4.5 KiB
Rock Paper Scissors
~avatar avatar
Build a Rock Paper Scissors game with the BBC micro:bit! You can play the game with a friend who has it on a micro:bit. You can also play it with friends who are just using their hands. (The game is built like a coin flipper, but with three choices instead of two.)
~
Step 1: Getting started
We want the micro:bit to choose rock, paper, or scissors when you
shake it. Try creating an on shake block so when you shake the
micro:bit, it will run part of a program.
Clear up the blocks and add the blocks below.
input.onGesture(Gesture.Shake, () => {
})
Next, when you shake the micro:bit, it should pick a random number from 0 to 2
and store it in the variable item.
Add a set block with a variable. Then add a pick random block,
and store the random number in the variable,
like this:
input.onGesture(Gesture.Shake, () => {
let item = Math.random(3)
})
~hint
No one can predict random numbers. That's what makes them great for Rock Paper Scissors!
~
Each possible number these blocks can make (0, 1, or 2) means a different picture.
We will show the right picture for that number on the LED screen.
Step 2: Picking paper
Put an if block after the let block that checks whether
item is 0. Make sure the if block has an else if part
and an else part.
Next, add a show leds block that shows a
picture of a piece of paper:
input.onGesture(Gesture.Shake, () => {
let item = Math.random(3)
if (item == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (false) {
} else {
}
})
Step 3: A random rock
Now we are going to add a new picture for the micro:bit to show when another random number comes up.
Make the else if part check if the variable item is 1.
Then add a show leds block with a picture of a rock.
input.onGesture(Gesture.Shake, () => {
let item = Math.random(3)
if (item == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (item == 1) {
basic.showLeds(`
. . . . .
. # # # .
. # # # .
. # # # .
. . . . .
`)
} else {
}
})
Step 4: Suddenly scissors
Add a show leds block with a picture of scissors to the else part:
input.onGesture(Gesture.Shake, () => {
let item = Math.random(3)
if (item == 0) {
basic.showLeds(`
# # # # #
# . . . #
# . . . #
# . . . #
# # # # #
`)
} else if (item == 1) {
basic.showLeds(`
. . . . .
. # # # .
. # # # .
. # # # .
. . . . .
`)
} else {
basic.showLeds(`
# # . . #
# # . # .
. . # . .
# # . # .
# # . . #
`)
}
})
~hint
You don't need to check if item is 2 because 2 is the only number left out of 0, 1, and 2.
That's why you can use an else instead of an else if.
~
Your game is ready!
Click Compile to move your program to the BBC micro:bit!
Have fun!
Step 5: Are you the greatest?
Here is a way you can make your Rock Paper Scissors game better.
When button A is pressed,
the micro:bit will add 1 to your score.
Open the Game drawer, and then add the block change score by 1 to your program,
like this:
input.onButtonPressed(Button.A, () => {
game.addScore(1)
})
Step 6: Prove you're the greatest!
After your micro:bit can add 1 to the score, show how many wins you have.
input.onButtonPressed(Button.A, () => {
game.addScore(1)
basic.showString("WINS:")
basic.showNumber(game.score())
})
Step 7: Staying honest
Success! Your micro:bit can track wins!
But what about losses?
Use the Game drawer to subtract 1 from your score when you press button B.
Here are all the blocks you will need:
input.onButtonPressed(Button.B, () => {
game.addScore(-1)
basic.showString("LOSSES:")
basic.showNumber(game.score())
})
Click Compile to move your program to the BBC micro:bit!