pxt-ev3/docs/maker/sound-machine.md

Make a Sound Machine

Make a Sound Machine that can play a rhythm, music or just noise!

Connect

Music is made up of a combination of sounds, notes and rhythm. A rhythm is a regular movement or repeated pattern of movements that can be used in many different ways. In mechanical machines, a rhythm can help keep a machine running smoothly. It can also be used to generate different sounds in music.

Look at the photos and think about:

• What do you see?
• Can you see any new design opportunities?
• What problems can you see?
• How could you make use of the LEGO bricks, the EV3 Programmable Brick, motors, and sensors?

Things You’ll Need

• @boardname@ Core Set

Additional materials to add to your Sound Machine:

• Small musical instruments, such as chimes, bells, and small drums
• Arts and crafts materials such as:

• Cardboard
• Construction paper
• Pipe cleaners
• Plastic or paper cups
• Recycled materials
• Rubber bands
• Wire

Prior Knowledge

This activity uses motor rotations and sensor inputs. You may want to try the Use or Object Detection activity before this one. Or, you can start out with this activity and tinker with coding motor and sensor inputs on your own.

Contemplate

Follow the steps of the Maker Design Process for this lesson:

	Define the Problem
	Brainstorming
	Define the Design Criteria
	Go Make
	Review and Revise Your Solution
	Communicate Your Solution

Defining the Problem

1. What problems did you imagine?
2. Pick one problem and explain it to a partner.

Brainstorm

Now that you have defined a problem, start to generate ideas for solving it.

~hint

Some things to do while brainstorming:

• Use the bricks from the LEGO set to help you brainstorm or sketch your ideas on paper.
• The goal of brainstorming is to explore as many solutions as possible. You can use the tinkering examples in the Sample Solutions section below as inspiration for getting started.
• Share your ideas and get some feedback. It may lead to more ideas!

~

Define the Design Criteria

• You should have generated a number of ideas. Now select the best one to make.
• Write out two or three specific design criteria your design must meet.

Go Make

It is time to start making!

• Use the components from the @boardname@ Core Set and additional materials to make your chosen solution.
• Test and analyze your design as you go and record any improvements that you make.

Review and Revise Your Solution

• Have you managed to solve the problem that you defined?
• Look back at your design criteria. How well does your solution work?
• How can you improve your design?

Communicate Your Solution

Now that you have finished you can:

• Make a sketch or take a photo or video of your model.
• Label the three most important parts and explain how they work.
• Share your work with others.

Continue

Rhythm Maker - Sample Solution

This example program combined with the small model will make a beat and rhythm on any surface when the program is run.

Programming

1. Drag a run ||motors:large motor A|| block inside the ||loops:forever|| loop.
2. Press the (+).
3. Change the rotations to 2.
4. Drag a ||loops:pause|| block and place it under the motor block.
5. Change the duration to 200 ms.
6. Drag a ||run large motor A|| block inside the ||loops:forever|| loop.
7. Press the (+).
8. Change the power to 100.
9. Change the rotations to 1.

forever(function () {
    motors.largeA.run(50, 2, MoveUnit.Rotations)
    pause(200)
    motors.largeA.run(100, 1, MoveUnit.Rotations)
})

Click Download and follow the instructions to get your code onto your EV3 Brick. Press the center button on the EV3 Brick to run the program.

Color Sensor Sounds - Sample Solution

You can also tinker with the use of sensors.

Programming

1. Drag an ||logic:if else|| Logic block and place it inside the ||loops:forever|| loop.
2. Drag a ||sensors:pause color sensor|| block and place it inside the ||logic:if true then|| block.
3. Change the color to blue.
4. Drag a ||music:play tone|| block and place under the sensor block.
5. Change the tone to Middle G (392 Hz).
6. Drag a ||sensors:pause color sensor|| block and place it inside the ||logic:else|| block.
7. Change the color to red.
8. Drag a ||music:play tone|| block and place under the new sensor block.
9. Change the tone to High C (523 Hz).
10. Press the (+).
11. Drag a ||sensors:pause color sensor|| block and place it inside the ||logic:else if|| block.
12. Change the color to green.
13. Drag a ||music:play tone|| block and place under the new sensor block.
14. Change the tone to High D (587 Hz).

forever(function () {
    if (true) {
        sensors.color3.pauseUntilColorDetected(ColorSensorColor.Blue)
        music.playTone(392, music.beat(BeatFraction.Whole))
    } else if (false) {
        sensors.color3.pauseUntilColorDetected(ColorSensorColor.Red)
        music.playTone(523, music.beat(BeatFraction.Half))
    } else {
        sensors.color3.pauseUntilColorDetected(ColorSensorColor.Green)
        music.playTone(587, music.beat(BeatFraction.Half))
    }
})

Click Download and follow the instructions to get your code onto your EV3 Brick. Press the center button on the EV3 Brick to run the program.