pxt-calliope/docs/lessons/rotation-animation/challenges.md
2016-03-28 15:06:52 -07:00

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# rotation animation block challenges
Coding challenges for the rotation animation.
## Before we get started
Complete the following guided activity:
* [activity](/microbit/lessons/rotation-animation/activity)
At the end of the activity, your code should look like this:
```blocks
let rotating = true;
while (rotating) {
basic.pause(20)
basic.showLeds(`
# . . . .
. # . . .
. . # . .
. . . # .
. . . . #
`)
basic.showLeds(`
. . # . .
. . # . .
. . # . .
. . # . .
. . # . .
`)
basic.showLeds(`
. . . . #
. . . # .
. . # . .
. # . . .
# . . . .
`)
basic.showLeds(`
. . . . .
. . . . .
# # # # #
. . . . .
. . . . .
`)
}
```
### Challenge 1
Now let's add to this by creating a condition for on button pressed `A` before the while loop. We will also introduce serial writeLine for the while loop and input OnButtonPressed
```blocks
let rotating = true;
input.onButtonPressed(Button.A, () => {
serial.writeLine("hello")
})
while (rotating) {
serial.writeLine("loop")
basic.showLeds(`
# . . . .
. # . . .
. . # . .
. . . # .
. . . . #
`)
basic.showLeds(`
. . # . .
. . # . .
. . # . .
. . # . .
. . # . .
`)
basic.showLeds(`
. . . . #
. . . # .
. . # . .
. # . . .
# . . . .
`)
basic.showLeds(`
. . . . .
. . . . .
# # # # #
. . . . .
. . . . .
`)
}
```
### Challenge 2
### @video td/videos/rotation-animation-1-and-2
Now that we have the on button pressed condition, let's make the animation stop rotating by setting the rotating global variable to false when button `A` is pressed.
```blocks
let rotating = true;
input.onButtonPressed(Button.A, () => {
serial.writeLine("hello")
rotating = false
})
while (rotating) {
serial.writeLine("loop")
basic.showLeds(`
# . . . .
. # . . .
. . # . .
. . . # .
. . . . #
`)
basic.showLeds(`
. . # . .
. . # . .
. . # . .
. . # . .
. . # . .
`)
basic.showLeds(`
. . . . #
. . . # .
. . # . .
. # . . .
# . . . .
`)
basic.showLeds(`
. . . . .
. . . . .
# # # # #
. . . . .
. . . . .
`)
}
```
* Run the code to see the awesome rotation.
### Challenge 3
Let's also make the image rotate the opposite way when button A is pressed! We can do this with another while loop that is only executed while `not rotating`.