Create a motion detecting alarm.
Continuously turn off the RGB LED A and monitor the acceleration strength for motion detection. If it goes over 1100, turn on the RGB LED A for 4 seconds.
basic.forever(function () {
    sb.setRgbLedColorRGB(sb.rgbLed(SBRgbLed.RgbLedA), 0, 0, 0)
    if (input.acceleration(Dimension.Strength) > 1100) {
        sb.setRgbLedColorRGB(sb.rgbLed(SBRgbLed.RgbLedA), 100, 0, 0)
        basic.pause(4000)
    }
})If using micro:bit for the first time, follow this setup.