IMU Bricklet 3.0¶

Features¶

• Full fledged IMU/AHRS with 9 degrees of freedom (3-axis each: accelerometer, compass, gyroscope)

• No accumulating errors, no gimbal lock!

• Factory calibrated, automatic continuous self-calibration during operation

• Calculates quaternions, linear acceleration, gravity vector as well as independent heading, roll and pitch angles

Description¶

The IMU Bricklet 3.0 offers the same functionality and performance as the IMU Brick 2.0, but in the form-factor of a Bricklet.

The IMU Bricklet 3.0 is equipped with a 3-axis accelerometer, magnetometer (compass) and gyroscope and works as inertial measurement unit. It can measure 9 degrees of freedom and computes quaternions, linear acceleration, gravity vector as well as independent heading, roll and pitch angles. It is a complete attitude and heading reference system.

The API, provided for many programming languages, allows access to the calculated data and also the acceleration, magnetic field and angular velocity of the three axes. If the quaternion representation is used, the IMU Bricklet 3.0 does not have a gimbal lock, as known from Euler angles.

Technical Specifications¶

Resources¶

• BNO055 datasheet (Download)

• Schematic (Download)

• Outline and drilling plan (Download)

• Source code and design files (Download)

• 3D model (View online | Download: STEP, FreeCAD)

Test your IMU Bricklet 3.0¶

To test a IMU Bricklet 3.0 you need to have Brick Daemon and Brick Viewer installed. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon. It helps to figure out basic information about the connected Bricks and Bricklets and allows to test them.

Connect the IMU Bricklet 3.0 to a Brick with a Bricklet Cable.

If you connect the Brick to the PC over USB, you should see a new tab named "IMU Bricklet 3.0" in the Brick Viewer after a moment. Select this tab.

You can see all of the available data form the IMU Bricklet 3.0. If you hold the IMU Bricklet 3.0 in the orientation as shown in the image and press "Save Orientation", the movements that you make with the IMU Bricklet 3.0 should be mirrored in the Brick Viewer.

After this test you can go on with writing your own application. See the Programming Interface section for the API of the IMU Bricklet 3.0 and examples in different programming languages.

Calibration¶

The IMU Bricklet 3.0 does continuous self-calibration during usage. It is not necessary to start a specific manual calibration process. The IMU can store the calibration data to speed-up the self-calibration after each restart. This data is initialized at the factory.

Click the "Calibration" button in Brick Viewer to see the current continuous self-calibration status. The dialog also allows to update the saved calibration data.

Case¶

A laser-cut case for the IMU Bricklet 3.0 is available.

The assembly is easiest if you follow the following steps:

• Screw spacers to the Bricklet,

• screw bottom plate to bottom spacers,

• build up side plates,

• plug side plates into bottom plate and

• screw top plate to top spacers.

Below you can see an exploded assembly drawing of the IMU Bricklet 3.0 case:

Hint: There is a protective film on both sides of the plates, you have to remove it before assembly.

Programming Interface¶

See Programming Interface for a detailed description.