annotate 1wire.c @ 1:83c649cc59af DANIEL AVR_1_1

Import AVR test code.
author darius
date Sun, 11 Jul 2004 00:45:50 +0930
parents ffeab3c04e83
children f9a085a0ba93
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1 /*
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2 * Various 1 wire routines
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3 * Search routine is copied from the Dallas owpd library with mods.
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4 *
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5 * Copyright (c) 2004
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6 * Daniel O'Connor <darius@dons.net.au>. All rights reserved.
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7 *
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8 * Redistribution and use in source and binary forms, with or without
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9 * modification, are permitted provided that the following conditions
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10 * are met:
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11 * 1. Redistributions of source code must retain the above copyright
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12 * notice, this list of conditions and the following disclaimer.
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13 * 2. Redistributions in binary form must reproduce the above copyright
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14 * notice, this list of conditions and the following disclaimer in the
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15 * documentation and/or other materials provided with the distribution.
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16 *
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17 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20 * ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
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21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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27 * SUCH DAMAGE.
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28 */
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29
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30 #include <stdio.h>
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31 #include <avr/io.h>
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32 #include <avr/pgmspace.h>
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33
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34 #include "1wire.h"
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35
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36 void uart_putsP(const char *addr);
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37 void uart_puts(const char *addr);
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38 void uart_getc();
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39 int uart_putc(char c);
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40
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41 static uint8_t OW_LastDevice = 0;
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42 static uint8_t OW_LastDiscrepancy = 0;
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43 static uint8_t OW_LastFamilyDiscrepancy = 0;
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44
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45 static void
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46 OWdelay(void) {
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47 asm volatile (
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48 "ldi r21, 50\n\t"
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49 "_OWdelay:\n\t"
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50 "nop\n\t"
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51 "nop\n\t"
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52 "nop\n\t"
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53 "nop\n\t"
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54 "nop\n\t"
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55 "nop\n\t"
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56 "nop\n\t"
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57 "nop\n\t"
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58 "nop\n\t"
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59 "nop\n\t"
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60 "nop\n\t"
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61 "nop\n\t"
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62 "nop\n\t"
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63 "dec r21\n\t"
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64 "brne _OWdelay\n\t"
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65 ::: "r21");
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66 }
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67
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68 /*-----------------------------------------------------------------------------
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69 * Generate a 1-Wire reset, return 1 if no presence detect was found,
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70 * return 0 otherwise.
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71 * (NOTE: Does not handle alarm presence from DS2404/DS1994)
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72 */
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73 int
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74 OWTouchReset(void) {
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75 uint8_t result;
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76
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77 asm volatile (
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78 /* Delay G (0 usec) */
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79 "\n\t"
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80 /* Drive bus low */
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81 "cbi %[out], %[opin]\n\t"
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82 "sbi %[ddr], %[opin]\n\t"
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83 /* Delay H (480 usec) */
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84 "ldi r21, 120\n\t"
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85 "loopH:\n\t"
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86 "nop\n\t"
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87 "nop\n\t"
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88 "nop\n\t"
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89 "nop\n\t"
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90 "nop\n\t"
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91 "nop\n\t"
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92 "nop\n\t"
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93 "nop\n\t"
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94 "nop\n\t"
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95 "nop\n\t"
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96 "nop\n\t"
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97 "nop\n\t"
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98 "nop\n\t"
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99 "dec r21\n\t"
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100 "brne loopH\n\t"
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101 /* Release bus */
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102 "cbi %[ddr], %[opin]\n\t"
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103 /* Delay I (70 usec) */
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104 "ldi r21, 35\n\t"
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105 "loopI:\n\t"
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106 "nop\n\t"
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107 "nop\n\t"
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108 "nop\n\t"
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109 "nop\n\t"
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110 "nop\n\t"
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111 "dec r21\n\t"
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112 "brne loopI\n\t"
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113 /* Sample for presense */
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114 "ldi %[result], 0\n\t"
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115 "sbi %[ddr], 1\n\t"
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116 "sbi %[out], 1\n\t"
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117 /* 1 == no presence */
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118 "sbic %[in], %[ipin]\n\t"
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119 "ldi %[result], 1\n\t"
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120 "cbi %[out], 1\n\t"
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121
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122 : [result] "=r" (result) /* Outputs */
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123 : [out] "I" (_SFR_IO_ADDR(OWIREOUTPORT)), /* Inputs */
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124 [ddr] "I" (_SFR_IO_ADDR(OWIREDDR)),
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125 [opin] "I" (OWIREOUTPIN),
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126 [in] "I" (_SFR_IO_ADDR(OWIREINPORT)),
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127 [ipin] "I" (OWIREINPIN)
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128 : "r21"); /* Clobbers */
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129
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130 return(result);
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131 }
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132
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133 /*-----------------------------------------------------------------------------
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134 * Send a 1-wire write bit.
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135 */
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136 void
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137 OWWriteBit(int bit) {
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138 OWdelay();
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139 if (bit) {
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140 asm volatile (
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141 /* Drive bus low */
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142 "cbi %[out], %[pin]\n\t"
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143 "sbi %[ddr], %[pin]\n\t"
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144 /* Delay A (6 usec) */
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145 "ldi r21, 1\n\t"
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146 "loopA:\n\t"
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147 "nop\n\t"
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148 "dec r21\n\t"
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149 "brne loopA\n\t"
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150 /* Release bus */
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151 "cbi %[ddr], %[pin]\n\t"
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152 /* Delay B (64 usec) */
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153 "ldi r21, 32\n\t"
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154 "loopB:\n\t"
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155 "nop\n\t"
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156 "nop\n\t"
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157 "nop\n\t"
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158 "nop\n\t"
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159 "nop\n\t"
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160 "dec r21\n\t"
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161 "brne loopB\n\t"
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162 : /* Outputs */
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163 : [out] "I" (_SFR_IO_ADDR(OWIREOUTPORT)), /* Inputs */
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164 [ddr] "I" (_SFR_IO_ADDR(OWIREDDR)),
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165 [pin] "I" (OWIREOUTPIN)
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166 : "r21"); /* Clobbers */
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167 } else {
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168 asm volatile (
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169 /* Drive bus low */
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170 "cbi %[out], %[pin]\n\t"
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171 "sbi %[ddr], %[pin]\n\t"
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172 /* Delay C (60 usec) */
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173 "ldi r21, 30\n\t"
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174 "loopC:\n\t"
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175 "nop\n\t"
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176 "nop\n\t"
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177 "nop\n\t"
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178 "nop\n\t"
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179 "nop\n\t"
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180 "dec r21\n\t"
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181 "brne loopC\n\t"
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182 /* Release bus */
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183 "cbi %[ddr], %[pin]\n\t"
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184 /* Delay D (10 usec) */
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185 "ldi r21, 9\n\t"
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186 "loopD:\n\t"
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187 "nop\n\t"
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188 "dec r21\n\t"
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189 "brne loopD\n\t"
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190 : /* Outputs */
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191 : [out] "I" (_SFR_IO_ADDR(OWIREOUTPORT)), /* Inputs */
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192 [ddr] "I" (_SFR_IO_ADDR(OWIREDDR)),
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193 [pin] "I" (OWIREOUTPIN)
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194 : "r21"); /* Clobbers */
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195 }
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196 }
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197
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198 /*-----------------------------------------------------------------------------
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199 * Read a bit from the 1-wire bus and return it.
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200 */
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201 int
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202 OWReadBit(void) {
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203 uint8_t result;
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204
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205 OWdelay();
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206
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207 asm volatile (
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208 /* Drive bus low */
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209 "cbi %[out], %[opin]\n\t"
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210 "sbi %[ddr], %[opin]\n\t"
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211 /* Delay A (6 usec) */
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212 "ldi r21, 1\n\t"
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213 "loopA1:\n\t"
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214 "dec r21\n\t"
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215 "brne loopA1\n\t"
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216 /* Release bus */
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217 "cbi %[ddr], %[opin]\n\t"
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218 /* Delay E (9 usec) */
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219 "ldi r21, 8\n\t"
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220 "loopE:\n\t"
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221 "nop\n\t"
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222 "dec r21\n\t"
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223 "brne loopE\n\t"
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224 /* Sample */
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225 "ldi %[res], 0\n\t"
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226 "sbic %[in], %[ipin]\n\t"
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227 "ldi %[res], 1\n\t"
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228
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parents:
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229 /* Delay F (55 usec) */
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parents:
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230 "ldi r21, 27\n\t"
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parents:
diff changeset
231 "loopF:\n\t"
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parents:
diff changeset
232 "nop\n\t"
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parents:
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233 "nop\n\t"
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parents:
diff changeset
234 "nop\n\t"
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parents:
diff changeset
235 "nop\n\t"
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parents:
diff changeset
236 "nop\n\t"
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parents:
diff changeset
237 "nop\n\t"
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parents:
diff changeset
238 "nop\n\t"
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parents:
diff changeset
239 "nop\n\t"
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parents:
diff changeset
240 "nop\n\t"
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parents:
diff changeset
241 "nop\n\t"
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darius
parents:
diff changeset
242 "nop\n\t"
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parents:
diff changeset
243 "nop\n\t"
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darius
parents:
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244 "nop\n\t"
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parents:
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245 "dec r21\n\t"
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parents:
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246 "brne loopF\n\t"
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247
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248 : [res] "=r" (result) /* Outputs */
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249 : [out] "I" (_SFR_IO_ADDR(OWIREOUTPORT)), /* Inputs */
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parents:
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250 [ddr] "I" (_SFR_IO_ADDR(OWIREDDR)),
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parents:
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251 [opin] "I" (OWIREOUTPIN),
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parents:
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252 [in] "I" (_SFR_IO_ADDR(OWIREINPORT)),
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parents:
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253 [ipin] "I" (OWIREINPIN)
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254 : "r21"); /* Clobbers */
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255
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256 return(result);
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parents:
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257 }
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258
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parents:
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259 /*-----------------------------------------------------------------------------
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parents:
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260 * Write a byte to the 1-wire bus
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261 */
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262 void
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263 OWWriteByte(uint8_t data) {
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264 int i;
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265
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266 /* Send LSB first */
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267 for (i = 0; i < 8; i++) {
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268 OWWriteBit(data & 0x01);
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269 data >>= 1;
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270 }
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271 }
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272
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parents:
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273 /*-----------------------------------------------------------------------------
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parents:
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274 * Read a byte from the 1-wire bus
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275 */
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276 int
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277 OWReadByte(void) {
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278 int i, result = 0;
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279
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280 for (i = 0; i < 8; i++) {
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281 result >>= 1;
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282 if (OWReadBit())
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283 result |= 0x80;
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284 }
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285 return(result);
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286 }
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287
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288 /*-----------------------------------------------------------------------------
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parents:
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289 * Write a 1-wire data byte and return the sampled result.
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290 */
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291 int
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292 OWTouchByte(uint8_t data) {
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293 int i, result = 0;
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294
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295 for (i = 0; i < 8; i++) {
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296 result >>= 1;
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297
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298 /* If sending a 1 then read a bit, otherwise write a 0 */
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299 if (data & 0x01) {
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300 if (OWReadBit())
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301 result |= 0x80;
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302 } else
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303 OWWriteBit(0);
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304
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305 data >>= 1;
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306 }
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307
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308 return(result);
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309 }
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310
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311 /*-----------------------------------------------------------------------------
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parents:
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312 * Write a block of bytes to the 1-wire bus and return the sampled result in
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parents:
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313 * the same buffer
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314 */
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315 void
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316 OWBlock(uint8_t *data, int len) {
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317 int i;
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318
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319 for (i = 0; i < len; i++)
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320 data[i] = OWTouchByte(data[i]);
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321 }
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322
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323
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parents:
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324 /*-----------------------------------------------------------------------------
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parents:
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325 * Send a 1 wire command to a device, or all if no ROM ID provided
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326 */
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327 void
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parents:
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328 OWSendCmd(uint8_t *ROM, uint8_t cmd) {
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329 int i;
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330
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331 OWTouchReset();
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332
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333 if (ROM == NULL)
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334 OWWriteByte(OW_SKIP_ROM_CMD);
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335 else {
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336 OWWriteByte(OW_MATCH_ROM_CMD);
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337 for (i = 0; i < 8; i++)
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parents:
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338 OWWriteByte(ROM[i]);
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parents:
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339 }
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parents:
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340
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341 OWWriteByte(cmd);
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parents:
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342 }
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parents:
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343
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parents:
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344 /*-----------------------------------------------------------------------------
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parents:
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345 * Search algorithm from App note 187 (and 162)
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parents:
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346 *
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parents:
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347 * Returns 1 when something is found, 0 if nothing present
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parents:
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348 */
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parents:
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349 int
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parents:
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350 OWFirst(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) {
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351 /* Reset state */
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352 OW_LastDiscrepancy = 0;
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parents:
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353 OW_LastDevice = 0;
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354 OW_LastFamilyDiscrepancy = 0;
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355
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parents:
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356 /* Go looking */
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357 return (OWNext(ROM, do_reset, alarm_only));
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parents:
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358 }
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parents:
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359
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parents:
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360 /* Returns 1 when something is found, 0 if nothing left */
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parents:
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361 int
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parents:
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362 OWNext(uint8_t *ROM, uint8_t do_reset, uint8_t alarm_only) {
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parents:
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363 uint8_t bit_test, search_direction, bit_number;
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parents:
diff changeset
364 uint8_t last_zero, rom_byte_number, next_result;
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parents:
diff changeset
365 uint8_t rom_byte_mask;
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parents:
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366 uint8_t lastcrc8, crcaccum;
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parents:
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367 char errstr[30];
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parents:
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368
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369 /* Init for search */
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370 bit_number = 1;
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parents:
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371 last_zero = 0;
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parents:
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372 rom_byte_number = 0;
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parents:
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373 rom_byte_mask = 1;
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parents:
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374 next_result = 0;
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parents:
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375 lastcrc8 = 0;
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parents:
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376 crcaccum = 0;
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parents:
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377
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parents:
diff changeset
378 /* if the last call was not the last one */
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parents:
diff changeset
379 if (!OW_LastDevice) {
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parents:
diff changeset
380 /* check if reset first is requested */
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parents:
diff changeset
381 if (do_reset) {
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parents:
diff changeset
382 /* reset the 1-wire
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parents:
diff changeset
383 * if there are no parts on 1-wire, return 0 */
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parents:
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384 #if OW_DEBUG
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parents:
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385 uart_putsP(PSTR("Resetting\n\r"));
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parents:
diff changeset
386 #endif
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parents:
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387 if (OWTouchReset()) {
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parents:
diff changeset
388 /* reset the search */
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parents:
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389 OW_LastDiscrepancy = 0;
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parents:
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390 OW_LastFamilyDiscrepancy = 0;
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parents:
diff changeset
391 #if OW_DEBUG
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parents:
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392 uart_putsP(PSTR("No devices on bus\n\r"));
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parents:
diff changeset
393 #endif
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parents:
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394 return 0;
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parents:
diff changeset
395 }
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parents:
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396 }
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parents:
diff changeset
397
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parents:
diff changeset
398 /* If finding alarming devices issue a different command */
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parents:
diff changeset
399 if (alarm_only)
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parents:
diff changeset
400 OWWriteByte(OW_SEARCH_ALRM_CMD); /* issue the alarming search command */
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parents:
diff changeset
401 else
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parents:
diff changeset
402 OWWriteByte(OW_SEARCH_ROM_CMD); /* issue the search command */
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parents:
diff changeset
403
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parents:
diff changeset
404 /* pause before beginning the search */
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parents:
diff changeset
405 OWdelay();
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parents:
diff changeset
406 OWdelay();
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parents:
diff changeset
407 OWdelay();
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parents:
diff changeset
408
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parents:
diff changeset
409 /* loop to do the search */
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parents:
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410 do {
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parents:
diff changeset
411 /* read a bit and its compliment */
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parents:
diff changeset
412 bit_test = OWReadBit() << 1;
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parents:
diff changeset
413 bit_test |= OWReadBit();
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parents:
diff changeset
414
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parents:
diff changeset
415 #if OW_DEBUG
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parents:
diff changeset
416 sprintf_P(errstr, PSTR("bit_test = %d\n\r"), bit_test);
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parents:
diff changeset
417 uart_puts(errstr);
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parents:
diff changeset
418 #endif
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parents:
diff changeset
419
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parents:
diff changeset
420 /* check for no devices on 1-wire */
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parents:
diff changeset
421 if (bit_test == 3) {
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parents:
diff changeset
422 sprintf_P(errstr, PSTR("bit_test = %d\n\r"), bit_test);
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parents:
diff changeset
423 uart_puts(errstr);
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parents:
diff changeset
424 break;
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parents:
diff changeset
425 }
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parents:
diff changeset
426 else {
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darius
parents:
diff changeset
427 /* all devices coupled have 0 or 1 */
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parents:
diff changeset
428 if (bit_test > 0)
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parents:
diff changeset
429 search_direction = !(bit_test & 0x01); /* bit write value for search */
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parents:
diff changeset
430 else {
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darius
parents:
diff changeset
431 /* if this discrepancy is before the Last Discrepancy
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parents:
diff changeset
432 * on a previous OWNext then pick the same as last time */
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parents:
diff changeset
433 if (bit_number < OW_LastDiscrepancy)
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parents:
diff changeset
434 search_direction = ((ROM[rom_byte_number] & rom_byte_mask) > 0);
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parents:
diff changeset
435 else
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darius
parents:
diff changeset
436 /* if equal to last pick 1, if not then pick 0 */
ffeab3c04e83 Initial revision
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parents:
diff changeset
437 search_direction = (bit_number == OW_LastDiscrepancy);
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parents:
diff changeset
438
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darius
parents:
diff changeset
439 /* if 0 was picked then record its position in LastZero */
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parents:
diff changeset
440 if (search_direction == 0) {
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parents:
diff changeset
441 last_zero = bit_number;
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parents:
diff changeset
442
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parents:
diff changeset
443 /* check for Last discrepancy in family */
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parents:
diff changeset
444 if (last_zero < 9)
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parents:
diff changeset
445 OW_LastFamilyDiscrepancy = last_zero;
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parents:
diff changeset
446 }
ffeab3c04e83 Initial revision
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parents:
diff changeset
447 }
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parents:
diff changeset
448
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parents:
diff changeset
449 /* set or clear the bit in the ROM byte rom_byte_number
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darius
parents:
diff changeset
450 * with mask rom_byte_mask */
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parents:
diff changeset
451 if (search_direction == 1)
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parents:
diff changeset
452 ROM[rom_byte_number] |= rom_byte_mask;
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parents:
diff changeset
453 else
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parents:
diff changeset
454 ROM[rom_byte_number] &= ~rom_byte_mask;
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parents:
diff changeset
455
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parents:
diff changeset
456 /* serial number search direction write bit */
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parents:
diff changeset
457 OWWriteBit(search_direction);
ffeab3c04e83 Initial revision
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parents:
diff changeset
458
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parents:
diff changeset
459 /* increment the byte counter bit_number
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darius
parents:
diff changeset
460 * and shift the mask rom_byte_mask */
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parents:
diff changeset
461 bit_number++;
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parents:
diff changeset
462 rom_byte_mask <<= 1;
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parents:
diff changeset
463
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parents:
diff changeset
464 /* if the mask is 0 then go to new ROM byte rom_byte_number
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parents:
diff changeset
465 * and reset mask */
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parents:
diff changeset
466 if (rom_byte_mask == 0) {
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parents:
diff changeset
467 OWCRC(ROM[rom_byte_number], &crcaccum); /* accumulate the CRC */
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468 lastcrc8 = crcaccum;
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469
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470 rom_byte_number++;
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471 rom_byte_mask = 1;
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472 }
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473 }
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474 } while (rom_byte_number < 8); /* loop until through all ROM bytes 0-7 */
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475
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476 /* if the search was successful then */
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477 if (!(bit_number < 65) || lastcrc8) {
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478 if (lastcrc8) {
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479 sprintf_P(errstr, PSTR("Bad CRC (%d)\n\r"), lastcrc8);
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480 uart_puts(errstr);
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481 next_result = 0;
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482 } else {
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483 /* search successful so set LastDiscrepancy,LastDevice,next_result */
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484 OW_LastDiscrepancy = last_zero;
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485 OW_LastDevice = (OW_LastDiscrepancy == 0);
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486 #if OW_DEBUG
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487 sprintf_P(errstr, PSTR("Last device = %d\n\r"), OW_LastDevice);
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488 uart_puts(errstr);
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489 #endif
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490 next_result = 1;
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491 }
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492 }
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493 }
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494
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495 /* if no device found then reset counters so next 'next' will be
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496 * like a first */
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497 if (!next_result || !ROM[0]) {
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498 OW_LastDiscrepancy = 0;
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499 OW_LastDevice = 0;
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500 OW_LastFamilyDiscrepancy = 0;
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501 next_result = 0;
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502 }
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503
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504 return next_result;
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505
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506 }
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507
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508 uint8_t PROGMEM dscrc_table[] = {
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509 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
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510 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
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511 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
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512 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
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513 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
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514 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
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515 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
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516 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
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517 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205,
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518 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80,
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519 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238,
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520 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
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521 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
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522 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
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523 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
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524 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53
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525 };
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526
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527 void
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528 OWCRC(uint8_t x, uint8_t *crc) {
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529 *crc = pgm_read_byte(&dscrc_table[(*crc) ^ x]);
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530 }