pxt-calliope/docs/projects/multi-dice.md

Multi Dice

Introduction @unplugged

Build a multi-player dice game using the radio. The radio blocks let you send wireless messages between a @boardname@ and another @boardname@.

In this game, you shake to "throw the dice" and send the result to the other @boardname@. If you receive a result of a dice throw equal or greater than yours, you lose.

Dice game @fullscreen

Let's start by rebuilding the dice game. If you are unsure about the details, try the dice tutorial again.

input.onGesture(Gesture.Shake, function () {
    basic.showNumber(Math.randomRange(1, 6))
})

Dice variable @fullscreen

We need to store the result of the dice cast in a variable. A variable is like a place in the memory of the @boardname@ where you save information, like numbers.

• Go to the Variables toolbox and click ||Make a Variable|| to create a new variable. We will call it dice.
• Add a ||set dice to|| block and drag the ||pick random|| into it.
• Drag a ||dice|| from the Variables toolbox into the ||basic:show number|| block.

let dice = 0
input.onGesture(Gesture.Shake, function () {
    dice = Math.randomRange(1, 6)
    basic.showNumber(dice)
})

Send the dice @fullscreen

Put in a ||radio:send number|| and a ||dice|| to send the value stored in the dice variable via radio.

let dice = 0
input.onGesture(Gesture.Shake, function () {
    dice = Math.randomRange(1, 6)
    basic.showNumber(dice)
    radio.sendNumber(dice)
})

Receive the dice @fullscreen

Go get an ||radio:on received number|| event block. This event runs when a radio message from another @boardname@ arrives. The receivedNumber value is the value of the dice in this game.

radio.onReceivedNumber(function (receivedNumber) {
})

Check your cast @fullscreen

Add a ||logic:if|| block to test if receivedNumber is greater or equal to dice. If is, you lost so display a sad face on the screen.

let dice = 0;
radio.onReceivedNumber(function (receivedNumber) {
    if (receivedNumber >= dice) {
        basic.showIcon(IconNames.Sad)
    }
})

Test it! @fullscreen

Try pressing SHAKE in the simulator and see that a second @boardname@ appears. You can play the game on both virtual boards.

If you have more than one @boardname@, download your code onto each one and try playing the game with your friends!

let dice = 0
input.onGesture(Gesture.Shake, function () {
    dice = Math.randomRange(1, 6)
    basic.showNumber(dice)
    radio.sendNumber(dice)
})
radio.onReceivedNumber(function (receivedNumber) {
    if (receivedNumber >= dice) {
        basic.showIcon(IconNames.Sad)
    }
})

radio