pxt-calliope/docs/reference/js/lessons/screen-wipe/activity.md

screen wipe activity

Clear the screen by pressing buttons on the BBC micro:bit.

~avatar avatar

@video td/videos/screen-wipe-0

This activity will teach how to clear the screen by pressing button A on the BBC micro:bit.

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You can use the basic->clear screen function to turn off all the LED on the screen. Let's illustrate this concept with a small script where the user has to press the button A to turn off the screen. Let's start by adding the code to show an animation.

basic.showAnimation(`
# # # # # # # # # # . . . . . . . . . .
# # # # # # # # # # . . . . . . . . . .
. . . . . # # # # # # # # # # . . . . .
. . . . . # # # # # # # # # # # # # # #
. . . . . . . . . . . . . . . # # # # #
`, 400) // ***

We add another line of code that registers an event handler on the input->on button pressed(A) and calls basic->clear screen.

basic.showAnimation(`
# # # # # # # # # # . . . . . . . . . .
# # # # # # # # # # . . . . . . . . . .
. . . . . # # # # # # # # # # . . . . .
. . . . . # # # # # # # # # # # # # # #
. . . . . . . . . . . . . . . # # # # #
`, 400)
input.onButtonPressed(Button.A, () => {
    basic.clearScreen() // ***
}) // ***

Run the script in the simulator or on the BBC micro:bit to see how this works!

~avatar boothing

Excellent, you're ready to continue with the challenges!

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