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/Description	Default	Required
controller	String	"HMC6352", "HMC5883L". Defines the compass module device		yes
gauss	Number	cgs units. Set the scale gauss for compass readings.	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

HMC6352

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

HMC5883L

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