pxt-microbit
Version:
micro:bit target for Microsoft MakeCode (PXT)
218 lines (176 loc) • 5.75 kB
Markdown
# Karel the LED
## ~avatar avatar
Help Karel make LED art!
## ~
**Karel the LED** can't turn right, but he can make some great LED art!
The goal of this activity is to download the JavaScript code given below onto a @.
Then use the program to introduce new students to the @.
Students will not do the coding this time. They will be the users who get familiar with the board.
## How to play
* ``A button`` **Turn Left**
>Does not draw anything just changes the direction Karel (the flashing led) is facing
* ``B button`` **Move Forward**
>Moves Karel forward one step and leaves the LED on behind him
* ``shake`` **Jump**
>Moves Karel forward one step without leaving the LED on behind him
* ``A+B button`` **Hide Karel**
>Shows or hides Karel (the flashing LED), to be used once your artwork is complete
* ``Reset button`` **Clear the board and restart**
>Restart the program and clear the board
**Note:** There is no way to erase, except by restarting.
## Try drawing some patterns
See if you can make each pattern below using **A**, **B**, and **shake**. Once you have completed a challenge press **A** and **B** at the same time to hide Karel.
For patterns that you design, decide which LEDs you want to turn on and then make that design with Karel.
### Spiral
### Right turn
### Eyes
### Smile
### Check
### First letter of your name
Figure out how to make the first letter of your name with the LEDs.
```sim
basic.forever(function () {
basic.showAnimation(`
# # # . . # # # . . # # # . . # # # . .
. . . . . # . . . . # . . . . # . . # .
. . . . . # . . . . # . . . . # . . # .
. . . . . # . . . . # . . . . # . . # .
. . . . . # . . . . # # # . . # # # . .
`)
basic.pause(1000)
basic.clearScreen()
basic.pause(1000)
})
```
### Your design!
Make something fun!
```sim
basic.forever(function () {
basic.showAnimation(`
# . . . . # . . . . # . . . . # . . . . # . . . . # . . . .
. . . . . # . . . . # . . . . # . . . . # . . . # # . # # #
. . . . . # . . . . # . . . . # . . . . # . . . # # . # . #
. . . . . # . . . . # . . . . # . . . . # . . . # # . . . #
. . . . . # . . . . # # # # # # # # # # # # # # # # # # # #
`)
basic.pause(1000)
basic.clearScreen()
basic.pause(1000)
})
```
Thanks for playing with Karel the LED!
## Coding Karel the LED
Copy this code into the JavaScript editor and then download it to the board.
**Note:** For this project you need to manually copy the code and insert it into the JavaScript view of the editor.
```typescript
class Board {
public isKarelActive: boolean
public karelX: number
public karelY: number
public ledState: Image
private karelDirection: Direction
constructor() {
this.isKarelActive = true
this.karelX = 2
this.karelY = 2
this.karelDirection = Direction.UP
this.ledState = images.createImage(`
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
`)
}
pressedA() {
if (!this.isKarelActive) {
return
}
this.karelDirection = (this.karelDirection + 1) % 4
}
pressedB() {
if (!this.isKarelActive) {
return
}
this.ledState.setPixel(this.karelX, this.karelY, true)
this.moveKarel()
}
shake() {
if (!this.isKarelActive) {
return
}
this.moveKarel()
}
private moveKarel() {
if (!this.isKarelActive) {
return
}
switch (this.karelDirection) {
case Direction.UP:
if (this.karelY > 0) {
this.karelY -= 1
}
break
case Direction.LEFT:
if (this.karelX > 0) {
this.karelX -= 1
}
break
case Direction.DOWN:
if (this.karelY < 4) {
this.karelY += 1
}
break
case Direction.RIGHT:
if (this.karelX < 4) {
this.karelX += 1
}
break
}
}
pressedAB() {
this.isKarelActive = !this.isKarelActive
}
update() {
this.ledState.showImage(0)
}
}
const board = new Board()
enum Direction {
UP = 0,
LEFT,
DOWN,
RIGHT
}
input.onButtonPressed(Button.B, function () {
board.pressedB()
board.update()
})
input.onGesture(Gesture.Shake, function () {
board.shake()
board.update()
})
input.onButtonPressed(Button.A, function () {
board.pressedA()
board.update()
})
input.onButtonPressed(Button.AB, function () {
board.pressedAB()
board.update()
})
basic.forever(function () {
if (board.isKarelActive) {
led.toggle(board.karelX, board.karelY)
basic.pause(500)
}
})
```
## About the authors
This project\*\* was contributed by Dr. David Fisher a professor at [Rose-Hulman Institute of Technology](https://www.rose-hulman.edu/academics/faculty/fisher-david-fisherds.html). Dr. Fisher loves educational robotics and runs various outreach programming activities, including a summer camp, called [Connecting with Code](https://connectingwithcode.org), which gives a @boardname@ to each participant.
\*\* Upgraded to **v1** by the MakeCode team.