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Controlling Microbit LEDs


What is an LEDs?


A Light Emitting Diode(LED) is an electrical component that lights up when a current is passed through it.

  • LEDs come in certain voltage ratings – you must use an LED with the correct voltage rating for it to work.
  • LEDs are diodes – devices that only allow current to flow in one direction. If you plug an LED in the wrong way round it wont work.
  • The short leg is usually the negative – end and the long leg is the positive end. Some LEDs also have a flat edge one their base that indicates the negative end.
  • LEDs come in two varieties – Single colour LEDs that give off light of a certain colour. RGB LEDs which can be programmed to display any colour.

Tutorial Video

Wiring Up the components



Click to enlarge


microbit single led with breadboard

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Microsoft Basic Code

JavaScript Code Kingdoms Blocks Code

This code is for the old Code Kingdoms version of the code editor.

flashing led microbit code javascript

Python Code

If you prefer to use text based coding, then you can code using Python!

Wiring multiple LEDs to the Microbit

Wiring up more LEDs is easy, just add more LEDS, resistors and wires from GPIO pins.

Wiring up 3 leds to the Microbit using a breadboard


Challenge 1 – Flashing LED

Follow the tutorial video to get your LED flashing on and off every second.

Challenge 2 – SOS LED

Get your LED to flash the Emergency Morse code SOS

3 times:

  • Long Flash
  • 1 second pause

3 times:

  • Short Flash
  • 1 second pause

3 times:

  • Long Flash
  • 1 second pause

10 second pause



Challenge 3 – Alternating LEDs

Wire up 2 leds and get them to flash alternately every second.

Challenge 4 – Red Yellow Green

Wire up three lights and get them to light:

Red, then yellow, then blue

Challenge 5 – Traffic light LEDs

Wire up 3 LEDs (red,yellow,green) s so that they behave like a set of traffic lights.

  • Green
  • Yellow
  • Red
  • Wait 3 seconds
  • Red and Yellow
  • Green
  • Repeat forever


Challenge 6 – Button operated traffic light

Adapt your challenge 4 code so that the traffic lights are controlled by pressing the button!