Make an RGB LED Blink with micro:bit

Light up and blend the colours of an RGB LED

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Written By: Cherie Tan
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Difficulty

Easy

Steps

11

Time Required

Introduction

You might have already tried your hands at making a two colour LED module blink with the micro:bit, but have you tried using an RGB LED module? 

In this guide, you will learn to make an RGB LED blink and change to a variety of colours. 

Complete this guide to learn the basics of programming an RGB LED!

If you're using the Micro:bit Advent Calendar, you'll need the contents of the bags labelled 2 and 25.

Tools

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    • Let's take a look a closer look at the RGB LED Module before we begin. There are four pins:

      RED (R)

      GREEN (G)

      BLUE (B)

      GND: In electronics, we define a point in a circuit to be a kind of zero volts or 0V reference point, on which to base all other voltage measurements. This point is called ground or GND.

    • Voltage is the difference in electric potential between two points. As it is difficult to talk about voltage without a reference point, we need another point to compare it to.

    • As you might guess, this module is capable of emitting red, green, blue as well as a variety of colours based on how they are combined. This module has on-board resistors, so external resistors are not required here. 

    • Insert the micro:bit into the breakout board

    • Make sure that the micro:bit is inserted in the right orientation, with the buttons facing inward as shown.

    • Now let's program it with the Makecode Editor. 

    • Click on 'Projects' button

    • Click on 'New Project' 

  9. basic.forever(function () {
    pins.digitalWritePin(DigitalPin.P0, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P0, 0)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P1, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P1, 0)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P2, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P2, 0)
    basic.pause(500)
})

    • Copy and paste this code into the Javascript blocks interface. 

  10. basic.forever(function () {
    pins.digitalWritePin(DigitalPin.P0, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P1, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P1, 0)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P2, 1)
    basic.pause(500)
    pins.digitalWritePin(DigitalPin.P2, 0)
    basic.pause(500)
})

    • You can turn on more than one of the colours at the same time. When this happens, the overall colour of the LED will be a blend of the RGB LED colours. Let's try that out and find out what colours you get for each combination!
      Copy and paste this code into the Javascript blocks interface.

    • Give it a try, test out these combinations yourself:

      • RED + GREEN
      • RED + BLUE
      • GREEN + BLUE
      • RED + GREEN + BLUE

    • Connect a microUSB cable to the micro USB port of the micro:bit.

    • Then connect the other end of the cable to your computer or laptop's USB port.

    • Click on the Download button on the bottom left-hand corner 

    • Find the hex file in the Downloads folder or other folder that you might have moved it to

    • Open up Finder on the MacOS or Explorer on Windows, and drag the hex file into MICROBIT under 'Devices' on the macOS.

    • Watch the micro:bit flash for a few seconds and watch the LED blink!