1 | var Board = require("./board"),
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2 | events = require("events"),
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3 | util = require("util"),
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4 | __ = require("./fn"),
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5 | Led = require("./led"),
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6 | Sensor = require("./sensor");
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7 |
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8 | var CALIBRATED_MIN_VALUE = 0;
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9 | var CALIBRATED_MAX_VALUE = 1000;
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10 | var LINE_ON_THRESHOLD = 200;
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11 | var LINE_NOISE_THRESHOLD = 50;
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12 |
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13 | var priv = new Map();
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14 |
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15 |
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16 | function initialize() {
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17 | var self = this,
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18 | state = priv.get(this);
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19 |
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20 | if (typeof this.opts.emitter === "undefined") {
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21 | throw new Error("Emitter pin is required");
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22 | }
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23 |
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24 | if (!this.pins || this.pins.length === 0) {
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25 | throw new Error("Pins must be defined");
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26 | }
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27 |
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28 | state.emitter = new Led({
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29 | board: this.board,
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30 | pin: this.opts.emitter
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31 | });
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32 |
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33 | state.sensorStates = this.pins.map(function(pin) {
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34 | var sensorState = {
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35 | sensor: new Sensor({
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36 | board: this.board,
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37 | freq: this.freq,
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38 | pin: pin
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39 | }),
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40 | rawValue: 0,
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41 | dataReceived: false
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42 | };
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43 |
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44 |
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45 | sensorState.sensor.on("data", function() {
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46 | onData.call(self, sensorState, this.value);
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47 | });
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48 |
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49 | return sensorState;
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50 | }, this);
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51 | }
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52 |
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53 | function onData(sensorState, value) {
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54 | var allRead, state = priv.get(this);
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55 |
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56 | sensorState.dataReceived = true;
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57 | sensorState.rawValue = value;
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58 |
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59 | allRead = state.sensorStates.every(function(sensorState) {
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60 | return sensorState.dataReceived;
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61 | });
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62 |
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63 | if (allRead) {
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64 | this.emit("data", this.raw);
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65 |
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66 | if (state.autoCalibrate) {
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67 | setCalibration(state.calibration, this.raw);
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68 | }
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69 |
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70 | if (this.isCalibrated) {
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71 | this.emit("calibratedData", this.values);
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72 | this.emit("line", this.line);
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73 | }
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74 |
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75 | state.sensorStates.forEach(function(sensorState) {
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76 | sensorState.dataReceived = false;
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77 | });
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78 | }
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79 | }
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80 |
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81 | function setCalibration(calibration, values) {
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82 | values.forEach(function(value, i) {
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83 | if (calibration.min[i] === undefined || value < calibration.min[i]) {
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84 | calibration.min[i] = value;
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85 | }
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86 |
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87 | if (calibration.max[i] === undefined || value > calibration.max[i]) {
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88 | calibration.max[i] = value;
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89 | }
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90 | });
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91 | }
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92 |
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93 | function calibrationIsValid(calibration, sensors) {
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94 | return calibration &&
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95 | (calibration.max && calibration.max.length === sensors.length) &&
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96 | (calibration.min && calibration.min.length === sensors.length);
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97 | }
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98 |
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99 |
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100 | function calibratedValues() {
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101 | return this.raw.map(function(value, i) {
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102 | var max = this.calibration.max[i],
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103 | min = this.calibration.min[i];
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104 |
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105 | var scaled = __.scale(value, min, max, CALIBRATED_MIN_VALUE, CALIBRATED_MAX_VALUE);
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106 | return __.constrain(scaled, CALIBRATED_MIN_VALUE, CALIBRATED_MAX_VALUE);
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107 | }, this);
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108 | }
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109 |
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110 | function maxLineValue() {
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111 | return (this.sensors.length - 1) * CALIBRATED_MAX_VALUE;
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112 | }
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113 |
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114 |
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115 |
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116 | function getLine(whiteLine) {
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117 | var onLine = false;
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118 | var avg = 0,
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119 | sum = 0;
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120 | var state = priv.get(this);
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121 |
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122 | whiteLine = !!whiteLine;
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123 |
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124 | this.values.forEach(function(value, i) {
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125 | value = whiteLine ? (CALIBRATED_MAX_VALUE - value) : value;
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126 |
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127 | if (value > LINE_ON_THRESHOLD) {
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128 | onLine = true;
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129 | }
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130 |
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131 | if (value > LINE_NOISE_THRESHOLD) {
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132 | avg += value * i * CALIBRATED_MAX_VALUE;
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133 | sum += value;
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134 | }
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135 | });
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136 |
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137 | if (!onLine) {
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138 | var maxPoint = maxLineValue.call(this) + 1;
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139 | var centerPoint = maxPoint / 2;
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140 |
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141 | return state.lastLine < centerPoint ? 0 : maxPoint;
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142 | }
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143 |
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144 | return state.lastLine = Math.floor(avg / sum);
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145 | }
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146 |
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147 |
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148 | function ReflectanceArray(opts) {
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149 |
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150 | if (!(this instanceof ReflectanceArray)) {
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151 | return new ReflectanceArray(opts);
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152 | }
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153 |
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154 | this.opts = Board.Options(opts);
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155 |
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156 | Board.Component.call(
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157 | this, this.opts, {
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158 | requestPin: false
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159 | }
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160 | );
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161 |
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162 |
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163 | this.freq = opts.freq || 25;
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164 |
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165 |
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166 | var state = {
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167 | lastLine: 0,
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168 | isOn: false,
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169 | calibration: {
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170 | min: [],
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171 | max: []
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172 | },
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173 | autoCalibrate: opts.autoCalibrate || false
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174 | };
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175 |
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176 | priv.set(this, state);
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177 |
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178 | initialize.call(this);
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179 |
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180 | Object.defineProperties(this, {
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181 | isOn: {
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182 | get: function() {
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183 | return state.emitter.isOn;
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184 | }
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185 | },
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186 | isCalibrated: {
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187 | get: function() {
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188 | return calibrationIsValid(this.calibration, this.sensors);
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189 | }
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190 | },
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191 | isOnLine: {
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192 | get: function() {
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193 | var line = this.line;
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194 | return line > CALIBRATED_MIN_VALUE && line < maxLineValue.call(this);
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195 | }
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196 | },
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197 | sensors: {
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198 | get: function() {
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199 | return state.sensorStates.map(function(sensorState) {
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200 | return sensorState.sensor;
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201 | });
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202 | }
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203 | },
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204 | calibration: {
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205 | get: function() {
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206 | return state.calibration;
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207 | }
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208 | },
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209 | raw: {
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210 | get: function() {
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211 | return state.sensorStates.map(function(sensorState) {
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212 | return sensorState.rawValue;
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213 | });
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214 | }
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215 | },
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216 | values: {
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217 | get: function() {
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218 | return this.isCalibrated ? calibratedValues.call(this) : this.raw;
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219 | }
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220 | },
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221 | line: {
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222 | get: function() {
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223 | return this.isCalibrated ? getLine.call(this) : 0;
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224 | }
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225 | }
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226 | });
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227 | }
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228 |
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229 | util.inherits(ReflectanceArray, events.EventEmitter);
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230 |
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231 |
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232 | ReflectanceArray.prototype.enable = function() {
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233 | var state = priv.get(this);
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234 |
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235 | state.emitter.on();
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236 |
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237 | return this;
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238 | };
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239 |
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240 | ReflectanceArray.prototype.disable = function() {
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241 | var state = priv.get(this);
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242 |
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243 | state.emitter.off();
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244 |
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245 | return this;
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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 |
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251 |
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252 | ReflectanceArray.prototype.calibrate = function() {
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253 | var state = priv.get(this);
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254 |
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255 | this.once("data", function(values) {
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256 | setCalibration(state.calibration, values);
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257 |
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258 | this.emit("calibrated");
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259 | });
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260 |
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261 | return this;
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262 | };
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263 |
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264 |
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265 |
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266 |
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267 | ReflectanceArray.prototype.calibrateUntil = function(predicate) {
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268 | var loop = function() {
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269 | this.calibrate();
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270 | this.once("calibrated", function() {
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271 | if (!predicate()) {
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272 | loop();
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273 | }
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274 | });
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275 | }.bind(this);
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276 |
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277 | loop();
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278 |
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279 | return this;
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280 | };
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281 |
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282 |
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283 |
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284 |
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285 | ReflectanceArray.prototype.loadCalibration = function(calibration) {
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286 | var state = priv.get(this);
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287 |
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288 | if (!calibrationIsValid(calibration, this.sensors)) {
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289 | throw new Error("Calibration data not properly set: {min: [], max: []}");
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290 | }
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291 |
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292 | state.calibration = calibration;
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293 |
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294 | return this;
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295 | };
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296 |
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297 | module.exports = ReflectanceArray;
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