lib/mag3110.js
/*
* MAG3110 I2C magnetometer driver
* http://cylonjs.com
*
* Copyright (c) 2014-2016 The Hybrid Group
* Licensed under the Apache 2.0 license.
*/
/*eslint no-undef: "error"*/
/*eslint-env node*/
"use strict";
var Cylon = require("cylon");
var I2CDriver = require("./i2c-driver");
/**
* A MAG3110 Driver
*
* @constructor mag3110
*/
var MAG3110 = module.exports = function MAG3110() {
MAG3110.__super__.constructor.apply(this, arguments);
this.address = this.address || 0x0E;
this.commands = {
getMag: this.getMag
};
};
Cylon.Utils.subclass(MAG3110, I2CDriver);
MAG3110.REG_DR_STATUS = 0x00;
MAG3110.REG_OUT_X_MSB = 0x01;
MAG3110.REG_OUT_X_LSB = 0x02;
MAG3110.REG_OUT_Y_MSB = 0x03;
MAG3110.REG_OUT_Y_LSB = 0x04;
MAG3110.REG_OUT_Z_MSB = 0x05;
MAG3110.REG_OUT_Z_LSB = 0x06;
MAG3110.REG_WHO_AM_I = 0x07;
MAG3110.REG_SYSMOD = 0x08;
MAG3110.REG_OFF_X_MSB = 0x09;
MAG3110.REG_OFF_X_LSB = 0x0A;
MAG3110.REG_OFF_Y_MSB = 0x0B;
MAG3110.REG_OFF_Y_LSB = 0x0C;
MAG3110.REG_OFF_Z_MSB = 0x0D;
MAG3110.REG_OFF_Z_LSB = 0x0E;
MAG3110.REG_DIE_TEMP = 0x0F;
MAG3110.REG_CTRL_REG1 = 0X10;
MAG3110.REG_CTRL_REG2 = 0X11;
MAG3110.MASK_DR = 0xE0;
MAG3110.MASK_OSR = 0x18;
MAG3110.BIT_ACTIVE = 0x0;
MAG3110.BIT_AUTO_RESET = 0x7;
MAG3110.BIT_RAW = 0x5;
MAG3110.BIT_RESET = 0x4;
MAG3110.SYSMOD_STANDBY = 0x0;
MAG3110.SYSMOD_ACTIVE_RAW = 0x1;
MAG3110.SYSMOD_ACTIVE = 0x2;
/**
* Starts the driver
*
* @param {Function} callback triggered when the driver is started
* @return {void}
*/
MAG3110.prototype.start = function(callback) {
this._initMag();
callback();
};
/**
* Gets the value of Magnetometer.
*
* @param {Function} callback callback to be invoked with data
* @return {void}
* @publish
*/
MAG3110.prototype.getMag = function(callback) {
var self = this;
self.connection.i2cRead(self.address,
MAG3110.REG_OFF_MSB,
6,
function(err, d) {
if (err) {
callback(err, null);
} else {
var result = {};
var data = new Buffer(d);
result.x = data.readInt16LE(0);
result.y = data.readInt16LE(2);
result.z = data.readInt16LE(4);
callback(null, result);
}
}
);
};
MAG3110.prototype._initMag = function() {
// set mag into active mode Raw data
// Enable automatic magnetic sensor resets
// by setting bit AUTO_MRST_EN in CTRL_REG2. CTRL_REG2 = 0x80
this.connection.i2cWrite(this.address, MAG3110.REG_CTRL_REG1, 0x01);
// temperature
this.connection.i2cWrite(this.address, MAG3110.REG_DIE_TEMP, 0x0F);
};