
| jeremycevrero | 0:40a613e7ba83 | 444 | } |
| jeremycevrero | 0:40a613e7ba83 | 445 | |
| jeremycevrero | 0:40a613e7ba83 | 446 | /******************************************************************************* |
| jeremycevrero | 0:40a613e7ba83 | 447 | * FUNCTION: DS1820_GetTemp |
| jeremycevrero | 0:40a613e7ba83 | 448 | * PURPOSE: Get temperature value from single DS1820 device. |
| jeremycevrero | 0:40a613e7ba83 | 449 | * |
| jeremycevrero | 0:40a613e7ba83 | 450 | * Scratchpad Memory Layout |
| jeremycevrero | 0:40a613e7ba83 | 451 | * Byte Register |
| jeremycevrero | 0:40a613e7ba83 | 452 | * 0 Temperature_LSB |
| jeremycevrero | 0:40a613e7ba83 | 453 | * 1 Temperature_MSB |
| jeremycevrero | 0:40a613e7ba83 | 454 | * 2 Temp Alarm High / User Byte 1 |
| jeremycevrero | 0:40a613e7ba83 | 455 | * 3 Temp Alarm Low / User Byte 2 |
| jeremycevrero | 0:40a613e7ba83 | 456 | * 4 Reserved |
| jeremycevrero | 0:40a613e7ba83 | 457 | * 5 Reserved |
| jeremycevrero | 0:40a613e7ba83 | 458 | * 6 Count_Remain |
| jeremycevrero | 0:40a613e7ba83 | 459 | * 7 Count_per_C |
| jeremycevrero | 0:40a613e7ba83 | 460 | * 8 CRC |
| jeremycevrero | 0:40a613e7ba83 | 461 | * |
| jeremycevrero | 0:40a613e7ba83 | 462 | * Temperature calculation for DS18S20 (Family Code 0x10): |
| jeremycevrero | 0:40a613e7ba83 | 463 | * ======================================================= |
| jeremycevrero | 0:40a613e7ba83 | 464 | * (Count_per_C - Count_Remain) |
| jeremycevrero | 0:40a613e7ba83 | 465 | * Temperature = temp_read - 0.25 + ---------------------------- |
| jeremycevrero | 0:40a613e7ba83 | 466 | * Count_per_C |
| jeremycevrero | 0:40a613e7ba83 | 467 | * |
| jeremycevrero | 0:40a613e7ba83 | 468 | * Where temp_read is the value from the temp_MSB and temp_LSB with |
| jeremycevrero | 0:40a613e7ba83 | 469 | * the least significant bit removed (the 0.5C bit). |
| jeremycevrero | 0:40a613e7ba83 | 470 | * |
| jeremycevrero | 0:40a613e7ba83 | 471 | * |
| jeremycevrero | 0:40a613e7ba83 | 472 | * Temperature calculation for DS18B20 (Family Code 0x28): |
| jeremycevrero | 0:40a613e7ba83 | 473 | * ======================================================= |
| jeremycevrero | 0:40a613e7ba83 | 474 | * bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 |
| jeremycevrero | 0:40a613e7ba83 | 475 | * LSB 2^3 2^2 2^1 2^0 2^-1 2^-2 2^-3 2^-4 |
| jeremycevrero | 0:40a613e7ba83 | 476 | * bit15 bit14 bit13 bit12 bit3 bit2 bit1 bit0 |
| jeremycevrero | 0:40a613e7ba83 | 477 | * MSB S S S S S 2^6 2^5 2^4 |
| jeremycevrero | 0:40a613e7ba83 | 478 | * |
| jeremycevrero | 0:40a613e7ba83 | 479 | * The temperature data is stored as a 16-bit sign-extended two�s |
| jeremycevrero | 0:40a613e7ba83 | 480 | * complement number in the temperature register. The sign bits (S) |
| jeremycevrero | 0:40a613e7ba83 | 481 | * indicate if the temperature is positive or negative: for |
| jeremycevrero | 0:40a613e7ba83 | 482 | * positive numbers S = 0 and for negative numbers S = 1. |
| jeremycevrero | 0:40a613e7ba83 | 483 | * |
| jeremycevrero | 0:40a613e7ba83 | 484 | * RETURN: float |
| jeremycevrero | 0:40a613e7ba83 | 485 | ******************************************************************************/ |
| jeremycevrero | 0:40a613e7ba83 | 486 | float DS1820_GetTemp(void) //fonction capture de la temperature |
| jeremycevrero | 0:40a613e7ba83 | 487 | { |
| jeremycevrero | 0:40a613e7ba83 | 488 | char i; //declaration de la variable i |
| jeremycevrero | 0:40a613e7ba83 | 489 | char scrpad[DS1820_SCRPADMEM_LEN]; //declaration de la variable scrpad[DS1820_SCRPADMEM_LEN] |
| jeremycevrero | 0:40a613e7ba83 | 490 | signed char temp_read; //declaration de la variable signe temp_read |
| jeremycevrero | 0:40a613e7ba83 | 491 | float temperature; //declaration de la variable flotante temperature |
| jeremycevrero | 0:40a613e7ba83 | 492 | |
| jeremycevrero | 0:40a613e7ba83 | 493 | /* --- start temperature conversion -------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 494 | ow_reset(); |
| jeremycevrero | 0:40a613e7ba83 | 495 | DS1820_AddrDevice(DS1820_CMD_MATCHROM); /* address the device */ |
| jeremycevrero | 0:40a613e7ba83 | 496 | DQ.output(); //DQ en sortie |
| jeremycevrero | 0:40a613e7ba83 | 497 | DQ=1; //DQ � 1 |
| jeremycevrero | 0:40a613e7ba83 | 498 | write_byte(DS1820_CMD_CONVERTTEMP); /* start conversion */ |
| jeremycevrero | 0:40a613e7ba83 | 499 | G__MOS_P=0; //"strong pullup" |
| jeremycevrero | 0:40a613e7ba83 | 500 | /* wait for temperature conversion */ |
| jeremycevrero | 0:40a613e7ba83 | 501 | wait_ms(750); // attendre 0.75s |
| jeremycevrero | 0:40a613e7ba83 | 502 | G__MOS_P=1; //"strong pullup" |
| jeremycevrero | 0:40a613e7ba83 | 503 | |
| jeremycevrero | 0:40a613e7ba83 | 504 | /* --- read sratchpad ---------------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 505 | ow_reset(); |
| jeremycevrero | 0:40a613e7ba83 | 506 | DS1820_AddrDevice(DS1820_CMD_MATCHROM); /* address the device */ |
| jeremycevrero | 0:40a613e7ba83 | 507 | write_byte(DS1820_CMD_READSCRPAD); /* read scratch pad */ |
| jeremycevrero | 0:40a613e7ba83 | 508 | |
| jeremycevrero | 0:40a613e7ba83 | 509 | /* read scratch pad data */ |
| jeremycevrero | 0:40a613e7ba83 | 510 | for (i=0; i < DS1820_SCRPADMEM_LEN; i++) // boucle for : i=0 puis on l'incremante jusqu'a i < DS1820_SCRPADMEM_LEN |
| jeremycevrero | 0:40a613e7ba83 | 511 | scrpad[i] = read_byte(); |
| jeremycevrero | 0:40a613e7ba83 | 512 | |
| jeremycevrero | 0:40a613e7ba83 | 513 | /* --- calculate temperature --------------------------------------------- */ |
| jeremycevrero | 0:40a613e7ba83 | 514 | |
| jeremycevrero | 0:40a613e7ba83 | 515 | if (RomBytes[0] == DS1820_FAMILY_CODE_DS18S20) |
| jeremycevrero | 0:40a613e7ba83 | 516 | { |
| jeremycevrero | 0:40a613e7ba83 | 517 | /////////////////////// precision O,5 degC ////////////////////////////////////// |
| jeremycevrero | 0:40a613e7ba83 | 518 | /*// temp = (signed int) make16(scrpad[1],scrpad[0]); |
| jeremycevrero | 0:40a613e7ba83 | 519 | temp = (signed int) ((int)scrpad[1]<<8 | (int)scrpad[0]); |
| jeremycevrero | 0:40a613e7ba83 | 520 | temperature =(float)temp/2;*/ |
| jeremycevrero | 0:40a613e7ba83 | 521 | ///////////////////////////////////////////////////////////////////////////////// |
| jeremycevrero | 0:40a613e7ba83 | 522 | |
| jeremycevrero | 0:40a613e7ba83 | 523 | ////////////////////// precision O,1 deg //////////////////////////////////////// |
| jeremycevrero | 0:40a613e7ba83 | 524 | //...calcul.... |
| jeremycevrero | 0:40a613e7ba83 | 525 | temp_read=(signed char)(((int)scrpad[1]<<8 | (int)scrpad[0])>>1); |
| jeremycevrero | 0:40a613e7ba83 | 526 | temperature=(float)(temp_read); |
| jeremycevrero | 0:40a613e7ba83 | 527 | temperature = temperature + 0.75 - (float)(scrpad[6]/(float)scrpad[7]); |
| jeremycevrero | 0:40a613e7ba83 | 528 | //////////////////////////////////////////////////////////////////////////////// |
| jeremycevrero | 0:40a613e7ba83 | 529 | } |
| jeremycevrero | 0:40a613e7ba83 | 530 | else//ds18b20 |
| jeremycevrero | 0:40a613e7ba83 | 531 | temperature =((float) (signed int)((int)scrpad[1]<<8 | (int)scrpad[0]))/16; |
| jeremycevrero | 0:40a613e7ba83 | 532 | |
| jeremycevrero | 0:40a613e7ba83 | 533 | return (temperature); |
| jeremycevrero | 0:40a613e7ba83 | 534 | } |
| jeremycevrero | 0:40a613e7ba83 | 535 | //****************************************************************************** |
| jeremycevrero | 0:40a613e7ba83 | 536 | void read_temp() |
| jeremycevrero | 0:40a613e7ba83 | 537 | { |
| jeremycevrero | 0:40a613e7ba83 | 538 | G__MOS_P =1 ; /* initialisation du P-MOS */ |
| jeremycevrero | 0:40a613e7ba83 | 539 | FindDevices(); /* fonction cherchant le nombre de ds1820 |
| jeremycevrero | 0:40a613e7ba83 | 540 | et leur numero de serie */ |
| jeremycevrero | 0:40a613e7ba83 | 541 | if ( First() ) /* fonction if */ |
| jeremycevrero | 0:40a613e7ba83 | 542 | { |
| jeremycevrero | 0:40a613e7ba83 | 543 | temperature = DS1820_GetTemp(); /* affectation du resultat de la temperature |
| jeremycevrero | 0:40a613e7ba83 | 544 | a la variable temperature */ |
| jeremycevrero | 0:40a613e7ba83 | 545 | pc.printf("\t temp = % +.3g""\xb0""C \r",temperature); /* affichage de la temperature */ |
| jeremycevrero | 0:40a613e7ba83 | 546 | } |
| jeremycevrero | 0:40a613e7ba83 | 547 | |
| jeremycevrero | 0:40a613e7ba83 | 548 | } |