File: src/io/LED.js
/**
* Based on LED.as originally written in as3.
* Copyright (c) the Funnel development team
* http://www.funnel.cc
*
* Ported to JavaScript by Jeff Hoefs
* Copyright (c) 2011-2012 Jeff Hoefs <soundanalogous@gmail.com>
*
* Released under the MIT license. See LICENSE file for details.
*/
JSUTILS.namespace('BO.io.LED');
BO.io.LED = (function() {
var LED;
// Dependencies
var Pin = BO.Pin;
var Oscillator = BO.generators.Oscillator;
/**
* Creates an interface to an LED. This object provides helpful
* methods for blinking and fading LEDs. To use the fading methods, the
* LED must be connected to a PWM pin on the I/O board.
*
* <p>PLEASE NOTE: To use the fade methods, or to use an waveform other
* than `Oscillator.SQUARE` the LED must be connected to a PWM pin.</p>
*
* <p>`SOURCE_DRIVE` vs `SYNC_DRIVE`. If the Anode (longer LED pin) is
* connected to the microcontroller pin, then it is `SOURCE_DRIVE`. If the
* Cathode is connected to the microcontroller pin, then it is
* `SYNC_DRIVE`.</p>
*
* @class LED
* @constructor
* @param {IOBoard} board A reference to the IOBoard the LED is attached to.
* @param {Pin} ledPin A reference to the Pin the LED is connected to.
* @param {Number} driveMode The drive mode of the LED. Must be set to
* `LED.SOURCE_MODE` or `LED.SYNC_MODE`. `SOURCE_MODE` is default.
*/
LED = function(board, ledPin, driveMode) {
"use strict";
this.name = "LED";
this._driveMode = driveMode || LED.SOURCE_DRIVE;
this._pin = ledPin;
this._onValue = 1;
this._offValue = 0;
this._supportsPWM = undefined;
if (this._driveMode === LED.SOURCE_DRIVE) {
this._onValue = 1;
this._offValue = 0;
} else if (this._driveMode === LED.SYNC_DRIVE) {
this._onValue = 0;
this._offValue = 1;
} else {
throw "driveMode should be LED.SOURCE_DRIVE or LED.SYNC_DRIVE";
}
// If the pin supports PWM, set PWM mode else set DOUT mode
if (this._pin.getCapabilities()[Pin.PWM]) {
board.setDigitalPinMode(this._pin.number, Pin.PWM);
this._supportsPWM = true;
} else {
board.setDigitalPinMode(this._pin.number, Pin.DOUT);
this._supportsPWM = false;
}
// Start in the off state
this.off();
};
LED.prototype = {
constructor: LED,
/**
* Get or set the current value (intensity) of the LED.
* @property intensity
* @type Number
*/
get intensity() {
return this._pin.value;
},
set intensity(val) {
// If the pin does not support PWM, force the value to 1 or 0
if (!this._supportsPWM) {
if (val < 0.5) {
val = 0;
} else {
val = 1;
}
}
if (this._driveMode === LED.SOURCE_DRIVE) {
this._pin.value = val;
} else if (this._driveMode === LED.SYNC_DRIVE) {
this._pin.value = 1 - val;
}
},
/**
* Turn the LED on.
* @method on
*/
on: function() {
this._pin.value = this._onValue;
},
/**
* Turn the LED off.
* @method off
*/
off: function() {
this._pin.value = this._offValue;
},
/**
* Check if the LED is on.
* @method isOn
* @return {Boolean} True if the LED is on, false if it is off.
*/
isOn: function() {
return this._pin.value === this._onValue;
},
/**
* Toggle the LED on or off.
* @method toggle
*/
toggle: function() {
this._pin.value = 1 - this._pin.value;
},
/**
* @method blink
* @param {Number} interval The time interval to blink the LED.
* @param {Number} times The number of times the LED should blink.
* A value of 0 will blink forever.
* @param {Function} wave The waveform to apply (default is Oscillator.SQUARE)
* @see BO.generator.Oscillator
*/
blink: function(interval, times, wave) {
var freq = 1000 / interval;
times = times || 0;
wave = wave || Oscillator.SQUARE;
if (!this._supportsPWM && wave !== Oscillator.SQUARE) {
console.log("warning: Only Oscillator.SQUARE may be used on a non-PWM pin.");
console.log("debug: Setting wave to Oscillator.SQUARE.");
wave = Oscillator.SQUARE;
}
//var osc = new Oscillator(wave, freq, 1, 0, 0, times);
this._pin.addGenerator(new Oscillator(wave, freq, 1, 0, 0, times));
//osc.start();
this._pin.generator.start();
},
/**
* Stop the LED blink cycle.
* @method stopBlinking
*/
stopBlinking: function() {
if (this._pin.generator !== null) {
this._pin.generator.stop();
}
this.off();
},
/**
* The LED must be connected to a PWM pin to use this method.
*
* @method fadeIn
* @param {Number} time The fade-in time (in milliseconds).
*/
fadeIn: function(time) {
this.fadeTo(this._onValue, time);
},
/**
* The LED must be connected to a PWM pin to use this method.
*
* @method fadeOut
* @param {Number} time The fade-out time (in milliseconds).
*/
fadeOut: function(time) {
this.fadeTo(this._offValue, time);
},
/**
* The LED must be connected to a PWM pin to use this method.
*
* @method fadeTo
* @param {Number} to The new intensity value to fade to.
* @param {Number} time The fade time (in milliseconds).
*/
fadeTo: function(to, time) {
if (!this._supportsPWM) {
console.log("warning: Fade methods can only be used for LEDs connected to PWM pins.");
return;
}
if (this._driveMode === LED.SYNC_DRIVE) {
to = 1 - to;
}
time = time || 1000;
var freq = 1000 / time;
if (this._pin.value !== to) {
this._pin.addGenerator(new Oscillator(Oscillator.LINEAR, freq, to - this._pin.value, this._pin.value, 0, 1));
this._pin.generator.start();
} else {
this._pin.removeGenerator();
}
}
};
/**
* @property LED.SOURCE_DRIVE
* @static
*/
LED.SOURCE_DRIVE = 0;
/**
* @property LED.SYNC_DRIVE
* @static
*/
LED.SYNC_DRIVE = 1;
return LED;
}());
