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annotate service/arduinoNode/arduino-libraries/OneWire/OneWire.cpp @ 165:af4e9d9f0bd8

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some external arduino libs, minus examples and docs Ignore-this: 444126f11a1755109b3b29cbeaa6b9bd
author drewp@bigasterisk.com
date Sat, 11 Apr 2015 01:43:14 -0700
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1 /*
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2 Copyright (c) 2007, Jim Studt (original old version - many contributors since)
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3
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4 The latest version of this library may be found at:
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5 http://www.pjrc.com/teensy/td_libs_OneWire.html
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6
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7 OneWire has been maintained by Paul Stoffregen (paul@pjrc.com) since
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8 January 2010. At the time, it was in need of many bug fixes, but had
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9 been abandoned the original author (Jim Studt). None of the known
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10 contributors were interested in maintaining OneWire. Paul typically
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11 works on OneWire every 6 to 12 months. Patches usually wait that
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12 long. If anyone is interested in more actively maintaining OneWire,
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13 please contact Paul.
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14
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15 Version 2.2:
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16 Teensy 3.0 compatibility, Paul Stoffregen, paul@pjrc.com
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17 Arduino Due compatibility, http://arduino.cc/forum/index.php?topic=141030
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18 Fix DS18B20 example negative temperature
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19 Fix DS18B20 example's low res modes, Ken Butcher
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20 Improve reset timing, Mark Tillotson
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21 Add const qualifiers, Bertrik Sikken
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22 Add initial value input to crc16, Bertrik Sikken
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23 Add target_search() function, Scott Roberts
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24
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25 Version 2.1:
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26 Arduino 1.0 compatibility, Paul Stoffregen
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27 Improve temperature example, Paul Stoffregen
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28 DS250x_PROM example, Guillermo Lovato
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29 PIC32 (chipKit) compatibility, Jason Dangel, dangel.jason AT gmail.com
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30 Improvements from Glenn Trewitt:
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31 - crc16() now works
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32 - check_crc16() does all of calculation/checking work.
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33 - Added read_bytes() and write_bytes(), to reduce tedious loops.
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34 - Added ds2408 example.
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35 Delete very old, out-of-date readme file (info is here)
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36
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37 Version 2.0: Modifications by Paul Stoffregen, January 2010:
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38 http://www.pjrc.com/teensy/td_libs_OneWire.html
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39 Search fix from Robin James
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40 http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
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41 Use direct optimized I/O in all cases
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42 Disable interrupts during timing critical sections
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43 (this solves many random communication errors)
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44 Disable interrupts during read-modify-write I/O
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45 Reduce RAM consumption by eliminating unnecessary
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46 variables and trimming many to 8 bits
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47 Optimize both crc8 - table version moved to flash
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48
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49 Modified to work with larger numbers of devices - avoids loop.
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50 Tested in Arduino 11 alpha with 12 sensors.
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51 26 Sept 2008 -- Robin James
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52 http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1238032295/27#27
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53
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54 Updated to work with arduino-0008 and to include skip() as of
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55 2007/07/06. --RJL20
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56
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57 Modified to calculate the 8-bit CRC directly, avoiding the need for
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58 the 256-byte lookup table to be loaded in RAM. Tested in arduino-0010
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59 -- Tom Pollard, Jan 23, 2008
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60
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61 Jim Studt's original library was modified by Josh Larios.
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62
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63 Tom Pollard, pollard@alum.mit.edu, contributed around May 20, 2008
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64
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65 Permission is hereby granted, free of charge, to any person obtaining
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66 a copy of this software and associated documentation files (the
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67 "Software"), to deal in the Software without restriction, including
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68 without limitation the rights to use, copy, modify, merge, publish,
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69 distribute, sublicense, and/or sell copies of the Software, and to
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70 permit persons to whom the Software is furnished to do so, subject to
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71 the following conditions:
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72
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73 The above copyright notice and this permission notice shall be
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74 included in all copies or substantial portions of the Software.
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75
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76 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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77 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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78 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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79 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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80 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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81 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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82 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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83
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84 Much of the code was inspired by Derek Yerger's code, though I don't
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85 think much of that remains. In any event that was..
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86 (copyleft) 2006 by Derek Yerger - Free to distribute freely.
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87
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88 The CRC code was excerpted and inspired by the Dallas Semiconductor
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89 sample code bearing this copyright.
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90 //---------------------------------------------------------------------------
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91 // Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.
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92 //
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93 // Permission is hereby granted, free of charge, to any person obtaining a
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94 // copy of this software and associated documentation files (the "Software"),
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95 // to deal in the Software without restriction, including without limitation
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96 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
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97 // and/or sell copies of the Software, and to permit persons to whom the
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98 // Software is furnished to do so, subject to the following conditions:
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99 //
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100 // The above copyright notice and this permission notice shall be included
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101 // in all copies or substantial portions of the Software.
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102 //
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103 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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104 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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105 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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106 // IN NO EVENT SHALL DALLAS SEMICONDUCTOR BE LIABLE FOR ANY CLAIM, DAMAGES
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107 // OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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108 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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109 // OTHER DEALINGS IN THE SOFTWARE.
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110 //
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111 // Except as contained in this notice, the name of Dallas Semiconductor
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112 // shall not be used except as stated in the Dallas Semiconductor
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113 // Branding Policy.
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114 //--------------------------------------------------------------------------
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115 */
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116
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117 #include "OneWire.h"
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118
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119
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120 OneWire::OneWire(uint8_t pin)
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121 {
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122 pinMode(pin, INPUT);
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123 bitmask = PIN_TO_BITMASK(pin);
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124 baseReg = PIN_TO_BASEREG(pin);
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125 #if ONEWIRE_SEARCH
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126 reset_search();
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127 #endif
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128 }
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129
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130
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131 // Perform the onewire reset function. We will wait up to 250uS for
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132 // the bus to come high, if it doesn't then it is broken or shorted
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133 // and we return a 0;
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134 //
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135 // Returns 1 if a device asserted a presence pulse, 0 otherwise.
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136 //
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137 uint8_t OneWire::reset(void)
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138 {
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139 IO_REG_TYPE mask = bitmask;
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140 volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
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141 uint8_t r;
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142 uint8_t retries = 125;
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143
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144 noInterrupts();
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145 DIRECT_MODE_INPUT(reg, mask);
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146 interrupts();
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147 // wait until the wire is high... just in case
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148 do {
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149 if (--retries == 0) return 0;
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150 delayMicroseconds(2);
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151 } while ( !DIRECT_READ(reg, mask));
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152
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153 noInterrupts();
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154 DIRECT_WRITE_LOW(reg, mask);
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155 DIRECT_MODE_OUTPUT(reg, mask); // drive output low
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156 interrupts();
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157 delayMicroseconds(480);
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158 noInterrupts();
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159 DIRECT_MODE_INPUT(reg, mask); // allow it to float
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160 delayMicroseconds(70);
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161 r = !DIRECT_READ(reg, mask);
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162 interrupts();
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163 delayMicroseconds(410);
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164 return r;
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165 }
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166
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167 //
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168 // Write a bit. Port and bit is used to cut lookup time and provide
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169 // more certain timing.
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170 //
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171 void OneWire::write_bit(uint8_t v)
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172 {
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173 IO_REG_TYPE mask=bitmask;
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174 volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
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175
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176 if (v & 1) {
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177 noInterrupts();
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178 DIRECT_WRITE_LOW(reg, mask);
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179 DIRECT_MODE_OUTPUT(reg, mask); // drive output low
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180 delayMicroseconds(10);
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181 DIRECT_WRITE_HIGH(reg, mask); // drive output high
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182 interrupts();
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183 delayMicroseconds(55);
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184 } else {
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185 noInterrupts();
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186 DIRECT_WRITE_LOW(reg, mask);
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187 DIRECT_MODE_OUTPUT(reg, mask); // drive output low
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188 delayMicroseconds(65);
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189 DIRECT_WRITE_HIGH(reg, mask); // drive output high
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190 interrupts();
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191 delayMicroseconds(5);
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192 }
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193 }
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194
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195 //
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196 // Read a bit. Port and bit is used to cut lookup time and provide
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197 // more certain timing.
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198 //
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199 uint8_t OneWire::read_bit(void)
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200 {
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201 IO_REG_TYPE mask=bitmask;
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202 volatile IO_REG_TYPE *reg IO_REG_ASM = baseReg;
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203 uint8_t r;
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204
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205 noInterrupts();
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206 DIRECT_MODE_OUTPUT(reg, mask);
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207 DIRECT_WRITE_LOW(reg, mask);
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208 delayMicroseconds(3);
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209 DIRECT_MODE_INPUT(reg, mask); // let pin float, pull up will raise
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210 delayMicroseconds(10);
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211 r = DIRECT_READ(reg, mask);
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212 interrupts();
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213 delayMicroseconds(53);
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214 return r;
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215 }
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216
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217 //
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218 // Write a byte. The writing code uses the active drivers to raise the
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219 // pin high, if you need power after the write (e.g. DS18S20 in
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220 // parasite power mode) then set 'power' to 1, otherwise the pin will
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221 // go tri-state at the end of the write to avoid heating in a short or
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222 // other mishap.
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223 //
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224 void OneWire::write(uint8_t v, uint8_t power /* = 0 */) {
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225 uint8_t bitMask;
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226
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227 for (bitMask = 0x01; bitMask; bitMask <<= 1) {
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228 OneWire::write_bit( (bitMask & v)?1:0);
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229 }
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230 if ( !power) {
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231 noInterrupts();
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232 DIRECT_MODE_INPUT(baseReg, bitmask);
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233 DIRECT_WRITE_LOW(baseReg, bitmask);
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234 interrupts();
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235 }
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236 }
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237
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238 void OneWire::write_bytes(const uint8_t *buf, uint16_t count, bool power /* = 0 */) {
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239 for (uint16_t i = 0 ; i < count ; i++)
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240 write(buf[i]);
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241 if (!power) {
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242 noInterrupts();
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243 DIRECT_MODE_INPUT(baseReg, bitmask);
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244 DIRECT_WRITE_LOW(baseReg, bitmask);
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245 interrupts();
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246 }
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247 }
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248
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249 //
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250 // Read a byte
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251 //
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252 uint8_t OneWire::read() {
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253 uint8_t bitMask;
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254 uint8_t r = 0;
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255
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256 for (bitMask = 0x01; bitMask; bitMask <<= 1) {
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257 if ( OneWire::read_bit()) r |= bitMask;
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258 }
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259 return r;
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260 }
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261
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262 void OneWire::read_bytes(uint8_t *buf, uint16_t count) {
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263 for (uint16_t i = 0 ; i < count ; i++)
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264 buf[i] = read();
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265 }
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266
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267 //
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268 // Do a ROM select
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269 //
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270 void OneWire::select(const uint8_t rom[8])
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271 {
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272 uint8_t i;
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273
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274 write(0x55); // Choose ROM
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275
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276 for (i = 0; i < 8; i++) write(rom[i]);
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277 }
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278
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279 //
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280 // Do a ROM skip
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281 //
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282 void OneWire::skip()
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283 {
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284 write(0xCC); // Skip ROM
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285 }
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286
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287 void OneWire::depower()
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288 {
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289 noInterrupts();
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290 DIRECT_MODE_INPUT(baseReg, bitmask);
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291 interrupts();
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292 }
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293
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294 #if ONEWIRE_SEARCH
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295
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296 //
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297 // You need to use this function to start a search again from the beginning.
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298 // You do not need to do it for the first search, though you could.
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299 //
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300 void OneWire::reset_search()
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301 {
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302 // reset the search state
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303 LastDiscrepancy = 0;
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304 LastDeviceFlag = FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
305 LastFamilyDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
306 for(int i = 7; ; i--) {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
307 ROM_NO[i] = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
308 if ( i == 0) break;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
309 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
310 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
311
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
312 // Setup the search to find the device type 'family_code' on the next call
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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313 // to search(*newAddr) if it is present.
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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314 //
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
315 void OneWire::target_search(uint8_t family_code)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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316 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
317 // set the search state to find SearchFamily type devices
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
318 ROM_NO[0] = family_code;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
319 for (uint8_t i = 1; i < 8; i++)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
320 ROM_NO[i] = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
321 LastDiscrepancy = 64;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
322 LastFamilyDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
323 LastDeviceFlag = FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
324 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
325
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
326 //
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
327 // Perform a search. If this function returns a '1' then it has
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
328 // enumerated the next device and you may retrieve the ROM from the
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
329 // OneWire::address variable. If there are no devices, no further
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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330 // devices, or something horrible happens in the middle of the
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
331 // enumeration then a 0 is returned. If a new device is found then
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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332 // its address is copied to newAddr. Use OneWire::reset_search() to
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
333 // start over.
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
334 //
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
335 // --- Replaced by the one from the Dallas Semiconductor web site ---
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
336 //--------------------------------------------------------------------------
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
337 // Perform the 1-Wire Search Algorithm on the 1-Wire bus using the existing
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
338 // search state.
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
339 // Return TRUE : device found, ROM number in ROM_NO buffer
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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340 // FALSE : device not found, end of search
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
341 //
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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342 uint8_t OneWire::search(uint8_t *newAddr)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
343 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
344 uint8_t id_bit_number;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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345 uint8_t last_zero, rom_byte_number, search_result;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
346 uint8_t id_bit, cmp_id_bit;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
347
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
348 unsigned char rom_byte_mask, search_direction;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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349
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
350 // initialize for search
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
351 id_bit_number = 1;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
352 last_zero = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
353 rom_byte_number = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
354 rom_byte_mask = 1;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
355 search_result = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
356
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
357 // if the last call was not the last one
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
358 if (!LastDeviceFlag)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
359 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
360 // 1-Wire reset
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
361 if (!reset())
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
362 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
363 // reset the search
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
364 LastDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
365 LastDeviceFlag = FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
366 LastFamilyDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
367 return FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
368 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
369
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
370 // issue the search command
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
371 write(0xF0);
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
372
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
373 // loop to do the search
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
374 do
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
375 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
376 // read a bit and its complement
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
377 id_bit = read_bit();
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
378 cmp_id_bit = read_bit();
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
379
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
380 // check for no devices on 1-wire
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
381 if ((id_bit == 1) && (cmp_id_bit == 1))
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
382 break;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
383 else
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
384 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
385 // all devices coupled have 0 or 1
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
386 if (id_bit != cmp_id_bit)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
387 search_direction = id_bit; // bit write value for search
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
388 else
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
389 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
390 // if this discrepancy if before the Last Discrepancy
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
391 // on a previous next then pick the same as last time
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
392 if (id_bit_number < LastDiscrepancy)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
393 search_direction = ((ROM_NO[rom_byte_number] & rom_byte_mask) > 0);
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
394 else
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
395 // if equal to last pick 1, if not then pick 0
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
396 search_direction = (id_bit_number == LastDiscrepancy);
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
397
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
398 // if 0 was picked then record its position in LastZero
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
399 if (search_direction == 0)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
400 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
401 last_zero = id_bit_number;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
402
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
403 // check for Last discrepancy in family
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
404 if (last_zero < 9)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
405 LastFamilyDiscrepancy = last_zero;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
406 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
407 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
408
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
409 // set or clear the bit in the ROM byte rom_byte_number
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
410 // with mask rom_byte_mask
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
411 if (search_direction == 1)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
412 ROM_NO[rom_byte_number] |= rom_byte_mask;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
413 else
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
414 ROM_NO[rom_byte_number] &= ~rom_byte_mask;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
415
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
416 // serial number search direction write bit
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
417 write_bit(search_direction);
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
418
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
419 // increment the byte counter id_bit_number
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
420 // and shift the mask rom_byte_mask
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
421 id_bit_number++;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
422 rom_byte_mask <<= 1;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
423
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
424 // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
425 if (rom_byte_mask == 0)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
426 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
427 rom_byte_number++;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
428 rom_byte_mask = 1;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
429 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
430 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
431 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
432 while(rom_byte_number < 8); // loop until through all ROM bytes 0-7
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
433
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
434 // if the search was successful then
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
435 if (!(id_bit_number < 65))
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
436 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
437 // search successful so set LastDiscrepancy,LastDeviceFlag,search_result
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
438 LastDiscrepancy = last_zero;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
439
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
440 // check for last device
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
441 if (LastDiscrepancy == 0)
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
442 LastDeviceFlag = TRUE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
443
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
444 search_result = TRUE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
445 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
446 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
447
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
448 // if no device found then reset counters so next 'search' will be like a first
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
449 if (!search_result || !ROM_NO[0])
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
450 {
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
451 LastDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
452 LastDeviceFlag = FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
453 LastFamilyDiscrepancy = 0;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
454 search_result = FALSE;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
455 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
456 for (int i = 0; i < 8; i++) newAddr[i] = ROM_NO[i];
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
457 return search_result;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
458 }
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
459
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
460 #endif
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
parents:
diff changeset
461
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462 #if ONEWIRE_CRC
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463 // The 1-Wire CRC scheme is described in Maxim Application Note 27:
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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464 // "Understanding and Using Cyclic Redundancy Checks with Maxim iButton Products"
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465 //
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466
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467 #if ONEWIRE_CRC8_TABLE
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468 // This table comes from Dallas sample code where it is freely reusable,
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469 // though Copyright (C) 2000 Dallas Semiconductor Corporation
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470 static const uint8_t PROGMEM dscrc_table[] = {
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471 0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
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472 157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,
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drewp@bigasterisk.com
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473 35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,
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drewp@bigasterisk.com
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474 190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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475 70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,
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drewp@bigasterisk.com
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476 219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,
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drewp@bigasterisk.com
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477 101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,
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drewp@bigasterisk.com
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478 248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,
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drewp@bigasterisk.com
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479 140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
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480 17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
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481 175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
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482 50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
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483 202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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484 87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
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drewp@bigasterisk.com
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485 233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
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486 116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53};
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487
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488 //
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489 // Compute a Dallas Semiconductor 8 bit CRC. These show up in the ROM
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490 // and the registers. (note: this might better be done without to
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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491 // table, it would probably be smaller and certainly fast enough
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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492 // compared to all those delayMicrosecond() calls. But I got
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493 // confused, so I use this table from the examples.)
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494 //
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495 uint8_t OneWire::crc8(const uint8_t *addr, uint8_t len)
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496 {
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497 uint8_t crc = 0;
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498
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499 while (len--) {
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500 crc = pgm_read_byte(dscrc_table + (crc ^ *addr++));
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501 }
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502 return crc;
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503 }
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504 #else
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505 //
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diff changeset
506 // Compute a Dallas Semiconductor 8 bit CRC directly.
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drewp@bigasterisk.com
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507 // this is much slower, but much smaller, than the lookup table.
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508 //
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509 uint8_t OneWire::crc8(const uint8_t *addr, uint8_t len)
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510 {
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511 uint8_t crc = 0;
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512
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513 while (len--) {
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514 uint8_t inbyte = *addr++;
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515 for (uint8_t i = 8; i; i--) {
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516 uint8_t mix = (crc ^ inbyte) & 0x01;
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517 crc >>= 1;
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518 if (mix) crc ^= 0x8C;
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519 inbyte >>= 1;
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520 }
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521 }
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522 return crc;
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523 }
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524 #endif
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525
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526 #if ONEWIRE_CRC16
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527 bool OneWire::check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc)
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528 {
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529 crc = ~crc16(input, len, crc);
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530 return (crc & 0xFF) == inverted_crc[0] && (crc >> 8) == inverted_crc[1];
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531 }
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532
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533 uint16_t OneWire::crc16(const uint8_t* input, uint16_t len, uint16_t crc)
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534 {
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535 static const uint8_t oddparity[16] =
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536 { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };
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drewp@bigasterisk.com
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537
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538 for (uint16_t i = 0 ; i < len ; i++) {
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drewp@bigasterisk.com
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diff changeset
539 // Even though we're just copying a byte from the input,
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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540 // we'll be doing 16-bit computation with it.
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drewp@bigasterisk.com
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541 uint16_t cdata = input[i];
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542 cdata = (cdata ^ crc) & 0xff;
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diff changeset
543 crc >>= 8;
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544
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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545 if (oddparity[cdata & 0x0F] ^ oddparity[cdata >> 4])
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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diff changeset
546 crc ^= 0xC001;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
drewp@bigasterisk.com
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diff changeset
547
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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548 cdata <<= 6;
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549 crc ^= cdata;
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550 cdata <<= 1;
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diff changeset
551 crc ^= cdata;
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552 }
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553 return crc;
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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554 }
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diff changeset
555 #endif
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drewp@bigasterisk.com
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diff changeset
556
af4e9d9f0bd8 some external arduino libs, minus examples and docs
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557 #endif