Compass

The Compass class constructs an object that represents a single Compass or Magnetometer.

Supported Compass/Magnetometer:

• HMC6352
• HMC5883L

Parameters

• options An object of property parameters.

Property	Type	Value(s)	Description	Required
controller	String	HMC6352, HMC5883L	Defines the compass module device	yes
gauss	Number	cgs units	Set the scale gauss for compass readings. Defaults to 1.3	no

Shape

{
  heading: The current heading in degrees, 0-360°
  bearing: {
    // Example
    point: "North",
    abbr: "N",
    low: 354.38,
    mid: 360,
    high: 360
  }
}

Component Initialization

var compass = new five.Compass({
  controller: "HMC6352"
});

var compass = new five.Compass({
  controller: "HMC5883L"
});

Usage

var five = require("johnny-five");
var board = new five.Board();

board.on("ready", function() {

  var compass = new five.Compass({
    controller: "HMC6352"
  });

  compass.on("headingchange", function() {
    console.log("headingchange");
    console.log("  heading : ", Math.floor(this.heading));
    console.log("  bearing : ", this.bearing.name);
    console.log("--------------------------------------");
  });

  compass.on("data", function() {
    console.log("  heading : ", Math.floor(this.heading));
    console.log("  bearing : ", this.bearing.name);
    console.log("--------------------------------------");
  });
});

var five = require("johnny-five");
var board = new five.Board();

board.on("ready", function() {

  var compass = new five.Compass({
    controller: "HMC5883L"
  });

  compass.on("headingchange", function() {
    console.log("headingchange");
    console.log("  heading : ", Math.floor(this.heading));
    console.log("  bearing : ", this.bearing.name);
    console.log("--------------------------------------");
  });

  compass.on("data", function() {
    console.log("  heading : ", Math.floor(this.heading));
    console.log("  bearing : ", this.bearing.name);
    console.log("--------------------------------------");
  });
});

API

There are no special API functions for this class.

Events

• change The "change" event is emitted whenever the heading of the compass has changed from it's last position
• data The "data" event is fired as frequently as the user defined freq will allow in milliseconds.

Examples