pxt-microbit/docs/projects/v2-clap-lights.md

micro:bit target for Microsoft MakeCode (PXT)

# Clap Lights

## {Introduction @unplugged}

The new @boardname@s have a microphone to help them detect sound 🎤

Let's learn how to use a clap 👏 to switch your @boardname@'s lights on and off!

![Clap lights banner message](/static/mb/projects/clap-lights.png)

## {Setting up the sound input}

■ From the ``||input:Input||`` category, find the ``||input:on [loud] sound||`` container and add it to your workspace.

```blocks
// @highlight
input.onSound(DetectedSound.Loud, function () {

})
```

## {Creating a lightsOn variable}

Let's begin by creating a [__*variable*__](#variable "a holder for information that may change") to keep track of whether the @boardname@'s lights are on or off.

■ In the ``||variables:Variables||`` category, click on ``Make a Variable...`` and make a variable named ``lightsOn``.

## {Displaying LEDs part 1}

In this step, we'll be using an [__*if then / else*__](#ifthenelse "runs some code if a Boolean condition is true and different code if the condition is false") statement.

■ From the ``||logic:Logic||`` category, grab an ``||logic:if <true> then / else||`` block and snap it into your ``||input(noclick):on [loud] sound||`` container.  
■ Look in the ``||variables:Variables||`` category. Find the new ``||variables:lightsOn||`` variable and snap it in to **replace** the ``||logic(noclick):<true>||`` value in your ``||logic(noclick):if <true> then / else||`` statement.

```blocks
let lightsOn = 0
input.onSound(DetectedSound.Loud, function () {
    // @highlight
    if (lightsOn) {
    	
    } else {
    	
    }
})
```

## {Displaying LEDs part 2}

■ From ``||basic:Basic||``, grab ``||basic:show leds||`` and snap it into the **top container** of your ``||logic(noclick):if then / else||`` statement.  
■ Set the lights to a pattern you like!  
💡 In the hint, we chose to turn on all of the outside lights. Feel free to make your own design 🎨

```blocks
let lightsOn = 0
input.onSound(DetectedSound.Loud, function () {
    if (lightsOn) {
        // @highlight
    	basic.showLeds(`
            # # # # #
            # . . . #
            # . . . #
            # . . . #
            # # # # #
            `)
    } else {
    }
})
```

## {Clearing the screen}

■ From ``||basic:Basic||``, find ``||basic:clear screen||`` and snap it into the **bottom container** of your ``||logic(noclick):if then / else||`` section.  
💡 This will turn the display off if ``lightsOn`` is **not** ``true``.

```blocks
let lightsOn = 0
input.onSound(DetectedSound.Loud, function () {
    if (lightsOn) {
    	basic.showLeds(`
            # # # # #
            # . . . #
            # . . . #
            # . . . #
            # # # # #
            `)
    } else {
        // @highlight
    	basic.clearScreen()
    }
})
```

## {Setting the lightsOn variable}

Just like we'd toggle a light switch, each time we clap, we want to **flip** the variable ``lightsOn`` to the **opposite** of what it was before.

■ From ``||variables:Variables||``, locate ``||variables:set [lightsOn] to [0]||`` and snap it in at the **very top** of your ``||input(noclick):on [loud] sound||`` container.  
■ From the ``||logic:Logic||`` category, find the ``||logic:not <>||`` operator and use it to **replace the ``[0]``** in ``||variables(noclick):set [lightsOn] to [0]||``.  
■ From ``||variables:Variables||``, grab ``||variables:lightsOn||`` and snap it into the **empty part** of the ``||logic(noclick):not <>||`` operator.

```blocks
let lightsOn = false
input.onSound(DetectedSound.Loud, function () {
    // @highlight
    lightsOn = !(lightsOn)
    if (lightsOn) {
    	basic.showLeds(`
            # # # # #
            # . . . #
            # . . . #
            # . . . #
            # # # # #
            `)
    } else {
    	basic.clearScreen()
    }
})
```

## {Testing in the simulator}

■ Check out the simulator!  
■ Click on the pink slider bar beneath the microphone icon and drag it up and down.  
💡 Right now, your @boardname@ thinks that anything above 128 is loud. Every time the sound goes > 128, your lights should switch on/off.

## {Set loud sound threshold}

Your @boardname@ might detect sounds when you don't want it to. Setting a [__*sound threshold*__](#soundThreshold "a number for how loud a sound needs to be to trigger an event. 0 = silence to 255 = maximum noise") could help 🔉🔊

■ Click on the ``||input:Input||`` category. A new category should show up beneath it called ``||input:...more||``.  
■ From ``||input:...more||``, grab ``||input:set [loud] sound threshold to [128]||`` and snap it into your **empty** ``||basic(noclick):on start||`` container.  
💡 Try to change the value of your sound threshold so that every time you clap, your lights will turn on if they are off and vice versa.

```blocks
// @highlight
input.setSoundThreshold(SoundThreshold.Loud, 150)
```

## {Testing, round 2}

Don't forget to test your code in the simulator!

If you have a new @boardname@ (the one with the **shiny gold** logo at the top), download this code and try it out!

```blocks
let lightsOn = false
input.onSound(DetectedSound.Loud, function () {
    lightsOn = !(lightsOn)
    if (lightsOn) {
    	basic.showLeds(`
            # # # # #
            # . . . #
            # . . . #
            # . . . #
            # # # # #
            `)
    } else {
    	basic.clearScreen()
    }
})
input.setSoundThreshold(SoundThreshold.Loud, 150)
```

```validation.global
# BlocksExistValidator
```

```template
//
```