New version octoliner.js using new interface agreement

modules/@amperka/octoliner.js

@@ -9,31 +9,36 @@ var Octoliner = function(opts) {
     opts.i2c = I2C1;
   }
   this.expander = require('@amperka/gpio-expander').connect(opts);
-  this.expander.pwmFreq(60000);
+  this.expander.pwmFreq(8000);
   this._sensePin = 0;
   this._ledBrightnessPin = 9;
+  this.expander.analogWrite(this._ledBrightnessPin, 1);
   this._sensorPinMap = [4, 5, 6, 8, 7, 3, 2, 1];
   this._lineState = [];
   this.setSensitivity(0.91);
-  this.setBrightness(1);
 };
 
 Octoliner.prototype.setSensitivity = function(sense) {
   this.expander.analogWrite(this._sensePin, sense);
 };
 
-Octoliner.prototype.setBrightness = function(brightness) {
-  this.expander.analogWrite(this._ledBrightnessPin, brightness);
-};
+// deprecated
+Octoliner.prototype.setBrightness = function() {};
 
 Octoliner.prototype.analogRead = function(sensor) {
-  sensor &= 0x07;
-  return this.expander.analogRead(this._sensorPinMap[sensor]);
+  return this.expander.analogRead(this._sensorPinMap[sensor & 0x07]);
+};
+
+Octoliner.prototype.analogReadAll = function() {
+  var result = [0, 0, 0, 0, 0, 0, 0, 0];
+  for (var i = 0; i < 8; i++) {
+    result[i] = this.analogRead(i);
+  }
+  return result;
 };
 
-Octoliner.prototype.digitalRead = function(sensor) {
-  sensor &= 0x07;
-  return this.expander.digitalRead(this._sensorPinMap[sensor]);
+Octoliner.prototype.digitalReadAll = function() {
+  return this.mapAnalogToPattern(this.analogReadAll());
 };
 
 Octoliner.prototype.changeAddr = function(nAddr) {
@@ -44,46 +49,100 @@ Octoliner.prototype.saveAddr = function() {
   this.expander.saveAddr();
 };
 
-Octoliner.prototype.getBinaryLine = function(treshold) {
-  treshold = treshold || 0.5;
-  var result = 0;
-  for (var i = 0; i < 8; ++i) {
-    var value = this.analogRead(i);
-    if (treshold < value) result |= 1 << i;
-  }
-  return result;
+// deprecated
+Octoliner.prototype.mapLine = function(analogArray) {
+  return this.trackLine(analogArray);
+};
+
+Octoliner.prototype.reset = function() {
+  this.expander.reset();
 };
 
-Octoliner.prototype.mapLine = function(Line) {
-  var sum = 0;
-  var avg = 0;
-  var weight = [4, 3, 2, 1, -1, -2, -3, -4];
+Octoliner.prototype.mapAnalogToPattern = function(analogArray) {
+  var pattern = 0;
+  // search min and max values
+  var min = 32767;
+  var max = 0;
   var i;
-  if (Array.isArray(Line)) {
-    for (i = 0; i < 8; i++) {
-      sum += Line[i];
-      avg += Line[i] * weight[i];
-    }
-    if (sum != 0) {
-      return avg / sum / 4.0;
-    }
-    return 0;
-  } else {
-    this._lineState = [];
-    for (i = 0; i < 8; i++) {
-      var mask = 1 << i;
-      if (Line & mask) {
-        this._lineState[i] = 1;
-      } else {
-        this._lineState[i] = 0;
-      }
-    }
-    return this.mapLine(this._lineState);
+  for (i = 0; i < 8; i++) {
+    if (analogArray[i] < min) min = analogArray[i];
+    if (analogArray[i] > max) max = analogArray[i];
+  }
+  // calculate threshold level
+  var threshold = min + (max - min) / 2;
+  // create bit pattern
+  for (i = 0; i < 8; i++) {
+    pattern = (pattern << 1) + (analogArray[i] < threshold ? 0 : 1);
   }
+  return pattern;
 };
 
-Octoliner.prototype.reset = function() {
-  this.expander.reset();
+Octoliner.prototype.mapPatternToLine = function(pattern) {
+  switch (pattern) {
+    case 0x18 /*0b00011000*/:
+      return 0;
+    case 0x10 /*0b00010000*/:
+      return 0.25;
+    case 0x38 /*0b00111000*/:
+      return 0.25;
+    case 0x08 /*0b00001000*/:
+      return -0.25;
+    case 0x1c /*0b00011100*/:
+      return -0.25;
+    case 0x30 /*0b00110000*/:
+      return 0.375;
+    case 0x0c /*0b00001100*/:
+      return -0.375;
+    case 0x20 /*0b00100000*/:
+      return 0.5;
+    case 0x70 /*0b01110000*/:
+      return 0.5;
+    case 0x04 /*0b00000100*/:
+      return -0.5;
+    case 0x0e /*0b00001110*/:
+      return -0.5;
+    case 0x60 /*0b01100000*/:
+      return 0.625;
+    case 0xe0 /*0b11100000*/:
+      return 0.625;
+    case 0x06 /*0b00000110*/:
+      return -0.625;
+    case 0x07 /*0b00000111*/:
+      return -0.625;
+    case 0x40 /*0b01000000*/:
+      return 0.75;
+    case 0xf0 /*0b11110000*/:
+      return 0.75;
+    case 0x02 /*0b00000010*/:
+      return -0.75;
+    case 0x0f /*0b00001111*/:
+      return -0.75;
+    case 0xc0 /*0b11000000*/:
+      return 0.875;
+    case 0x03 /*0b00000011*/:
+      return -0.875;
+    case 0x80 /*0b10000000*/:
+      return 1.0;
+    case 0x01 /*0b00000001*/:
+      return -1.0;
+    default:
+      return NaN;
+  }
+};
+
+Octoliner.prototype.trackLine = function(argument) {
+  if (typeof argument === 'undefined') {
+    // no argument
+    return this.mapPatternToLine(this.digitalReadAll());
+  } else if (Array.isArray(argument)) {
+    // argument is analog array
+    return this.mapPatternToLine(this.mapAnalogToPattern(argument));
+  } else if (typeof argument === 'number') {
+    // argument is pattern
+    return this.mapPatternToLine(argument);
+  } else {
+    return NaN;
+  }
 };
 
 exports.connect = function(opts) {