IMU

The IMU class constructs objects that represent a single IMU module attached to the physical board. An IMU is an Inertial Measurement Unit. IMUs come in all shapes and DOFs (Degrees of Freedom). They are often made up of several components like Accelerometers, Gyros, Temperature Sensors, and Magnetometers.

Johnny-Five currently supports one kind of IMU:

• MPU-6050

This list will continue to be updated as more devices are confirmed.

Parameters

• General Options

Property Name	Type	Value(s)	Description	Default	Required
controller	string	"MPU6050"	The Name of the controller to use	"MPU6050"	no
freq	Number	ms	The delay in reporting data from this device	100	no

• MPU-6050 Options(controller: "MPU6050")

Property Name	Type	Value(s)	Description	Default	Required
address	Number	8-bit value	The address of the component (can be switched via ADO pin)	0x68	no

// Create an MPU-6050 IMU object:
//
//  - attach SDA and SCL to the I2C pins on your board (A4 and A5 for the Uno)
//  - specify the MPU6050 controller
var accelerometer = new five.IMU({
  controller: "MPU6050",
  address: 0x68, // optional
  freq: 100      // optional
});

Shape

Some of these properties may or may not exist depending on whether the IMU supports it.

{ 
  accelerometer: An instance of `Accelerometer` class. READONLY
  gyro: An instance of `Gyro` class. READONLY
  temperature: An instance of `Temperature` class. READONLY
}

Usage

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

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

  var accelerometer = new five.IMU({
    controller: "MPU6050"
  });

  accelerometer.on("data", function(err, data) {
    console.log("Accelerometer: %d, %d, %d", this.accelerometer.x, this.accelerometer.z, this.accelerometer.z);
    console.log("Gyro: %d, %d, %d", this.gyro.x, this.gyro.z, this.gyro.z);
    console.log("Temperature: %d", this.temperature.celsius);
  });
});

API

The IMU does not have an explicit API. Refer to the individual components for their APIs

Events

• data The "data" event is fired as frequently as the user defined freq will allow in milliseconds.

• change The IMU does not emit "change" events directly. You can watch the aggregate components for "change" events.

Examples

• MPU-6050 IMU