Calibrate the MPU9250

The InvenSense MPU9250 is a System in Package (SiP) that combines two chips: the MPU-6500 three-axis Accelerometer and three-axis Gyroscope; and the AK8963 three-axis Magnetometer.

Before using the MPU9250 chip, we need to calibrate different chips.

TIPS

Here we drag a Switch from the Bluetooth Control page to start the Mpu9250 calibration.

_images/tip29.png

The block reads the status of the Switch.

_images/tip30.png

This block is used to calibrate Gyroscope and Accelerometer.

_images/tip32.png

Use the following block to calibrate the Magnetometer.

_images/tip33.png

EXAMPLE

_images/example7.png

Calibrate Accelerometer and Gyroscope

After running the code, place the X Sense HAT horizontally, turn the A switch on and turn it off after 2 seconds, then the calibration is complete.

The X Sense HAT records the current horizontal position as a 0 degree point on the different axes of the Accelerometer and Gyroscope.

Once calibration is complete, press the Joystick on the X Sense HAT to confirm.

Calibrate Magnetometer

The figure below is the coordinate system that will be used to calibrate the magnetometer.

_images/tip34.jpg

Turn the B switch on（keep switch A off）, rotate the X Sense HAT clockwise around the y-axis by 720° and then rotate it back (also 720°), please control the speed so that the process takes about 15s.

_images/tip35.jpg

Similarly, rotate the X Sense HAT clockwise around the x-axis by 720° and then rotate it back (also 720°), please control the speed so that the process takes about 15s.

_images/tip36.jpg

Finally, rotate the X Sense HAT clockwise around the z-axis by 720° and then rotate it back (also 720°), please control the speed so that the process takes about 15s.

Turn off switch B to complete the calibration.

_images/tip37.jpg

Once calibration is complete, press the Joystick on the X Sense HAT to confirm.