pxt-calliope/docs/projects/banana-keyboard-challenges.md

banana keyboard blocks challenges

control images with variables.

Before we get started

Control images with variables.

Have you ever tried to making beat box sounds? Let's try making a beatbox with code!

We will register an event handler on the fruit that will execute when two things occur: first, the alligator clip attaches to GND and the other side of the alligator clip is inserted into a banana. Let's start by adding a variable where you can store data. Then rename the variable to "sound". Then set the value of the variable to the note block A from the Music drawer. Modify your code so that your code looks like this.

let sound = music.noteFrequency(Note.A);

We want to play music on pin pressed in order to register an event handler that will execute whenever when you run a script and click pin 1 on the simulator. We must start by opening the Input drawer and adding on pin pressed P1. Modify your code so that your code looks like this.

let sound = music.noteFrequency(Note.A);
input.onPinPressed(TouchPin.P1, () => {

})

We want to code the notes that will be played on pin pressed. We click on the Input drawer then insert a for loop that will increment by i. Click on the Variables drawer. Add set item block. Rename the variable block to "sound." Then add a Maths block to increase the variable sound from the note frequency of block A to A plus 25.Modify your code so that your code looks like this

let sound = music.noteFrequency(Note.A);
input.onPinPressed(TouchPin.P1, () => {
    for (let i = 0; i < 4; i++) {
        sound = sound + 25
    }
})

• click run to see if the code works as expected.

Let's include a second sound on pin pressed P2. To do this, you need to add the same blocks as the banana keyboard activity. However, you must change alter on pin pressed from P1 to P2. Additionally, you must decrease the frequency of the variable "sound" by 25. Modify your code so that your code looks like this. You will need to include a second banana to a alligator (spring) clip in the same procedure as the first activity.

let sound = music.noteFrequency(Note.A);

input.onPinPressed(TouchPin.P1, () => {
    for (let i = 0; i < 4; i++) {
        sound = sound + 25
    }
})

input.onPinPressed(TouchPin.P2, () => {
    for (let i = 0; i < 4; i++) {
        sound = sound - 25
    }
})

• click run to see if the code works as expected.

~button /projects/telegraph

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