Mike Fruge / OneWire

Implementation of 1-Wire with added Alarm Search Functionality

Dependents:   Max32630_One_Wire_Interface

RomId/RomCommands.cpp@142:85b71cfd617e, 2019-08-13 (annotated)

Committer:
mfruge
Date:
Tue Aug 13 14:42:37 2019 +0000
Revision:
142:85b71cfd617e
Parent:
139:f0e0a7976846 
Added functions to ROMCommands to add Alarm Search functionality

Who changed what in which revision?

UserRevisionLine numberNew contents of line
j3 104:3f48daed532b 1 /******************************************************************//**
j3 104:3f48daed532b 2 * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
j3 104:3f48daed532b 3 *
j3 104:3f48daed532b 4 * Permission is hereby granted, free of charge, to any person obtaining a
j3 104:3f48daed532b 5 * copy of this software and associated documentation files (the "Software"),
j3 104:3f48daed532b 6 * to deal in the Software without restriction, including without limitation
j3 104:3f48daed532b 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
j3 104:3f48daed532b 8 * and/or sell copies of the Software, and to permit persons to whom the
j3 104:3f48daed532b 9 * Software is furnished to do so, subject to the following conditions:
j3 104:3f48daed532b 10 *
j3 104:3f48daed532b 11 * The above copyright notice and this permission notice shall be included
j3 104:3f48daed532b 12 * in all copies or substantial portions of the Software.
j3 104:3f48daed532b 13 *
j3 104:3f48daed532b 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
j3 104:3f48daed532b 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
j3 104:3f48daed532b 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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j3 104:3f48daed532b 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
j3 104:3f48daed532b 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
j3 104:3f48daed532b 20 * OTHER DEALINGS IN THE SOFTWARE.
j3 104:3f48daed532b 21 *
j3 104:3f48daed532b 22 * Except as contained in this notice, the name of Maxim Integrated
j3 104:3f48daed532b 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
j3 104:3f48daed532b 24 * Products, Inc. Branding Policy.
j3 104:3f48daed532b 25 *
j3 104:3f48daed532b 26 * The mere transfer of this software does not imply any licenses
j3 104:3f48daed532b 27 * of trade secrets, proprietary technology, copyrights, patents,
j3 104:3f48daed532b 28 * trademarks, maskwork rights, or any other form of intellectual
j3 104:3f48daed532b 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
j3 104:3f48daed532b 30 * ownership rights.
j3 104:3f48daed532b 31 **********************************************************************/
j3 104:3f48daed532b 32
j3 104:3f48daed532b 33 #include "RomId/RomCommands.h"
IanBenzMaxim 90:c233d1c265ff 34
IanBenzMaxim 90:c233d1c265ff 35 using namespace OneWire::crc;
IanBenzMaxim 90:c233d1c265ff 36
IanBenzMaxim 90:c233d1c265ff 37 namespace OneWire
IanBenzMaxim 90:c233d1c265ff 38 {
IanBenzMaxim 90:c233d1c265ff 39 namespace RomCommands
IanBenzMaxim 90:c233d1c265ff 40 {
IanBenzMaxim 90:c233d1c265ff 41 enum OwRomCmd
IanBenzMaxim 90:c233d1c265ff 42 {
IanBenzMaxim 90:c233d1c265ff 43 ReadRomCmd = 0x33,
IanBenzMaxim 90:c233d1c265ff 44 MatchRomCmd = 0x55,
IanBenzMaxim 90:c233d1c265ff 45 SearchRomCmd = 0xF0,
IanBenzMaxim 90:c233d1c265ff 46 SkipRomCmd = 0xCC,
IanBenzMaxim 90:c233d1c265ff 47 ResumeCmd = 0xA5,
IanBenzMaxim 90:c233d1c265ff 48 OverdriveSkipRomCmd = 0x3C,
mfruge 142:85b71cfd617e 49 OverdriveMatchRomCmd = 0x69,
mfruge 142:85b71cfd617e 50 AlarmSearchCmd = 0xEC
IanBenzMaxim 90:c233d1c265ff 51 };
IanBenzMaxim 90:c233d1c265ff 52
IanBenzMaxim 90:c233d1c265ff 53 void SearchState::reset()
IanBenzMaxim 90:c233d1c265ff 54 {
IanBenzMaxim 90:c233d1c265ff 55 last_discrepancy = 0;
IanBenzMaxim 90:c233d1c265ff 56 last_device_flag = false;
IanBenzMaxim 90:c233d1c265ff 57 last_family_discrepancy = 0;
j3 139:f0e0a7976846 58 romId = RomId();
IanBenzMaxim 90:c233d1c265ff 59 }
IanBenzMaxim 90:c233d1c265ff 60
IanBenzMaxim 90:c233d1c265ff 61 void SearchState::findFamily(uint8_t familyCode)
IanBenzMaxim 90:c233d1c265ff 62 {
IanBenzMaxim 90:c233d1c265ff 63 reset();
j3 139:f0e0a7976846 64 romId.familyCode() = familyCode;
IanBenzMaxim 90:c233d1c265ff 65 last_discrepancy = 64;
IanBenzMaxim 90:c233d1c265ff 66 }
IanBenzMaxim 90:c233d1c265ff 67
IanBenzMaxim 90:c233d1c265ff 68 void SearchState::skipCurrentFamily()
IanBenzMaxim 90:c233d1c265ff 69 {
IanBenzMaxim 90:c233d1c265ff 70 // set the Last discrepancy to last family discrepancy
IanBenzMaxim 90:c233d1c265ff 71 last_discrepancy = last_family_discrepancy;
IanBenzMaxim 90:c233d1c265ff 72
IanBenzMaxim 90:c233d1c265ff 73 // clear the last family discrpepancy
IanBenzMaxim 90:c233d1c265ff 74 last_family_discrepancy = 0;
IanBenzMaxim 90:c233d1c265ff 75
IanBenzMaxim 90:c233d1c265ff 76 // check for end of list
IanBenzMaxim 90:c233d1c265ff 77 if (last_discrepancy == 0)
IanBenzMaxim 90:c233d1c265ff 78 {
IanBenzMaxim 90:c233d1c265ff 79 last_device_flag = true;
IanBenzMaxim 90:c233d1c265ff 80 }
IanBenzMaxim 90:c233d1c265ff 81 }
IanBenzMaxim 90:c233d1c265ff 82
IanBenzMaxim 90:c233d1c265ff 83 OneWireMaster::CmdResult OWFirst(OneWireMaster & master, SearchState & searchState)
IanBenzMaxim 90:c233d1c265ff 84 {
IanBenzMaxim 90:c233d1c265ff 85 // Reset and begin a new search
IanBenzMaxim 90:c233d1c265ff 86 searchState.reset();
IanBenzMaxim 90:c233d1c265ff 87 return OWSearch(master, searchState);
IanBenzMaxim 90:c233d1c265ff 88 }
IanBenzMaxim 90:c233d1c265ff 89
IanBenzMaxim 90:c233d1c265ff 90 OneWireMaster::CmdResult OWNext(OneWireMaster & master, SearchState & searchState)
IanBenzMaxim 90:c233d1c265ff 91 {
IanBenzMaxim 90:c233d1c265ff 92 // Continue the previous search
IanBenzMaxim 90:c233d1c265ff 93 return OWSearch(master, searchState);
IanBenzMaxim 90:c233d1c265ff 94 }
IanBenzMaxim 90:c233d1c265ff 95
IanBenzMaxim 90:c233d1c265ff 96 OneWireMaster::CmdResult OWVerify(OneWireMaster & master, const RomId & romId)
IanBenzMaxim 90:c233d1c265ff 97 {
IanBenzMaxim 90:c233d1c265ff 98 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 99 SearchState searchState;
IanBenzMaxim 90:c233d1c265ff 100
IanBenzMaxim 90:c233d1c265ff 101 searchState.romId = romId;
IanBenzMaxim 90:c233d1c265ff 102
IanBenzMaxim 90:c233d1c265ff 103 // set search to find the same device
IanBenzMaxim 90:c233d1c265ff 104 searchState.last_discrepancy = 64;
IanBenzMaxim 90:c233d1c265ff 105 searchState.last_device_flag = false;
IanBenzMaxim 90:c233d1c265ff 106
IanBenzMaxim 90:c233d1c265ff 107 result = OWSearch(master, searchState);
IanBenzMaxim 90:c233d1c265ff 108 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 109 {
IanBenzMaxim 90:c233d1c265ff 110 // check if same device found
IanBenzMaxim 90:c233d1c265ff 111 if (romId != searchState.romId)
IanBenzMaxim 90:c233d1c265ff 112 {
IanBenzMaxim 90:c233d1c265ff 113 result = OneWireMaster::OperationFailure;
IanBenzMaxim 90:c233d1c265ff 114 }
IanBenzMaxim 90:c233d1c265ff 115 }
IanBenzMaxim 90:c233d1c265ff 116
IanBenzMaxim 90:c233d1c265ff 117 return result;
IanBenzMaxim 90:c233d1c265ff 118 }
IanBenzMaxim 90:c233d1c265ff 119
IanBenzMaxim 90:c233d1c265ff 120 OneWireMaster::CmdResult OWReadRom(OneWireMaster & master, RomId & romId)
IanBenzMaxim 90:c233d1c265ff 121 {
IanBenzMaxim 90:c233d1c265ff 122 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 123 RomId readId;
IanBenzMaxim 90:c233d1c265ff 124
IanBenzMaxim 90:c233d1c265ff 125 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 126 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 127 {
IanBenzMaxim 90:c233d1c265ff 128 result = master.OWWriteByte(ReadRomCmd);
IanBenzMaxim 90:c233d1c265ff 129 }
IanBenzMaxim 90:c233d1c265ff 130
IanBenzMaxim 90:c233d1c265ff 131 // read the ROM
IanBenzMaxim 90:c233d1c265ff 132 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 133 {
j3 139:f0e0a7976846 134 result = master.OWReadBlock(readId.buffer.data(), readId.buffer.size());
IanBenzMaxim 90:c233d1c265ff 135 }
IanBenzMaxim 90:c233d1c265ff 136
IanBenzMaxim 90:c233d1c265ff 137 // verify CRC8
IanBenzMaxim 90:c233d1c265ff 138 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 139 {
j3 139:f0e0a7976846 140 if (readId.valid())
IanBenzMaxim 90:c233d1c265ff 141 {
IanBenzMaxim 90:c233d1c265ff 142 romId = readId;
IanBenzMaxim 90:c233d1c265ff 143 }
IanBenzMaxim 90:c233d1c265ff 144 else
IanBenzMaxim 90:c233d1c265ff 145 {
IanBenzMaxim 90:c233d1c265ff 146 result = OneWireMaster::OperationFailure;
IanBenzMaxim 90:c233d1c265ff 147 }
IanBenzMaxim 90:c233d1c265ff 148 }
IanBenzMaxim 90:c233d1c265ff 149
IanBenzMaxim 90:c233d1c265ff 150 return result;
IanBenzMaxim 90:c233d1c265ff 151 }
j3 139:f0e0a7976846 152
IanBenzMaxim 90:c233d1c265ff 153 OneWireMaster::CmdResult OWSkipRom(OneWireMaster & master)
IanBenzMaxim 90:c233d1c265ff 154 {
IanBenzMaxim 90:c233d1c265ff 155 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 156
IanBenzMaxim 90:c233d1c265ff 157 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 158 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 159 {
IanBenzMaxim 90:c233d1c265ff 160 result = master.OWWriteByte(SkipRomCmd);
IanBenzMaxim 90:c233d1c265ff 161 }
IanBenzMaxim 90:c233d1c265ff 162
IanBenzMaxim 90:c233d1c265ff 163 return result;
IanBenzMaxim 90:c233d1c265ff 164 }
j3 139:f0e0a7976846 165
IanBenzMaxim 90:c233d1c265ff 166 OneWireMaster::CmdResult OWMatchRom(OneWireMaster & master, const RomId & romId)
IanBenzMaxim 90:c233d1c265ff 167 {
IanBenzMaxim 90:c233d1c265ff 168 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 169
j3 139:f0e0a7976846 170 uint8_t buf[1 + RomId::Buffer::csize];
IanBenzMaxim 90:c233d1c265ff 171
IanBenzMaxim 90:c233d1c265ff 172 // use MatchROM
IanBenzMaxim 90:c233d1c265ff 173 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 174 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 175 {
IanBenzMaxim 90:c233d1c265ff 176 buf[0] = MatchRomCmd;
j3 139:f0e0a7976846 177 std::memcpy(&buf[1], romId.buffer.data(), romId.buffer.size());
IanBenzMaxim 90:c233d1c265ff 178 // send command and rom
j3 139:f0e0a7976846 179 result = master.OWWriteBlock(buf, 1 + romId.buffer.size());
IanBenzMaxim 90:c233d1c265ff 180 }
IanBenzMaxim 90:c233d1c265ff 181
IanBenzMaxim 90:c233d1c265ff 182 return result;
IanBenzMaxim 90:c233d1c265ff 183 }
j3 139:f0e0a7976846 184
IanBenzMaxim 90:c233d1c265ff 185 OneWireMaster::CmdResult OWOverdriveSkipRom(OneWireMaster & master)
IanBenzMaxim 90:c233d1c265ff 186 {
IanBenzMaxim 90:c233d1c265ff 187 OneWireMaster::CmdResult result = master.OWSetSpeed(OneWireMaster::StandardSpeed);
IanBenzMaxim 90:c233d1c265ff 188
IanBenzMaxim 90:c233d1c265ff 189 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 190 {
IanBenzMaxim 90:c233d1c265ff 191 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 192 }
IanBenzMaxim 90:c233d1c265ff 193
IanBenzMaxim 90:c233d1c265ff 194 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 195 {
IanBenzMaxim 90:c233d1c265ff 196 result = master.OWWriteByte(OverdriveSkipRomCmd);
IanBenzMaxim 90:c233d1c265ff 197 }
IanBenzMaxim 90:c233d1c265ff 198
IanBenzMaxim 90:c233d1c265ff 199 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 200 {
IanBenzMaxim 90:c233d1c265ff 201 result = master.OWSetSpeed(OneWireMaster::OverdriveSpeed);
IanBenzMaxim 90:c233d1c265ff 202 }
IanBenzMaxim 90:c233d1c265ff 203
IanBenzMaxim 90:c233d1c265ff 204 return result;
IanBenzMaxim 90:c233d1c265ff 205 }
IanBenzMaxim 90:c233d1c265ff 206
IanBenzMaxim 90:c233d1c265ff 207 OneWireMaster::CmdResult OWOverdriveMatchRom(OneWireMaster & master, const RomId & romId)
IanBenzMaxim 90:c233d1c265ff 208 {
IanBenzMaxim 90:c233d1c265ff 209 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 210
IanBenzMaxim 90:c233d1c265ff 211 // use overdrive MatchROM
IanBenzMaxim 90:c233d1c265ff 212 master.OWSetSpeed(OneWireMaster::StandardSpeed);
IanBenzMaxim 90:c233d1c265ff 213
IanBenzMaxim 90:c233d1c265ff 214 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 215 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 216 {
IanBenzMaxim 90:c233d1c265ff 217 result = master.OWWriteByte(OverdriveMatchRomCmd);
IanBenzMaxim 90:c233d1c265ff 218 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 219 {
IanBenzMaxim 90:c233d1c265ff 220 master.OWSetSpeed(OneWireMaster::OverdriveSpeed);
IanBenzMaxim 90:c233d1c265ff 221 // send ROM
j3 139:f0e0a7976846 222 result = master.OWWriteBlock(romId.buffer.data(), romId.buffer.size());
IanBenzMaxim 90:c233d1c265ff 223 }
IanBenzMaxim 90:c233d1c265ff 224 }
IanBenzMaxim 90:c233d1c265ff 225 return result;
IanBenzMaxim 90:c233d1c265ff 226 }
j3 139:f0e0a7976846 227
IanBenzMaxim 90:c233d1c265ff 228 OneWireMaster::CmdResult OWResume(OneWireMaster & master)
IanBenzMaxim 90:c233d1c265ff 229 {
IanBenzMaxim 90:c233d1c265ff 230 OneWireMaster::CmdResult result;
IanBenzMaxim 90:c233d1c265ff 231
IanBenzMaxim 90:c233d1c265ff 232 result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 233 if (result == OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 234 {
IanBenzMaxim 90:c233d1c265ff 235 result = master.OWWriteByte(ResumeCmd);
IanBenzMaxim 90:c233d1c265ff 236 }
IanBenzMaxim 90:c233d1c265ff 237
IanBenzMaxim 90:c233d1c265ff 238 return result;
IanBenzMaxim 90:c233d1c265ff 239 }
IanBenzMaxim 90:c233d1c265ff 240
IanBenzMaxim 90:c233d1c265ff 241 OneWireMaster::CmdResult OWSearch(OneWireMaster & master, SearchState & searchState)
IanBenzMaxim 90:c233d1c265ff 242 {
mfruge 142:85b71cfd617e 243 return OWSearchAll(master, searchState, false);
mfruge 142:85b71cfd617e 244 }
mfruge 142:85b71cfd617e 245
mfruge 142:85b71cfd617e 246 OneWireMaster::CmdResult OWAlarmSearch(OneWireMaster & master, SearchState & searchState)
mfruge 142:85b71cfd617e 247 {
mfruge 142:85b71cfd617e 248 return OWSearchAll(master, searchState, true);
mfruge 142:85b71cfd617e 249 }
mfruge 142:85b71cfd617e 250
mfruge 142:85b71cfd617e 251 OneWireMaster::CmdResult OWFirstAlarm(OneWireMaster & master, SearchState & searchState)
mfruge 142:85b71cfd617e 252 {
mfruge 142:85b71cfd617e 253 searchState.reset();
mfruge 142:85b71cfd617e 254 return OWAlarmSearch(master, searchState);
mfruge 142:85b71cfd617e 255 }
mfruge 142:85b71cfd617e 256
mfruge 142:85b71cfd617e 257 OneWireMaster::CmdResult OWNextAlarm(OneWireMaster & master, SearchState & searchState)
mfruge 142:85b71cfd617e 258 {
mfruge 142:85b71cfd617e 259 return OWAlarmSearch(master, searchState);
mfruge 142:85b71cfd617e 260 }
mfruge 142:85b71cfd617e 261
mfruge 142:85b71cfd617e 262 OneWireMaster::CmdResult OWSearchAll(OneWireMaster & master, SearchState & searchState, bool alarmSearch)
mfruge 142:85b71cfd617e 263 {
IanBenzMaxim 90:c233d1c265ff 264 uint8_t id_bit_number;
IanBenzMaxim 90:c233d1c265ff 265 uint8_t last_zero, rom_byte_number;
IanBenzMaxim 90:c233d1c265ff 266 uint8_t id_bit, cmp_id_bit;
IanBenzMaxim 90:c233d1c265ff 267 uint8_t rom_byte_mask;
IanBenzMaxim 90:c233d1c265ff 268 bool search_result;
IanBenzMaxim 90:c233d1c265ff 269 uint8_t crc8 = 0;
IanBenzMaxim 90:c233d1c265ff 270 OneWireMaster::SearchDirection search_direction;
IanBenzMaxim 90:c233d1c265ff 271
IanBenzMaxim 90:c233d1c265ff 272 // initialize for search
IanBenzMaxim 90:c233d1c265ff 273 id_bit_number = 1;
IanBenzMaxim 90:c233d1c265ff 274 last_zero = 0;
IanBenzMaxim 90:c233d1c265ff 275 rom_byte_number = 0;
IanBenzMaxim 90:c233d1c265ff 276 rom_byte_mask = 1;
IanBenzMaxim 90:c233d1c265ff 277 search_result = false;
IanBenzMaxim 90:c233d1c265ff 278
IanBenzMaxim 90:c233d1c265ff 279 // if the last call was not the last one
IanBenzMaxim 90:c233d1c265ff 280 if (!searchState.last_device_flag)
IanBenzMaxim 90:c233d1c265ff 281 {
IanBenzMaxim 90:c233d1c265ff 282 // 1-Wire reset
IanBenzMaxim 90:c233d1c265ff 283 OneWireMaster::CmdResult result = master.OWReset();
IanBenzMaxim 90:c233d1c265ff 284 if (result != OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 285 {
IanBenzMaxim 90:c233d1c265ff 286 // reset the search
IanBenzMaxim 90:c233d1c265ff 287 searchState.reset();
IanBenzMaxim 90:c233d1c265ff 288 return result;
IanBenzMaxim 90:c233d1c265ff 289 }
IanBenzMaxim 90:c233d1c265ff 290
IanBenzMaxim 90:c233d1c265ff 291 // issue the search command
mfruge 142:85b71cfd617e 292 if(alarmSearch){
mfruge 142:85b71cfd617e 293 master.OWWriteByte(AlarmSearchCmd);
mfruge 142:85b71cfd617e 294 }
mfruge 142:85b71cfd617e 295 else{
mfruge 142:85b71cfd617e 296 master.OWWriteByte(SearchRomCmd);
mfruge 142:85b71cfd617e 297 }
IanBenzMaxim 90:c233d1c265ff 298
IanBenzMaxim 90:c233d1c265ff 299 // loop to do the search
IanBenzMaxim 90:c233d1c265ff 300 do
IanBenzMaxim 90:c233d1c265ff 301 {
IanBenzMaxim 90:c233d1c265ff 302 // if this discrepancy if before the Last Discrepancy
IanBenzMaxim 90:c233d1c265ff 303 // on a previous next then pick the same as last time
IanBenzMaxim 90:c233d1c265ff 304 if (id_bit_number < searchState.last_discrepancy)
IanBenzMaxim 90:c233d1c265ff 305 {
j3 139:f0e0a7976846 306 if ((searchState.romId.buffer[rom_byte_number] & rom_byte_mask) > 0)
IanBenzMaxim 90:c233d1c265ff 307 {
IanBenzMaxim 90:c233d1c265ff 308 search_direction = OneWireMaster::WriteOne;
IanBenzMaxim 90:c233d1c265ff 309 }
IanBenzMaxim 90:c233d1c265ff 310 else
IanBenzMaxim 90:c233d1c265ff 311 {
IanBenzMaxim 90:c233d1c265ff 312 search_direction = OneWireMaster::WriteZero;
IanBenzMaxim 90:c233d1c265ff 313 }
IanBenzMaxim 90:c233d1c265ff 314 }
IanBenzMaxim 90:c233d1c265ff 315 else
IanBenzMaxim 90:c233d1c265ff 316 {
IanBenzMaxim 90:c233d1c265ff 317 // if equal to last pick 1, if not then pick 0
IanBenzMaxim 90:c233d1c265ff 318 if (id_bit_number == searchState.last_discrepancy)
IanBenzMaxim 90:c233d1c265ff 319 {
IanBenzMaxim 90:c233d1c265ff 320 search_direction = OneWireMaster::WriteOne;
IanBenzMaxim 90:c233d1c265ff 321 }
IanBenzMaxim 90:c233d1c265ff 322 else
IanBenzMaxim 90:c233d1c265ff 323 {
IanBenzMaxim 90:c233d1c265ff 324 search_direction = OneWireMaster::WriteZero;
IanBenzMaxim 90:c233d1c265ff 325 }
IanBenzMaxim 90:c233d1c265ff 326 }
IanBenzMaxim 90:c233d1c265ff 327
IanBenzMaxim 90:c233d1c265ff 328 // Peform a triple operation on the DS2465 which will perform 2 read bits and 1 write bit
IanBenzMaxim 90:c233d1c265ff 329 result = master.OWTriplet(search_direction, id_bit, cmp_id_bit);
IanBenzMaxim 90:c233d1c265ff 330 if (result != OneWireMaster::Success)
IanBenzMaxim 90:c233d1c265ff 331 {
IanBenzMaxim 90:c233d1c265ff 332 return result;
IanBenzMaxim 90:c233d1c265ff 333 }
IanBenzMaxim 90:c233d1c265ff 334
IanBenzMaxim 90:c233d1c265ff 335 // check for no devices on 1-wire
IanBenzMaxim 90:c233d1c265ff 336 if (id_bit && cmp_id_bit)
IanBenzMaxim 90:c233d1c265ff 337 {
IanBenzMaxim 90:c233d1c265ff 338 break;
IanBenzMaxim 90:c233d1c265ff 339 }
IanBenzMaxim 90:c233d1c265ff 340 else
IanBenzMaxim 90:c233d1c265ff 341 {
IanBenzMaxim 90:c233d1c265ff 342 if (!id_bit && !cmp_id_bit && (search_direction == OneWireMaster::WriteZero))
IanBenzMaxim 90:c233d1c265ff 343 {
IanBenzMaxim 90:c233d1c265ff 344 last_zero = id_bit_number;
IanBenzMaxim 90:c233d1c265ff 345
IanBenzMaxim 90:c233d1c265ff 346 // check for Last discrepancy in family
IanBenzMaxim 90:c233d1c265ff 347 if (last_zero < 9)
IanBenzMaxim 90:c233d1c265ff 348 {
IanBenzMaxim 90:c233d1c265ff 349 searchState.last_family_discrepancy = last_zero;
IanBenzMaxim 90:c233d1c265ff 350 }
IanBenzMaxim 90:c233d1c265ff 351 }
IanBenzMaxim 90:c233d1c265ff 352
IanBenzMaxim 90:c233d1c265ff 353 // set or clear the bit in the ROM byte rom_byte_number
IanBenzMaxim 90:c233d1c265ff 354 // with mask rom_byte_mask
IanBenzMaxim 90:c233d1c265ff 355 if (search_direction == OneWireMaster::WriteOne)
IanBenzMaxim 90:c233d1c265ff 356 {
j3 139:f0e0a7976846 357 searchState.romId.buffer[rom_byte_number] |= rom_byte_mask;
IanBenzMaxim 90:c233d1c265ff 358 }
IanBenzMaxim 90:c233d1c265ff 359 else
IanBenzMaxim 90:c233d1c265ff 360 {
j3 139:f0e0a7976846 361 searchState.romId.buffer[rom_byte_number] &= (uint8_t)~rom_byte_mask;
IanBenzMaxim 90:c233d1c265ff 362 }
IanBenzMaxim 90:c233d1c265ff 363
IanBenzMaxim 90:c233d1c265ff 364 // increment the byte counter id_bit_number
IanBenzMaxim 90:c233d1c265ff 365 // and shift the mask rom_byte_mask
IanBenzMaxim 90:c233d1c265ff 366 id_bit_number++;
IanBenzMaxim 90:c233d1c265ff 367 rom_byte_mask <<= 1;
IanBenzMaxim 90:c233d1c265ff 368
IanBenzMaxim 90:c233d1c265ff 369 // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
IanBenzMaxim 90:c233d1c265ff 370 if (rom_byte_mask == 0)
IanBenzMaxim 90:c233d1c265ff 371 {
j3 139:f0e0a7976846 372 crc8 = calculateCrc8(crc8, searchState.romId.buffer[rom_byte_number]); // accumulate the CRC
IanBenzMaxim 90:c233d1c265ff 373 rom_byte_number++;
IanBenzMaxim 90:c233d1c265ff 374 rom_byte_mask = 1;
IanBenzMaxim 90:c233d1c265ff 375 }
IanBenzMaxim 90:c233d1c265ff 376 }
j3 139:f0e0a7976846 377 } while (rom_byte_number < searchState.romId.buffer.size()); // loop until through all ROM bytes 0-7
IanBenzMaxim 90:c233d1c265ff 378
IanBenzMaxim 90:c233d1c265ff 379 // if the search was successful then
j3 139:f0e0a7976846 380 if (!((id_bit_number <= (searchState.romId.buffer.size() * 8)) || (crc8 != 0)))
IanBenzMaxim 90:c233d1c265ff 381 {
IanBenzMaxim 90:c233d1c265ff 382 // search successful so set m_last_discrepancy,m_last_device_flag,search_result
IanBenzMaxim 90:c233d1c265ff 383 searchState.last_discrepancy = last_zero;
IanBenzMaxim 90:c233d1c265ff 384
IanBenzMaxim 90:c233d1c265ff 385 // check for last device
IanBenzMaxim 90:c233d1c265ff 386 if (searchState.last_discrepancy == 0)
IanBenzMaxim 90:c233d1c265ff 387 {
IanBenzMaxim 90:c233d1c265ff 388 searchState.last_device_flag = true;
IanBenzMaxim 90:c233d1c265ff 389 }
IanBenzMaxim 90:c233d1c265ff 390
IanBenzMaxim 90:c233d1c265ff 391 search_result = true;
IanBenzMaxim 90:c233d1c265ff 392 }
IanBenzMaxim 90:c233d1c265ff 393 }
IanBenzMaxim 90:c233d1c265ff 394
IanBenzMaxim 90:c233d1c265ff 395 // if no device found then reset counters so next 'search' will be like a first
IanBenzMaxim 90:c233d1c265ff 396 if (!search_result || (searchState.romId.familyCode() == 0))
IanBenzMaxim 90:c233d1c265ff 397 {
IanBenzMaxim 90:c233d1c265ff 398 searchState.reset();
IanBenzMaxim 90:c233d1c265ff 399 search_result = false;
IanBenzMaxim 90:c233d1c265ff 400 }
IanBenzMaxim 90:c233d1c265ff 401
IanBenzMaxim 90:c233d1c265ff 402 return (search_result ? OneWireMaster::Success : OneWireMaster::OperationFailure);
IanBenzMaxim 90:c233d1c265ff 403 }
IanBenzMaxim 90:c233d1c265ff 404 }
IanBenzMaxim 90:c233d1c265ff 405 }