pxt-calliope/docs/reference/input/compass-heading.md
2016-06-11 22:28:57 -04:00

1.5 KiB

Compass Heading

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

The micro:bit measures the compass heading from 0 to 360 degrees with its magnetometer chip. Different numbers mean north, east, south, and west.

input.compassHeading();

Returns

  • a number from 0 to 360 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()

~hint

When you run a program that uses this function in a browser, 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).

basic.forever(() => {
    let degrees = input.compassHeading()
    if (degrees < 45)
        basic.showString("N")
    else if (degrees < 135)
        basic.showString("E")
    else if (degrees < 225)
        basic.showString("S")
    else basic.showString("W")
})

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 to calibrate (adjust itself). It will ask you to draw a circle by tilting the micro:bit.

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

See also

acceleration