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9 |
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10 | var util = require('util');
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11 | var EventEmitter = require('events').EventEmitter;
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12 |
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13 | var PACKET_CONF = 0x55;
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14 | var ACK_CONF = 0x33;
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15 | var FIN_CONF = 0x16;
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16 |
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17 | var ACK_CMD = 0x00;
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18 | var FIRMWARE_CMD = 0x01;
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19 | var IR_TX_CMD = 0x02;
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20 | var IR_RX_AVAIL_CMD = 0x03;
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21 | var IR_RX_CMD = 0x04;
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22 | var RX_START_CMD = 0x05;
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23 | var RX_STOP_CMD = 0x06;
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24 | var MAX_SIGNAL_DURATION = 200;
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25 |
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26 | var Infrared = function(hardware, callback) {
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27 |
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28 | this.chipSelect = hardware.digital[0];
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29 | this.reset = hardware.digital[1];
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30 | this.irq = hardware.digital[2].rawWrite(false);
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31 | this.spi = hardware.SPI({clockSpeed : 1000, mode:2, chipSelect:this.chipSelect});
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32 | this.transmitting = false;
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33 | this.listening = false;
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34 | this.chipSelect.output().high();
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35 | this.reset.output().high();
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36 |
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37 | var self = this;
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38 |
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39 |
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40 | this.on('newListener', function (event) {
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41 |
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42 | if (event == 'data' && !this.listeners(event).length) {
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43 | self.setListening(1);
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44 | }
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45 | });
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46 |
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47 | this.on('removeListener', function (event) {
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48 |
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49 | if (event == 'data' && !this.listeners(event).length) {
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50 | self.setListening(0);
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51 | }
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52 | });
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53 |
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54 |
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55 | this._establishCommunication(3, function (err, version) {
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56 | if (err) {
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57 | setImmediate(function () {
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58 |
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59 | self.emit('error');
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60 | });
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61 | } else {
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62 | setImmediate(function () {
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63 |
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64 | self.emit('ready');
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65 |
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66 | self.irq.once('high', self._IRQHandler.bind(self));
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67 | });
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68 | }
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69 |
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70 |
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71 | self.setListening( function listeningSet(err) {
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72 |
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73 | if (callback) {
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74 | callback(err, self);
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75 | }
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76 | });
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77 | });
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78 | };
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79 |
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80 | util.inherits(Infrared, EventEmitter);
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81 |
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82 | Infrared.prototype._IRQHandler = function () {
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83 | var self = this;
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84 |
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85 | if (!self.transmitting) {
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86 |
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87 | self._fetchRXDurations(function fetched () {
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88 |
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89 | self.irq.once('high', self._IRQHandler.bind(self));
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90 | });
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91 | } else {
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92 |
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93 | setTimeout(self._IRQHandler.bind(self), 500);
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94 | }
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95 | };
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96 |
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97 | Infrared.prototype.setListening = function (set, callback) {
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98 | var self = this;
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99 |
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100 | var cmd = set ? RX_START_CMD : RX_STOP_CMD;
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101 |
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102 | self.spi.transfer(new Buffer([cmd, 0x00, 0x00]), function listeningSet (err, response) {
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103 | self._validateResponse(response, [PACKET_CONF, cmd], function (valid) {
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104 |
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105 | if (!valid) {
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106 | callback && callback(new Error("Invalid response on setting rx on/off."));
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107 | } else {
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108 | self.listening = set ? true : false;
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109 | callback && callback();
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110 | }
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111 | });
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112 | });
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113 | };
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114 |
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115 | Infrared.prototype._fetchRXDurations = function (callback) {
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116 | var self = this;
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117 |
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118 |
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119 |
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120 | self.spi.transfer(new Buffer([IR_RX_AVAIL_CMD, 0x00, 0x00, 0x00]), function spiComplete (err, response) {
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121 |
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122 |
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123 | self._validateResponse(response, [PACKET_CONF, IR_RX_AVAIL_CMD, 1], function (valid) {
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124 | if (valid) {
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125 | var numInt16 = response[3];
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126 |
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127 |
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128 | var numBytes = numInt16 * 2;
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129 |
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130 | var rxHeader = [IR_RX_CMD, 0x00, 0x00];
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131 | var packet = rxHeader.concat(new Array(numBytes));
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132 |
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133 |
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134 | packet.push(FIN_CONF);
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135 |
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136 | self.spi.transfer(new Buffer(packet), function spiComplete (err, response) {
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137 | var fin = response[response.length - 1];
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138 |
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139 | if (fin != FIN_CONF) {
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140 | console.warn("Warning: Received Packet Out of Frame.");
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141 |
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142 | callback && callback();
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143 | } else {
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144 |
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145 | var buf = response.slice(rxHeader.length, response.length - 1);
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146 |
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147 |
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148 | self.emit('data', buf);
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149 | callback && callback();
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150 | }
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151 | });
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152 | }
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153 | });
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154 | });
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155 | };
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156 |
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157 | Infrared.prototype.sendRawSignal = function (frequency, signalDurations, callback) {
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158 | if (frequency <= 0) {
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159 | callback && callback(new Error("Invalid frequency. Must be greater than zero. Works best between 36-40."));
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160 | return;
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161 | }
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162 |
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163 | if (signalDurations.length > MAX_SIGNAL_DURATION) {
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164 | callback && callback(new Error("Invalid buffer length. Must be between 1 and ", MAX_SIGNAL_DURATION));
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165 | return;
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166 | }
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167 |
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168 | this.transmitting = true;
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169 | var self = this;
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170 |
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171 |
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172 | var tx = this._constructTXPacket(frequency, signalDurations);
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173 |
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174 |
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175 | this.spi.transfer(tx, function spiComplete (err, response) {
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176 | self.transmitting = false;
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177 |
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178 |
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179 | var err = null;
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180 | if (!self._validateResponse(response, [PACKET_CONF, IR_TX_CMD, frequency, signalDurations.length/2])) {
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181 | err = new Error("Invalid response from raw signal packet.");
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182 | }
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183 |
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184 | callback && callback(err);
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185 | });
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186 | };
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187 |
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188 | Infrared.prototype._constructTXPacket = function (frequency, signalDurations) {
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189 |
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190 | var tx = [];
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191 |
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192 | tx.push(IR_TX_CMD);
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193 |
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194 | tx.push(frequency);
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195 |
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196 |
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197 | tx.push(signalDurations.length / 2);
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198 |
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199 |
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200 | for (var i = 0; i < signalDurations.length; i++) {
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201 |
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202 | tx.push(signalDurations.readUInt8(i));
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203 | }
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204 |
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205 | tx.push(0x00);
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206 |
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207 |
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208 | tx.push(FIN_CONF);
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209 |
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210 | return new Buffer(tx);
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211 | };
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212 |
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213 | Infrared.prototype._establishCommunication = function (retries, callback){
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214 | var self = this;
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215 |
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216 | self.getFirmwareVersion(function (err, version) {
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217 |
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218 | if (err) {
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219 |
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220 | retries--;
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221 |
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222 | if (!retries) {
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223 |
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224 | return callback && callback(new Error("Can't connect with module..."));
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225 | }
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226 |
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227 | else {
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228 | self._establishCommunication(retries, callback);
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229 | }
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230 | } else {
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231 |
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232 | self.connected = true;
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233 |
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234 | callback && callback(null, version);
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235 | }
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236 | });
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237 | };
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238 |
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239 | Infrared.prototype.getFirmwareVersion = function (callback) {
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240 | var self = this;
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241 |
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242 | self.spi.transfer(new Buffer([FIRMWARE_CMD, 0x00, 0x00]), function spiComplete (err, response) {
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243 | if (err) {
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244 | return callback(err, null);
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245 | } else if (self._validateResponse(response, [false, FIRMWARE_CMD]) && response.length === 3) {
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246 | callback && callback(null, response[2]);
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247 | } else {
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248 | callback && callback(new Error("Error retrieving Firmware Version"));
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249 | }
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250 | });
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251 | };
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252 |
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253 | Infrared.prototype._validateResponse = function (values, expected, callback) {
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254 | var res = true;
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255 | for (var index = 0; index < expected.length; index++) {
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256 | if (expected[index] == false) {
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257 | continue;
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258 | }
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259 | if (expected[index] != values[index]) {
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260 | res = false;
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261 | break;
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262 | }
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263 | }
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264 |
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265 | callback && callback(res);
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266 | return res;
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267 | };
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268 |
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269 |
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270 |
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271 |
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272 |
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273 |
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274 | exports.Infrared = Infrared;
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275 | exports.use = function (hardware, callback) {
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276 | return new Infrared(hardware, callback);
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277 | };
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