ProgrammingTheMicrobit.md

Write your first micro:bit program

In the previous step you set up your micro:bit and got to know MakeCode. In this step you will write your first MakeCode program and run it on your micro:bit.

The on start and forever blocks

When you create a new project, you get a workspace with two blocks - on start and forever. These are important blocks and provide a basic structure to your program.

• on start contains blocks that are run when the micro:bit is turned on. These blocks are run once, and are used for setup code such as configuring the radio or setting up variables

• forever contains code that is run repeatedly as long as the micro:bit is powered on. Once all the blocks inside the forever block have executed, they are executed again and again.

Write your first program

If you have coded the micro:bit before, skip this section and jump to building the friend detector.

To ensure everything is working, lets create a simple program to light up the LEDs.

• Expand the Basic section of the toolbox

• Drag a show leds block to inside the on start block on the workspace

  

• Select squares in the 5x5 grid inside the show leds block to select with LEDs you want turned on. For example, draw a heart.

  

You will see the output of this program in the simulator. The LEDs will be lit matching the shape you drew.

Deploy your first program to a micro:bit

To run your program on a physical micro:bit instead of the simulator, you will need to download it onto the micro:bit.

Deploy using MakeCode

If you were able to pair your device with MakeCode:

• Select the Download button on the bottom of the MakeCode screen.

The code will be deployed to the micro:bit, and the micro:bit restarted. The on start block will run and the LEDs will light up.

Deploy manually

If you were not able to pair your device with MakeCode:

• Select the Download button on the bottom of the MakeCode screen

• A file will be downloaded to your downloads folder called microbit-Untitled.hex

• Launch Finder on MacOS or Explorer in Windows

• Find your micro:bit, it will be available as an external drive

• Drag the microbit-Untitled.hex file from your Downloads folder to the micro:bit drive

  

The code will be deployed to the micro:bit, and the micro:bit restarted. The on start block will run and the LEDs will light up.

Run the app

Congratulations, you have created your first micro:bit program. Now let's build the friend detector. Remove the show leds block from the on start block so you have a clean workspace.

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In this step you wrote your first MakeCode program and ran it on your micro:bit. In the next step you will learn how you will build the friend detector, and look at the algorithm you will need to implement.