Use a Two Colour LED Module with micro:bit
Make a Two Colour LED blink using the micro:bit
Written By: Cherie Tan


Difficulty
Easy

Steps
10
Introduction
Want to make an LED light up and easily change their colours?
In this guide, we will learn to use a handy little LED module and make it blink using the micro:bit!
After completing this guide, you will understand how to use an LED and create a simple program using MakeCode.
If you're using the Micro:bit Advent Calendar, you'll need the contents of the bags labelled 1 and 25.
Step 1 The Module

-
Before we begin, let's take a closer look at the Two Colour LED module! There are three pins:
Signal: This pin is a signal pin, and can be used to emit a green light
Middle Pin : This pin is another signal pin, and can be used to emit a red light
GND: Though it is labelled '-' on the module, this is the ground pin also known as 'GND'. What is '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.
-
You might have noticed an 'R1' on the module, this stands for 'resistor'. However, the resistor here is actually a 0Ω resistor, so we will need to use external resistors in the circuit!
Step 2 Connect module to breadboard
Step 3 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.
-
Insert the micro:bit into the breakout board.
Step 4 Connect GND to -
Step 5 Add Resistor
Step 6 Add another Resistor
Step 7 Connect P0 to Resistor
Step 8 Connect P1 to Resistor
Step 9 Make the LED flash red
basic.forever(function () { pins.digitalWritePin(DigitalPin.P0, 1) basic.pause(250) pins.digitalWritePin(DigitalPin.P0, 0) basic.pause(250) })
-
The first program we will create will make the LED module flash red. So open up the Makecode Editor.
-
Click on the Projects button
-
Create a new document
-
Copy and paste the Javascript code into the Javascript programming interface.
-
Click on the 'blocks' interface button and you should now see the MakeCode blocks.
Step 10 Upload the code to micro:bit



-
First off, click the download button in the bottom left corner of the screen. This will download a hex file (computer program file) which the micro:bit can read.
-
Next, plug in your micro:bit, this will reveal a USB on your computer.
-
Lastly copy across the downloaded file to the micro:bit by dragging and dropping it into the MICRO:BIT drive
-
The micro:bit will flash as the code is being uploaded. Once done, unplug the micro:bit.