Scratch paint

Step 1: Make it

What is it?

Use your micro:bit to control a Scratch drawing program.

How it works

• This program uses the micro:bit’s accelerometer to guide the pencil sprite around the screen, drawing a line as it moves.
• Tilting the micro:bit left or right makes the pen to move left or right in the X-axis, across the screen.
• Tilting the micro:bit forwards and backwards makes the pen move up and down, in the Y-axis.
• If you tilt it diagonally you get diagonal lines.
• You can control the thickness of the pen lines with micro:bit’s A and B input buttons.
• Shake it to use the micro:bit’s accelerometer input to raise and lower the pen, so you can move around without making a mark.
• The program keeps track the pen’s status (whether it’s up or down) using a variable called penUp. It shows different icons on the micro:bit’s output display so you know if the pen is up or down.

What you need

• micro:bit
• suitable computer with Scratch link installed. See https://scratch.mit.edu/microbit for details on how to get Scratch working with micro:bit.
• optional battery pack

Step 2: Code it

Scratch

Open in Scratch

Download project

Step 3: Improve it

• Add a way of controlling when the colour changes.
• Modify the program so shaking or ‘jumping’ the micro:bit clears the screen.
• Show the pen thickness on the micro:bit’s display.