pxt-calliope/docs/projects/turtle-spiral.md

Turtle Spiral

Setting up your project

This project uses an microturtle Extension. You'll need to add it to your project to make it work.

• create a new project
• click on the gearwheel menu and click Extensions
• select the microturtle extension

After the project reloads, you should see the turtle category in the blocks.

Code

A turtle that spirals into the center of the display and back out again.

let index = 0
turtle.setPosition(0, 0)
turtle.turnRight()
basic.forever(() => {
    for (let index = 0; index <= 4; index++) {
        turtle.forward(4 - index)
        turtle.turnRight()
    }
    for (let index = 0; index <= 4; index++) {
        turtle.turnLeft()
        turtle.back(index)
    }
})

microturtle=github:Microsoft/pxt-microturtle#master