Maxim Integrated / OneWire

1-Wire® library for mbed. Complete 1-Wire library that supports our silicon masters along with a bit-bang master on the MAX32600MBED platform with one common interface for mbed. Slave support has also been included and more slaves will be added as time permits.

Dependents:   MAXREFDES131_Qt_Demo MAX32630FTHR_iButton_uSD_Logger MAX32630FTHR_DS18B20_uSD_Logger MAXREFDES130_131_Demo ... more

Superseded by MaximInterface.

Masters/OneWireMaster.cpp@78:0cbbac7f2016, 2016-05-16 (annotated)

Committer:
IanBenzMaxim
Date:
Mon May 16 15:18:09 2016 -0500
Revision:
78:0cbbac7f2016
Parent:
77:529edb329ee0
Child:
82:c11090a32471
Code cleanup.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
j3 5:ce108eeb878d 1 /******************************************************************//**
j3 5:ce108eeb878d 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
j3 5:ce108eeb878d 3 *
j3 5:ce108eeb878d 4 * Permission is hereby granted, free of charge, to any person obtaining a
j3 5:ce108eeb878d 5 * copy of this software and associated documentation files (the "Software"),
j3 5:ce108eeb878d 6 * to deal in the Software without restriction, including without limitation
j3 5:ce108eeb878d 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
j3 5:ce108eeb878d 8 * and/or sell copies of the Software, and to permit persons to whom the
j3 5:ce108eeb878d 9 * Software is furnished to do so, subject to the following conditions:
j3 5:ce108eeb878d 10 *
j3 5:ce108eeb878d 11 * The above copyright notice and this permission notice shall be included
j3 5:ce108eeb878d 12 * in all copies or substantial portions of the Software.
j3 5:ce108eeb878d 13 *
j3 5:ce108eeb878d 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
j3 5:ce108eeb878d 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
j3 5:ce108eeb878d 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
j3 5:ce108eeb878d 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
j3 5:ce108eeb878d 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
j3 5:ce108eeb878d 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
j3 5:ce108eeb878d 20 * OTHER DEALINGS IN THE SOFTWARE.
j3 5:ce108eeb878d 21 *
j3 5:ce108eeb878d 22 * Except as contained in this notice, the name of Maxim Integrated
j3 5:ce108eeb878d 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
j3 5:ce108eeb878d 24 * Products, Inc. Branding Policy.
j3 5:ce108eeb878d 25 *
j3 5:ce108eeb878d 26 * The mere transfer of this software does not imply any licenses
j3 5:ce108eeb878d 27 * of trade secrets, proprietary technology, copyrights, patents,
j3 5:ce108eeb878d 28 * trademarks, maskwork rights, or any other form of intellectual
j3 5:ce108eeb878d 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
j3 5:ce108eeb878d 30 * ownership rights.
j3 5:ce108eeb878d 31 **********************************************************************/
j3 5:ce108eeb878d 32
j3 15:f6cb0d906fb6 33 #include "OneWireMaster.h"
IanBenzMaxim 73:2cecc1372acc 34 #include "RomId.h"
IanBenzMaxim 27:d5aaefa252f1 35
IanBenzMaxim 76:84e6c4994e29 36 using OneWire::OneWireMaster;
j3 15:f6cb0d906fb6 37
IanBenzMaxim 77:529edb329ee0 38 enum OwRomCmd
IanBenzMaxim 77:529edb329ee0 39 {
IanBenzMaxim 77:529edb329ee0 40 ReadRomCmd = 0x33,
IanBenzMaxim 77:529edb329ee0 41 MatchRomCmd = 0x55,
IanBenzMaxim 77:529edb329ee0 42 SearchRomCmd = 0xF0,
IanBenzMaxim 77:529edb329ee0 43 SkipRomCmd = 0xCC,
IanBenzMaxim 77:529edb329ee0 44 ResumeCmd = 0xA5,
IanBenzMaxim 77:529edb329ee0 45 OverdriveSkipRomCmd = 0x3C,
IanBenzMaxim 77:529edb329ee0 46 OverdriveMatchRomCmd = 0x69
IanBenzMaxim 77:529edb329ee0 47 };
IanBenzMaxim 77:529edb329ee0 48
IanBenzMaxim 75:8b627804927c 49 OneWireMaster::CmdResult OneWireMaster::OWWriteBlock(const uint8_t *sendBuf, uint8_t sendLen)
IanBenzMaxim 71:562f5c702094 50 {
IanBenzMaxim 71:562f5c702094 51 CmdResult result;
IanBenzMaxim 74:23be10c32fa3 52
IanBenzMaxim 75:8b627804927c 53 for (uint8_t idx = 0; idx < sendLen; idx++)
IanBenzMaxim 71:562f5c702094 54 {
IanBenzMaxim 75:8b627804927c 55 result = OWWriteByte(sendBuf[idx]);
IanBenzMaxim 74:23be10c32fa3 56 if (result != Success)
IanBenzMaxim 71:562f5c702094 57 {
IanBenzMaxim 71:562f5c702094 58 break;
IanBenzMaxim 71:562f5c702094 59 }
IanBenzMaxim 71:562f5c702094 60 }
IanBenzMaxim 74:23be10c32fa3 61
IanBenzMaxim 71:562f5c702094 62 return result;
IanBenzMaxim 71:562f5c702094 63 }
IanBenzMaxim 71:562f5c702094 64
IanBenzMaxim 75:8b627804927c 65 OneWireMaster::CmdResult OneWireMaster::OWReadBlock(uint8_t *recvBuf, uint8_t recvLen)
IanBenzMaxim 71:562f5c702094 66 {
IanBenzMaxim 71:562f5c702094 67 CmdResult result;
IanBenzMaxim 74:23be10c32fa3 68
IanBenzMaxim 75:8b627804927c 69 for (uint8_t idx = 0; idx < recvLen; idx++)
IanBenzMaxim 71:562f5c702094 70 {
IanBenzMaxim 75:8b627804927c 71 result = OWReadByte(recvBuf[idx]);
IanBenzMaxim 74:23be10c32fa3 72 if (result != Success)
IanBenzMaxim 71:562f5c702094 73 {
IanBenzMaxim 71:562f5c702094 74 break;
IanBenzMaxim 71:562f5c702094 75 }
IanBenzMaxim 71:562f5c702094 76 }
IanBenzMaxim 74:23be10c32fa3 77
IanBenzMaxim 71:562f5c702094 78 return result;
IanBenzMaxim 71:562f5c702094 79 }
IanBenzMaxim 71:562f5c702094 80
IanBenzMaxim 75:8b627804927c 81 OneWireMaster::CmdResult OneWireMaster::OWTriplet(SearchDirection & searchDirection, uint8_t & sbr, uint8_t & tsb)
IanBenzMaxim 32:bce180b544ed 82 {
IanBenzMaxim 32:bce180b544ed 83 CmdResult result;
IanBenzMaxim 32:bce180b544ed 84 result = OWReadBit(sbr);
IanBenzMaxim 32:bce180b544ed 85 if (result == Success)
IanBenzMaxim 74:23be10c32fa3 86 {
IanBenzMaxim 32:bce180b544ed 87 result = OWReadBit(tsb);
IanBenzMaxim 74:23be10c32fa3 88 }
IanBenzMaxim 32:bce180b544ed 89 if (result == Success)
IanBenzMaxim 32:bce180b544ed 90 {
IanBenzMaxim 57:1635f247ceae 91 if (sbr)
IanBenzMaxim 74:23be10c32fa3 92 {
IanBenzMaxim 75:8b627804927c 93 searchDirection = WriteOne;
IanBenzMaxim 74:23be10c32fa3 94 }
IanBenzMaxim 57:1635f247ceae 95 else if (tsb)
IanBenzMaxim 74:23be10c32fa3 96 {
IanBenzMaxim 75:8b627804927c 97 searchDirection = WriteZero;
IanBenzMaxim 74:23be10c32fa3 98 }
IanBenzMaxim 32:bce180b544ed 99 // else: use search_direction parameter
IanBenzMaxim 74:23be10c32fa3 100
IanBenzMaxim 75:8b627804927c 101 result = OWWriteBit((searchDirection == WriteOne) ? 1 : 0);
IanBenzMaxim 32:bce180b544ed 102 }
IanBenzMaxim 32:bce180b544ed 103 return result;
IanBenzMaxim 32:bce180b544ed 104 }
IanBenzMaxim 32:bce180b544ed 105
IanBenzMaxim 77:529edb329ee0 106 void OneWireMaster::SearchState::reset()
IanBenzMaxim 77:529edb329ee0 107 {
IanBenzMaxim 77:529edb329ee0 108 last_discrepancy = 0;
IanBenzMaxim 77:529edb329ee0 109 last_device_flag = false;
IanBenzMaxim 77:529edb329ee0 110 last_family_discrepancy = 0;
IanBenzMaxim 77:529edb329ee0 111 romId.reset();
IanBenzMaxim 77:529edb329ee0 112 }
IanBenzMaxim 77:529edb329ee0 113
IanBenzMaxim 77:529edb329ee0 114 void OneWireMaster::SearchState::findFamily(uint8_t familyCode)
IanBenzMaxim 77:529edb329ee0 115 {
IanBenzMaxim 77:529edb329ee0 116 reset();
IanBenzMaxim 77:529edb329ee0 117 romId.setFamilyCode(familyCode);
IanBenzMaxim 77:529edb329ee0 118 last_discrepancy = 64;
IanBenzMaxim 77:529edb329ee0 119 }
IanBenzMaxim 77:529edb329ee0 120
IanBenzMaxim 77:529edb329ee0 121 void OneWireMaster::SearchState::skipCurrentFamily()
IanBenzMaxim 77:529edb329ee0 122 {
IanBenzMaxim 77:529edb329ee0 123 // set the Last discrepancy to last family discrepancy
IanBenzMaxim 77:529edb329ee0 124 last_discrepancy = last_family_discrepancy;
IanBenzMaxim 77:529edb329ee0 125
IanBenzMaxim 77:529edb329ee0 126 // clear the last family discrpepancy
IanBenzMaxim 77:529edb329ee0 127 last_family_discrepancy = 0;
IanBenzMaxim 77:529edb329ee0 128
IanBenzMaxim 77:529edb329ee0 129 // check for end of list
IanBenzMaxim 77:529edb329ee0 130 if (last_discrepancy == 0)
IanBenzMaxim 77:529edb329ee0 131 {
IanBenzMaxim 77:529edb329ee0 132 last_device_flag = true;
IanBenzMaxim 77:529edb329ee0 133 }
IanBenzMaxim 77:529edb329ee0 134 }
IanBenzMaxim 77:529edb329ee0 135
IanBenzMaxim 77:529edb329ee0 136 OneWireMaster::CmdResult OneWireMaster::OWFirst(SearchState & searchState)
IanBenzMaxim 77:529edb329ee0 137 {
IanBenzMaxim 77:529edb329ee0 138 // Reset and begin a new search
IanBenzMaxim 77:529edb329ee0 139 searchState.reset();
IanBenzMaxim 77:529edb329ee0 140 return OWSearch(searchState);
IanBenzMaxim 77:529edb329ee0 141 }
IanBenzMaxim 77:529edb329ee0 142
IanBenzMaxim 77:529edb329ee0 143 OneWireMaster::CmdResult OneWireMaster::OWNext(SearchState & searchState)
IanBenzMaxim 77:529edb329ee0 144 {
IanBenzMaxim 77:529edb329ee0 145 // Continue the previous search
IanBenzMaxim 77:529edb329ee0 146 return OWSearch(searchState);
IanBenzMaxim 77:529edb329ee0 147 }
IanBenzMaxim 77:529edb329ee0 148
IanBenzMaxim 77:529edb329ee0 149 OneWireMaster::CmdResult OneWireMaster::OWVerify(const RomId & romId)
IanBenzMaxim 77:529edb329ee0 150 {
IanBenzMaxim 77:529edb329ee0 151 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 152 SearchState searchState;
IanBenzMaxim 77:529edb329ee0 153
IanBenzMaxim 77:529edb329ee0 154 searchState.romId = romId;
IanBenzMaxim 77:529edb329ee0 155
IanBenzMaxim 77:529edb329ee0 156 // set search to find the same device
IanBenzMaxim 77:529edb329ee0 157 searchState.last_discrepancy = 64;
IanBenzMaxim 77:529edb329ee0 158 searchState.last_device_flag = false;
IanBenzMaxim 77:529edb329ee0 159
IanBenzMaxim 77:529edb329ee0 160 result = OWSearch(searchState);
IanBenzMaxim 77:529edb329ee0 161 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 162 {
IanBenzMaxim 77:529edb329ee0 163 // check if same device found
IanBenzMaxim 77:529edb329ee0 164 if (romId != searchState.romId)
IanBenzMaxim 77:529edb329ee0 165 {
IanBenzMaxim 77:529edb329ee0 166 result = OneWireMaster::OperationFailure;
IanBenzMaxim 77:529edb329ee0 167 }
IanBenzMaxim 77:529edb329ee0 168 }
IanBenzMaxim 77:529edb329ee0 169
IanBenzMaxim 77:529edb329ee0 170 return result;
IanBenzMaxim 77:529edb329ee0 171 }
IanBenzMaxim 77:529edb329ee0 172
IanBenzMaxim 77:529edb329ee0 173 OneWireMaster::CmdResult OneWireMaster::OWReadRom(RomId & romId)
IanBenzMaxim 77:529edb329ee0 174 {
IanBenzMaxim 77:529edb329ee0 175 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 176 RomId readId;
IanBenzMaxim 77:529edb329ee0 177
IanBenzMaxim 77:529edb329ee0 178 result = OWReset();
IanBenzMaxim 77:529edb329ee0 179 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 180 {
IanBenzMaxim 77:529edb329ee0 181 result = OWWriteByte(ReadRomCmd);
IanBenzMaxim 77:529edb329ee0 182 }
IanBenzMaxim 77:529edb329ee0 183
IanBenzMaxim 77:529edb329ee0 184 // read the ROM
IanBenzMaxim 77:529edb329ee0 185 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 186 {
IanBenzMaxim 77:529edb329ee0 187 result = OWReadBlock(readId, RomId::byteLen);
IanBenzMaxim 77:529edb329ee0 188 }
IanBenzMaxim 77:529edb329ee0 189
IanBenzMaxim 77:529edb329ee0 190 // verify CRC8
IanBenzMaxim 77:529edb329ee0 191 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 192 {
IanBenzMaxim 77:529edb329ee0 193 if (readId.crc8Valid())
IanBenzMaxim 77:529edb329ee0 194 {
IanBenzMaxim 77:529edb329ee0 195 romId = readId;
IanBenzMaxim 77:529edb329ee0 196 }
IanBenzMaxim 77:529edb329ee0 197 else
IanBenzMaxim 77:529edb329ee0 198 {
IanBenzMaxim 77:529edb329ee0 199 result = OneWireMaster::OperationFailure;
IanBenzMaxim 77:529edb329ee0 200 }
IanBenzMaxim 77:529edb329ee0 201 }
IanBenzMaxim 77:529edb329ee0 202
IanBenzMaxim 77:529edb329ee0 203 return result;
IanBenzMaxim 77:529edb329ee0 204 }
IanBenzMaxim 77:529edb329ee0 205
IanBenzMaxim 77:529edb329ee0 206 OneWireMaster::CmdResult OneWireMaster::OWSkipRom()
IanBenzMaxim 77:529edb329ee0 207 {
IanBenzMaxim 77:529edb329ee0 208 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 209
IanBenzMaxim 77:529edb329ee0 210 result = OWReset();
IanBenzMaxim 77:529edb329ee0 211 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 212 {
IanBenzMaxim 77:529edb329ee0 213 result = OWWriteByte(SkipRomCmd);
IanBenzMaxim 77:529edb329ee0 214 }
IanBenzMaxim 77:529edb329ee0 215
IanBenzMaxim 77:529edb329ee0 216 return result;
IanBenzMaxim 77:529edb329ee0 217 }
IanBenzMaxim 77:529edb329ee0 218
IanBenzMaxim 77:529edb329ee0 219 OneWireMaster::CmdResult OneWireMaster::OWMatchRom(const RomId & romId)
IanBenzMaxim 77:529edb329ee0 220 {
IanBenzMaxim 77:529edb329ee0 221 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 222
IanBenzMaxim 77:529edb329ee0 223 uint8_t buf[1 + RomId::byteLen];
IanBenzMaxim 77:529edb329ee0 224
IanBenzMaxim 77:529edb329ee0 225 // use MatchROM
IanBenzMaxim 77:529edb329ee0 226 result = OWReset();
IanBenzMaxim 77:529edb329ee0 227 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 228 {
IanBenzMaxim 77:529edb329ee0 229 buf[0] = MatchRomCmd;
IanBenzMaxim 77:529edb329ee0 230 std::memcpy(&buf[1], romId, RomId::byteLen);
IanBenzMaxim 77:529edb329ee0 231 // send command and rom
IanBenzMaxim 77:529edb329ee0 232 result = OWWriteBlock(buf, 1 + RomId::byteLen);
IanBenzMaxim 77:529edb329ee0 233 }
IanBenzMaxim 77:529edb329ee0 234
IanBenzMaxim 77:529edb329ee0 235 return result;
IanBenzMaxim 77:529edb329ee0 236 }
IanBenzMaxim 77:529edb329ee0 237
IanBenzMaxim 77:529edb329ee0 238 OneWireMaster::CmdResult OneWireMaster::OWOverdriveSkipRom()
IanBenzMaxim 77:529edb329ee0 239 {
IanBenzMaxim 77:529edb329ee0 240 OneWireMaster::CmdResult result = OWSetSpeed(OneWireMaster::StandardSpeed);
IanBenzMaxim 77:529edb329ee0 241
IanBenzMaxim 77:529edb329ee0 242 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 243 {
IanBenzMaxim 77:529edb329ee0 244 result = OWReset();
IanBenzMaxim 77:529edb329ee0 245 }
IanBenzMaxim 77:529edb329ee0 246
IanBenzMaxim 77:529edb329ee0 247 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 248 {
IanBenzMaxim 77:529edb329ee0 249 result = OWWriteByte(OverdriveSkipRomCmd);
IanBenzMaxim 77:529edb329ee0 250 }
IanBenzMaxim 77:529edb329ee0 251
IanBenzMaxim 77:529edb329ee0 252 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 253 {
IanBenzMaxim 77:529edb329ee0 254 result = OWSetSpeed(OneWireMaster::OverdriveSpeed);
IanBenzMaxim 77:529edb329ee0 255 }
IanBenzMaxim 77:529edb329ee0 256
IanBenzMaxim 77:529edb329ee0 257 return result;
IanBenzMaxim 77:529edb329ee0 258 }
IanBenzMaxim 77:529edb329ee0 259
IanBenzMaxim 77:529edb329ee0 260 OneWireMaster::CmdResult OneWireMaster::OWOverdriveMatchRom(const RomId & romId)
IanBenzMaxim 77:529edb329ee0 261 {
IanBenzMaxim 77:529edb329ee0 262 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 263
IanBenzMaxim 77:529edb329ee0 264 // use overdrive MatchROM
IanBenzMaxim 77:529edb329ee0 265 OWSetSpeed(OneWireMaster::StandardSpeed);
IanBenzMaxim 77:529edb329ee0 266
IanBenzMaxim 77:529edb329ee0 267 result = OWReset();
IanBenzMaxim 77:529edb329ee0 268 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 269 {
IanBenzMaxim 77:529edb329ee0 270 result = OWWriteByte(OverdriveMatchRomCmd);
IanBenzMaxim 77:529edb329ee0 271 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 272 {
IanBenzMaxim 77:529edb329ee0 273 OWSetSpeed(OneWireMaster::OverdriveSpeed);
IanBenzMaxim 77:529edb329ee0 274 // send ROM
IanBenzMaxim 77:529edb329ee0 275 result = OWWriteBlock(romId, RomId::byteLen);
IanBenzMaxim 77:529edb329ee0 276 }
IanBenzMaxim 77:529edb329ee0 277 }
IanBenzMaxim 77:529edb329ee0 278 return result;
IanBenzMaxim 77:529edb329ee0 279 }
IanBenzMaxim 77:529edb329ee0 280
IanBenzMaxim 77:529edb329ee0 281 OneWireMaster::CmdResult OneWireMaster::OWResume()
IanBenzMaxim 77:529edb329ee0 282 {
IanBenzMaxim 77:529edb329ee0 283 OneWireMaster::CmdResult result;
IanBenzMaxim 77:529edb329ee0 284
IanBenzMaxim 77:529edb329ee0 285 result = OWReset();
IanBenzMaxim 77:529edb329ee0 286 if (result == OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 287 {
IanBenzMaxim 77:529edb329ee0 288 result = OWWriteByte(ResumeCmd);
IanBenzMaxim 77:529edb329ee0 289 }
IanBenzMaxim 77:529edb329ee0 290
IanBenzMaxim 77:529edb329ee0 291 return result;
IanBenzMaxim 77:529edb329ee0 292 }
IanBenzMaxim 77:529edb329ee0 293
IanBenzMaxim 77:529edb329ee0 294 OneWireMaster::CmdResult OneWireMaster::OWSearch(SearchState & searchState)
IanBenzMaxim 77:529edb329ee0 295 {
IanBenzMaxim 77:529edb329ee0 296 uint8_t id_bit_number;
IanBenzMaxim 77:529edb329ee0 297 uint8_t last_zero, rom_byte_number;
IanBenzMaxim 77:529edb329ee0 298 uint8_t id_bit, cmp_id_bit;
IanBenzMaxim 77:529edb329ee0 299 uint8_t rom_byte_mask;
IanBenzMaxim 77:529edb329ee0 300 bool search_result;
IanBenzMaxim 77:529edb329ee0 301 uint8_t crc8 = 0;
IanBenzMaxim 77:529edb329ee0 302 OneWireMaster::SearchDirection search_direction;
IanBenzMaxim 77:529edb329ee0 303
IanBenzMaxim 77:529edb329ee0 304 // initialize for search
IanBenzMaxim 77:529edb329ee0 305 id_bit_number = 1;
IanBenzMaxim 77:529edb329ee0 306 last_zero = 0;
IanBenzMaxim 77:529edb329ee0 307 rom_byte_number = 0;
IanBenzMaxim 77:529edb329ee0 308 rom_byte_mask = 1;
IanBenzMaxim 77:529edb329ee0 309 search_result = false;
IanBenzMaxim 77:529edb329ee0 310
IanBenzMaxim 77:529edb329ee0 311 // if the last call was not the last one
IanBenzMaxim 77:529edb329ee0 312 if (!searchState.last_device_flag)
IanBenzMaxim 77:529edb329ee0 313 {
IanBenzMaxim 77:529edb329ee0 314 // 1-Wire reset
IanBenzMaxim 77:529edb329ee0 315 OneWireMaster::CmdResult result = OWReset();
IanBenzMaxim 77:529edb329ee0 316 if (result != OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 317 {
IanBenzMaxim 77:529edb329ee0 318 // reset the search
IanBenzMaxim 77:529edb329ee0 319 searchState.reset();
IanBenzMaxim 77:529edb329ee0 320 return result;
IanBenzMaxim 77:529edb329ee0 321 }
IanBenzMaxim 77:529edb329ee0 322
IanBenzMaxim 77:529edb329ee0 323 // issue the search command
IanBenzMaxim 77:529edb329ee0 324 OWWriteByte(SearchRomCmd);
IanBenzMaxim 77:529edb329ee0 325
IanBenzMaxim 77:529edb329ee0 326 // loop to do the search
IanBenzMaxim 77:529edb329ee0 327 do
IanBenzMaxim 77:529edb329ee0 328 {
IanBenzMaxim 77:529edb329ee0 329 // if this discrepancy if before the Last Discrepancy
IanBenzMaxim 77:529edb329ee0 330 // on a previous next then pick the same as last time
IanBenzMaxim 77:529edb329ee0 331 if (id_bit_number < searchState.last_discrepancy)
IanBenzMaxim 77:529edb329ee0 332 {
IanBenzMaxim 77:529edb329ee0 333 if ((searchState.romId[rom_byte_number] & rom_byte_mask) > 0)
IanBenzMaxim 77:529edb329ee0 334 {
IanBenzMaxim 77:529edb329ee0 335 search_direction = OneWireMaster::WriteOne;
IanBenzMaxim 77:529edb329ee0 336 }
IanBenzMaxim 77:529edb329ee0 337 else
IanBenzMaxim 77:529edb329ee0 338 {
IanBenzMaxim 77:529edb329ee0 339 search_direction = OneWireMaster::WriteZero;
IanBenzMaxim 77:529edb329ee0 340 }
IanBenzMaxim 77:529edb329ee0 341 }
IanBenzMaxim 77:529edb329ee0 342 else
IanBenzMaxim 77:529edb329ee0 343 {
IanBenzMaxim 77:529edb329ee0 344 // if equal to last pick 1, if not then pick 0
IanBenzMaxim 77:529edb329ee0 345 if (id_bit_number == searchState.last_discrepancy)
IanBenzMaxim 77:529edb329ee0 346 {
IanBenzMaxim 77:529edb329ee0 347 search_direction = OneWireMaster::WriteOne;
IanBenzMaxim 77:529edb329ee0 348 }
IanBenzMaxim 77:529edb329ee0 349 else
IanBenzMaxim 77:529edb329ee0 350 {
IanBenzMaxim 77:529edb329ee0 351 search_direction = OneWireMaster::WriteZero;
IanBenzMaxim 77:529edb329ee0 352 }
IanBenzMaxim 77:529edb329ee0 353 }
IanBenzMaxim 77:529edb329ee0 354
IanBenzMaxim 77:529edb329ee0 355 // Peform a triple operation on the DS2465 which will perform 2 read bits and 1 write bit
IanBenzMaxim 77:529edb329ee0 356 result = OWTriplet(search_direction, id_bit, cmp_id_bit);
IanBenzMaxim 77:529edb329ee0 357 if (result != OneWireMaster::Success)
IanBenzMaxim 77:529edb329ee0 358 {
IanBenzMaxim 77:529edb329ee0 359 return result;
IanBenzMaxim 77:529edb329ee0 360 }
IanBenzMaxim 77:529edb329ee0 361
IanBenzMaxim 77:529edb329ee0 362 // check for no devices on 1-wire
IanBenzMaxim 77:529edb329ee0 363 if (id_bit && cmp_id_bit)
IanBenzMaxim 77:529edb329ee0 364 {
IanBenzMaxim 77:529edb329ee0 365 break;
IanBenzMaxim 77:529edb329ee0 366 }
IanBenzMaxim 77:529edb329ee0 367 else
IanBenzMaxim 77:529edb329ee0 368 {
IanBenzMaxim 77:529edb329ee0 369 if (!id_bit && !cmp_id_bit && (search_direction == OneWireMaster::WriteZero))
IanBenzMaxim 77:529edb329ee0 370 {
IanBenzMaxim 77:529edb329ee0 371 last_zero = id_bit_number;
IanBenzMaxim 77:529edb329ee0 372
IanBenzMaxim 77:529edb329ee0 373 // check for Last discrepancy in family
IanBenzMaxim 77:529edb329ee0 374 if (last_zero < 9)
IanBenzMaxim 77:529edb329ee0 375 {
IanBenzMaxim 77:529edb329ee0 376 searchState.last_family_discrepancy = last_zero;
IanBenzMaxim 77:529edb329ee0 377 }
IanBenzMaxim 77:529edb329ee0 378 }
IanBenzMaxim 77:529edb329ee0 379
IanBenzMaxim 77:529edb329ee0 380 // set or clear the bit in the ROM byte rom_byte_number
IanBenzMaxim 77:529edb329ee0 381 // with mask rom_byte_mask
IanBenzMaxim 77:529edb329ee0 382 if (search_direction == OneWireMaster::WriteOne)
IanBenzMaxim 77:529edb329ee0 383 {
IanBenzMaxim 77:529edb329ee0 384 searchState.romId[rom_byte_number] |= rom_byte_mask;
IanBenzMaxim 77:529edb329ee0 385 }
IanBenzMaxim 77:529edb329ee0 386 else
IanBenzMaxim 77:529edb329ee0 387 {
IanBenzMaxim 77:529edb329ee0 388 searchState.romId[rom_byte_number] &= (uint8_t)~rom_byte_mask;
IanBenzMaxim 77:529edb329ee0 389 }
IanBenzMaxim 77:529edb329ee0 390
IanBenzMaxim 77:529edb329ee0 391 // increment the byte counter id_bit_number
IanBenzMaxim 77:529edb329ee0 392 // and shift the mask rom_byte_mask
IanBenzMaxim 77:529edb329ee0 393 id_bit_number++;
IanBenzMaxim 77:529edb329ee0 394 rom_byte_mask <<= 1;
IanBenzMaxim 77:529edb329ee0 395
IanBenzMaxim 77:529edb329ee0 396 // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
IanBenzMaxim 77:529edb329ee0 397 if (rom_byte_mask == 0)
IanBenzMaxim 77:529edb329ee0 398 {
IanBenzMaxim 77:529edb329ee0 399 crc8 = RomId::calculateCrc8(crc8, searchState.romId[rom_byte_number]); // accumulate the CRC
IanBenzMaxim 77:529edb329ee0 400 rom_byte_number++;
IanBenzMaxim 77:529edb329ee0 401 rom_byte_mask = 1;
IanBenzMaxim 77:529edb329ee0 402 }
IanBenzMaxim 77:529edb329ee0 403 }
IanBenzMaxim 77:529edb329ee0 404 } while (rom_byte_number < RomId::byteLen); // loop until through all ROM bytes 0-7
IanBenzMaxim 77:529edb329ee0 405
IanBenzMaxim 77:529edb329ee0 406 // if the search was successful then
IanBenzMaxim 77:529edb329ee0 407 if (!((id_bit_number <= (RomId::byteLen * 8)) || (crc8 != 0)))
IanBenzMaxim 77:529edb329ee0 408 {
IanBenzMaxim 77:529edb329ee0 409 // search successful so set m_last_discrepancy,m_last_device_flag,search_result
IanBenzMaxim 77:529edb329ee0 410 searchState.last_discrepancy = last_zero;
IanBenzMaxim 77:529edb329ee0 411
IanBenzMaxim 77:529edb329ee0 412 // check for last device
IanBenzMaxim 77:529edb329ee0 413 if (searchState.last_discrepancy == 0)
IanBenzMaxim 77:529edb329ee0 414 {
IanBenzMaxim 77:529edb329ee0 415 searchState.last_device_flag = true;
IanBenzMaxim 77:529edb329ee0 416 }
IanBenzMaxim 77:529edb329ee0 417
IanBenzMaxim 77:529edb329ee0 418 search_result = true;
IanBenzMaxim 77:529edb329ee0 419 }
IanBenzMaxim 77:529edb329ee0 420 }
IanBenzMaxim 77:529edb329ee0 421
IanBenzMaxim 77:529edb329ee0 422 // if no device found then reset counters so next 'search' will be like a first
IanBenzMaxim 77:529edb329ee0 423 if (!search_result || (searchState.romId.familyCode() == 0))
IanBenzMaxim 77:529edb329ee0 424 {
IanBenzMaxim 77:529edb329ee0 425 searchState.reset();
IanBenzMaxim 77:529edb329ee0 426 search_result = false;
IanBenzMaxim 77:529edb329ee0 427 }
IanBenzMaxim 77:529edb329ee0 428
IanBenzMaxim 77:529edb329ee0 429 return (search_result ? OneWireMaster::Success : OneWireMaster::OperationFailure);
IanBenzMaxim 77:529edb329ee0 430 }