Move with the controller

Classroom resources

Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.

• Slides Download Copy address for Prepare Present from the browser, or export to PowerPoint or PDF.
• Worksheet Download Copy address for Prepare Print the student copy; the Teacher edition has the answers.

Students will be able to

• I can let the player steer a sprite with the arrow keys.
• I can choose which way a sprite can move, and how fast.
• I can keep a sprite on the screen.

Timing

Predict and Run 7 min · Investigate 10 min · Modify 10 min · Make 8 min · Goalkeeper 5 min

Before class

move with buttons (Controller) hands a sprite to the arrow keys: it moves while a key is held. Its two numbers (click + to show them) are the speeds across and up and down, in pixels per second; 0 stops movement that way. They are not a position. on A button pressed is an event: it runs each time A (space or Z) is pressed. Students must click the simulator before it hears keys.

Running the lesson

1. Predict: some students read the numbers as a place (100, 0). Ask what happens while a key is held.
2. Run: all four arrows. Up and down do nothing.
3. Investigate: Kim's cloud shows that the block steers only the sprite it names.
4. Modify: the dash changes x by 30: a position change, once per press.
5. Make: speeds 100 and 0, plus stay in screen.

In class

On the slides at these points. Students can do the whole lesson on their own; these are for the room. In the deck, the Run, Modify and Make slides have the live playground in them (the tutorial link is the backup), and the notes above are in each slide's speaker notes.

• Remote control (investigate, 4 min)

  One student is the sprite. The class holds up cards: across speed and up-down speed. The 'remote' presses arrows; the sprite moves only the ways its speeds allow.

  A speed card of 0 means that direction is locked.

• Escape test (end, 3 min)

  Swap ships with the next pair. Can theirs leave the screen?

The hard part (on purpose)

Reading the two numbers as speeds, not a place. Ask what each number does while a key is held.

When students get stuck

Answers to the checks

1. Predict: The plane has move with buttons with speeds 100 and 0. You hold the up arrow. What happens?
   Nothing. The second number is the speed up and down, and it is 0, so up and down do nothing. The numbers are speeds, not a place.
2. What does it do?: Match each block with what it does to a sprite.
   move with buttons → B. lets the arrow keys steer it, while a key is held; set stay in screen → C. stops it at the edge of the screen; set position → A. puts it at one place, once; on A button pressed → D. runs its blocks each time A is pressed
3. Which way is faster?: A sprite has move with buttons with speeds 50 and 100. Which way does it move faster?
   Up and down
   The first number (50) is the speed across, the second (100) the speed up and down. 100 is faster.
4. Kim's cloud: Kim's arrow keys move the cloud, not her plane. What did she do?
   Her move with buttons block names the cloud
   move with buttons steers only the sprite it names. Click the sprite's name in the block and choose plane.

Solutions

One possible solution for each task. Other correct programs are fine.

Modify › Only across

scene.setBackgroundColor(9)
let plane = sprites.create(img`
    . . . . 2 . . .
    2 . . . 2 2 . .
    2 2 1 1 1 1 1 2
    2 . . . 2 2 . .
    . . . . 2 . . .
    `, SpriteKind.Player)
plane.setPosition(20, 60)
controller.moveSprite(plane, 100, 0)

Modify › Dash

scene.setBackgroundColor(9)
let plane = sprites.create(img`
    . . . . 2 . . .
    2 . . . 2 2 . .
    2 2 1 1 1 1 1 2
    2 . . . 2 2 . .
    . . . . 2 . . .
    `, SpriteKind.Player)
plane.setPosition(20, 60)
controller.moveSprite(plane, 100, 0)
controller.A.onEvent(ControllerButtonEvent.Pressed, function () {
    plane.x += 30
})

Make

scene.setBackgroundColor(15)
let ship = sprites.create(img`
    . . 1 . .
    . 1 1 1 .
    1 1 1 1 1
    `, SpriteKind.Player)
ship.setPosition(80, 105)
controller.moveSprite(ship, 100, 0)
ship.setStayInScreen(true)

Change a goalkeeper

Open task: any program that does what the step asks.

Stretch and support

Stretch: Make A dash right and B dash left, and make the ship faster across than the plane was.

Support: Give students the ship with move with buttons already in, and ask them only to set the two speeds and keep it on the screen.

Exit ticket

move with buttons has speeds 0 and 80. Which arrow keys do something?

Only up and down. The first number, the speed across, is 0.

What each step is for

• Investigate: move with buttons links the arrow keys to one sprite, and its two numbers are its speeds across and down: a speed of 0 means it cannot move that way.
• Modify: The two numbers set which way the player can move, and how fast. A position change in an event moves a sprite once per press.

Where it leads

Next lesson: a speed the engine applies by itself, so a sprite keeps moving with nobody pressing anything.