Draw with the ShaKey
Drawing in Scratch is easy, but you're usually tied to using a keyboard.
In this guide, you'll learn to program the ShaKey to act as a paint brush in Scratch and create a paint drawing application.
Complete this guide to get familiar with using Scratch's pen code blocks, 'Events' blocks, as well as how to use randomly generated numbers in your programs.
|Parts Used in This Guide|
Step 1 Scratch editor
Step 2 Add the pen extension
- Click on the 'Extensions' tab
- Click on 'Pen'
Step 3 Create sprite
Next, create a sprite that will represent the point of your pen:
- Click on 'Create a sprite'
- Use the 'Circle' tool to create a small dot
- Name this sprite 'point'
Step 4 Code for start
- Click on the brush 'point' sprite.
- Click on 'Code' tab.
- Add the following blocks.
- When the green flag icon is clicked (the green flag button is located in the upper right corner of the Scratch editor):
- This will reset our drawing board
- The brush 'point' sprite will be at x:0 y:0
- The pen colour will be set to light blue a
- The pen size will be set to 5.
- There's just one little problem with our drawing application! There is no way to clear the screen just yet without the hassle of clicking on the green flag icon each time. This can be easily fixed by using an 'Events' code block. Let's use the 'space' key input here.
Add the same blocks for 'when space key pressed' so that the board can be reset with the space input, too.
Step 5 Code for controls
Likewise, to control the brush, we'll use more 'Events' code blocks. We'll use the up, down, left and right inputs on the ShaKey to control the brush point. Add the following blocks so that:
- When up arrow key pressed, change y by 10
- When down arrow key pressed, change y by -10
- When left arrow key pressed, change x by -10
- When right arrow key pressed, change x by 10
Step 6 Change brush colour
Next, we can add controls for changing the brush colour.
- Click on the 'Operations' tab
These blocks allows us to perform arithmetic operations, generate random numbers, and compare numeric values to determine their relationship to one another. Here, we'll generate a random number to pick a different colour for the brush!
- Get a 'pick random ... to ... ' block.
- Change its values to 1 and 50.
Step 7 Make a clone of the brush
To make a clone of the brush, we'll use another 'Events' code block.
- Set it as 'when s key pressed' to use the ShaKey's shake feature to create a clone.
- We'll use a 'pick random ... to ... ' block to select a random colour for the pen, then again when choosing a position for the clone.
Step 8 Code to hide brush point sprite
Step 9 Remap ShaKey using Arduino sketch
Finally, we'll program the ShaKey's shake feature. Before we can do so, we'll need the Arduino IDE set up for ShaKey. Follow these steps:
- If you haven't done so yet, check out Set up Arduino IDE for ShaKey.
- Connect the ShaKey to your computer via a microUSB cable.
- Then to get the ShaKey's 'shake' feature working with Scratch, download this sketch: ShaKey-remap.zip
- Verify and upload the 'ShaKey-modified.ino' file to the ShaKey.
- Start using the drawing application and ShaKey in Scratch!