/**
* Based in part on Filipe Vieira'a ITG3200 library for Arduino.
*
* Copyright (c) 2011-2012 Jeff Hoefs <soundanalogous@gmail.com>
* Released under the MIT license. See LICENSE file for details.
*/
JSUTILS.namespace('BO.io.GyroITG3200');
BO.io.GyroITG3200 = (function() {
"use strict";
var GyroITG3200;
// private static constants
var STARTUP_DELAY = 70,
SMPLRT_DIV = 0x15,
DLPF_FS = 0x16,
INT_CFG = 0x17,
GYRO_XOUT = 0x1D,
GYRO_YOUT = 0x1F,
GYRO_ZOUT = 0x21,
PWR_MGM = 0x3E,
NUM_BYTES = 6;
// dependencies
var I2CBase = BO.I2CBase,
Event = JSUTILS.Event,
GyroEvent = BO.io.GyroEvent;
/**
* Creates an interface to an ITG3200 3-axis gyroscope. This gyro measures
* angular acceleration around the x, y, and z axis. This object provides
* the angular velocity of each axis. Proper calibration is required for an
* accurate reading. See [Breakout/examples/sensors/itg3200.html](https://github.com/soundanalogous/Breakout/blob/master/examples/sensors/itg3200.html) and
* [Breakout/examples/processing\_js/gyro.html](https://github.com/soundanalogous/Breakout/blob/master/examples/processing_js/gyro.html) for example applications.
*
* @class GyroITG3200
* @constructor
* @extends BO.I2CBase
* @param {IOBoard} board The IOBoard instance
* @param {Boolean} autoStart True if read continuous mode should start automatically upon instantiation (default is true)
* @param {Number} address The i2c address of the accelerometer. If pin 9 (AD0) of the module is tied to VDD, then use
* `GyroITG3200.ID_AD0_DVV` (0x69), if pin 9 (AD0) is tied to GND, then use `GyroITG3200.ID_AD0_GND`.
* Default = `GyroITG3200.ID_AD0_VDD`
*/
GyroITG3200 = function(board, autoStart, address) {
if (autoStart === undefined) {
autoStart = true;
}
address = address || GyroITG3200.ID_AD0_VDD;
I2CBase.call(this, board, address);
this.name = "GyroITG3200";
// private properties
this._autoStart = autoStart;
this._isReading = false;
this._tempOffsets = {};
this._startupTimer = null;
this._debugMode = BO.enableDebugging;
this._x = 0;
this._y = 0;
this._z = 0;
this._gains = {
x: 1.0,
y: 1.0,
z: 1.0
};
this._offsets = {
x: 0.0,
y: 0.0,
z: 0.0
};
this._polarities = {
x: 0,
y: 0,
z: 0
};
this.setRevPolarity(false, false, false);
this.init();
};
GyroITG3200.prototype = JSUTILS.inherit(I2CBase.prototype);
GyroITG3200.prototype.constructor = GyroITG3200;
Object.defineProperties(GyroITG3200.prototype, {
/**
* [read-only] The x axis output value in degrees.
* @property x
* @type Number
*/
x: {
get: function() {
return this._x / 14.375 * this._polarities.x * this._gains.x + this._offsets.x;
}
},
/**
* [read-only] The y axis output value in degrees.
* @property y
* @type Number
*/
y: {
get: function() {
return this._y / 14.375 * this._polarities.y * this._gains.y + this._offsets.y;
}
},
/**
* [read-only] The z axis output value in degrees.
* @property z
* @type Number
*/
z: {
get: function() {
return this._z / 14.375 * this._polarities.z * this._gains.z + this._offsets.z;
}
},
/**
* [read-only] The raw value of the x axis
* @property rawX
* @type Number
*/
rawX: {
get: function() {
return this._rawX;
}
},
/**
* [read-only] The raw value of the y axis
* @property rawY
* @type Number
*/
rawY: {
get: function() {
return this._rawY;
}
},
/**
* [read-only] The raw value of the z axis
* @property rawZ
* @type Number
*/
rawZ: {
get: function() {
return this._rawZ;
}
},
/**
* [read-only] The state of continuous read mode. True if continuous read mode
* is enabled, false if it is disabled.
* @property isRunning
* @type Boolean
*/
isRunning: {
get: function() {
return this._isReading;
}
}
});
/**
* Set the polarity of the x, y, and z output values.
*
* @method setRevPolarity
* @param {Boolean} xPol Polarity of the x axis
* @param {Boolean} yPol Polarity of the y axis
* @param {Boolean} zPol Polarity of the z axis
*/
GyroITG3200.prototype.setRevPolarity = function(xPol, yPol, zPol) {
this._polarities.x = xPol ? -1 : 1;
this._polarities.y = yPol ? -1 : 1;
this._polarities.z = zPol ? -1 : 1;
};
/**
* Offset the x, y, or z output by the respective input value.
*
* @method setOffsets
* @param {Number} xOffset
* @param {Number} yOffset
* @param {Number} zOffset
*/
GyroITG3200.prototype.setOffsets = function(xOffset, yOffset, zOffset) {
this._offsets.x = xOffset;
this._offsets.y = yOffset;
this._offsets.z = zOffset;
};
/**
* Set the gain value for the x, y, or z output.
*
* @method setGains
* @param {Number} xGain
* @param {Number} yGain
* @param {Number} zGain
*/
GyroITG3200.prototype.setGains = function(xGain, yGain, zGain) {
this._gains.x = xGain;
this._gains.y = yGain;
this._gains.z = zGain;
};
/**
* Start continuous reading of the sensor.
* @method startReading
*/
GyroITG3200.prototype.startReading = function() {
if (!this._isReading) {
this._isReading = true;
this.sendI2CRequest([I2CBase.READ_CONTINUOUS, this.address, GYRO_XOUT, NUM_BYTES]);
}
};
/**
* Stop continuous reading of the sensor.
* @method stopReading
*/
GyroITG3200.prototype.stopReading = function() {
this._isReading = false;
this.sendI2CRequest([I2CBase.STOP_READING, this.address]);
};
/**
* Sends read request to accelerometer and updates accelerometer values.
* @method update
*/
GyroITG3200.prototype.update = function() {
if (this._isReading) {
this.stopReading();
}
// read data: contents of X, Y, and Z registers
this.sendI2CRequest([I2CBase.READ, this.address, GYRO_XOUT, NUM_BYTES]);
};
/**
* @private
* @method init
*/
GyroITG3200.prototype.init = function() {
// set fast sample rate divisor = 0
this.sendI2CRequest([I2CBase.WRITE, this.address, SMPLRT_DIV, 0x00]);
// set range to +-2000 degrees/sec and low pass filter bandwidth to 256Hz and internal sample rate to 8kHz
this.sendI2CRequest([I2CBase.WRITE, this.address, DLPF_FS, 0x18]);
// use internal oscillator
this.sendI2CRequest([I2CBase.WRITE, this.address, PWR_MGM, 0x00]);
// enable ITG ready bit and raw data ready bit
// note: this is probably not necessary if interrupts aren't used
this.sendI2CRequest([I2CBase.WRITE, this.address, INT_CFG, 0x05]);
this._startupTimer = setTimeout(this.onGyroReady.bind(this), STARTUP_DELAY);
};
/**
* @private
* @method onGyroReady
*/
GyroITG3200.prototype.onGyroReady = function() {
this._startupTimer = null;
this.dispatchEvent(new GyroEvent(GyroEvent.GYRO_READY));
if (this._autoStart) {
this.startReading();
}
};
/**
* @private
* @method setRegisterBit
*/
GyroITG3200.prototype.setRegisterBit = function(regAddress, bitPos, state) {
var value;
if (state) {
value |= (1 << bitPos);
} else {
value &= ~(1 << bitPos);
}
this.sendI2CRequest([I2CBase.WRITE, this.address, regAddress, value]);
};
/**
* @private
* @method handleI2C
*/
GyroITG3200.prototype.handleI2C = function(data) {
switch (data[0]) {
case GYRO_XOUT:
this.readGyro(data);
break;
default:
this.debug("Got unexpected register data");
break;
}
};
/**
* @private
* @method readGyro
*/
GyroITG3200.prototype.readGyro = function(data) {
var x_val,
y_val,
z_val;
if (data.length != NUM_BYTES + 1) {
throw new Error("Incorrecte number of bytes returned");
}
x_val = (data[1] << 8) | (data[2]);
y_val = (data[3] << 8) | (data[4]);
z_val = (data[5] << 8) | (data[6]);
if (x_val >> 15) {
this._x = ((x_val ^ 0xFFFF) + 1) * -1;
} else {
this._x = x_val;
}
if (y_val >> 15) {
this._y = ((y_val ^ 0xFFFF) + 1) * -1;
} else {
this._y = y_val;
}
if (z_val >> 15) {
this._z = ((z_val ^ 0xFFFF) + 1) * -1;
} else {
this._z = z_val;
}
this.dispatchEvent(new GyroEvent(GyroEvent.UPDATE));
};
/**
* for debugging
* @private
*/
GyroITG3200.prototype.debug = function(str) {
if (this._debugMode) {
console.log(str);
}
};
// public static constants
/**
* ID = 0x69 if sensor pin 9 (AD0) is tied to Power.
* @property GyroITG3200.ID_AD0_VDD
* @static
*/
GyroITG3200.ID_AD0_VDD = 0x69;
/**
* ID = 0x68 if sensor pin 9 (AD0) is tied to Ground.
* @property GyroITG3200.ID_AD0_VDD
* @static
*/
GyroITG3200.ID_AD0_GND = 0x68;
// document events
/**
* The update event is dispatched when the accelerometer values are updated.
* @type BO.io.GyroEvent.UPDATE
* @event update
* @param {BO.io.GyroITG3200} target A reference to the GyroITG3200 object.
*/
return GyroITG3200;
}());
