Compass Heading

Find which direction on a compass the micro:bit is facing.

The micro:bit measures the compass heading from 0 to 359 degrees with its magnetometer chip. Different numbers mean north, east, south, and west.

input.compassHeading();

Returns

a number from 0 to 359 degrees, which means the compass heading. If the compass isn’t ready, it returns -1003.

Example

This program finds the compass heading and stores it in the degrees variable.

let degrees = input.compassHeading()

Compass simulation

When you run a program that in the simulator, click and drag the compass needle on the screen to change the compass heading.

Example: compass

This program finds the compass heading and then shows a letter that means whether the micro:bit is facing north (N), south (S), east (E), or west (W).

let degrees = 0
basic.forever(() => {
    degrees = input.compassHeading()
    if (degrees < 45) {
        basic.showArrow(ArrowNames.North)
    } else if (degrees < 135) {
        basic.showArrow(ArrowNames.East)
    } else if (degrees < 225) {
        basic.showArrow(ArrowNames.South)
    } else if (degrees < 315) {
        basic.showArrow(ArrowNames.West)
    } else {
        basic.showArrow(ArrowNames.North)
    }
})

Calibration

Every time you start to use the compass (for example, if you have just turned the micro:bit on), the micro:bit will start a calibrate compass (adjust itself). The calibration step will ask you to draw a fill pattern on the screen by tilting the micro:bit.

If you are calibrating or using the compass near metal, it might confuse the micro:bit.

Make a calibration tool

Keep the calibration handy by running it when the user pressed A+B.

input.onButtonPressed(Button.AB, () => {
    input.calibrateCompass();
})