MakerKid Easy Kit: Mini Piano

Welcome to MakerKit Kits! today you will be building a Mini Piano.

This is an Easy kit version so no soldering. it is for people who want to get into building cool and fun electronic devices.

We will be talking about all the parts so don't worry if you don't know what everything does. you will understand what they all do by the end of building this kit!

Supplies

All the parts you need are in your kit:

You will have:

1 Arduino nano - The brain of the piano

1 Custom PCB with buttons, buzzer and resistor soldered on - A circuit board that holds all your parts on it

1 USB-C cable - A cable that connects with your computer to upload code or give power

8 Screws - For screwing your piano together

8 Button keys - The keys of your piano

1 bottom part of case - A 3D printed bottom part of your case that sits on the bottom

1 top part of case - A 3D printed top part of your case that sits on the bottom case

Materials:

You will need:

1 Hex 2 allen key or screwdriver

A computer (optional only if you want to change the code)

How Does the Circuit Work?

The Mini Piano circuit works by the Arduino Nano sensing each of the buttons, then when a button gets hit it signals the Arduino Nano to send a signal to the piezo buzzer and then it plays at that frequency playing C, D, E, F, G, A, or B based on what pin the button was connected to.

How Does a PCB Work?

A PCB (Printed Circuit Board) is a flat board that holds all your electronic parts for your project in the right place. Instead of lots of wires, a PCB has thin copper lines printed inside it that connect everything together. When you plug or solder parts onto the PCB, power and signals travel through those copper paths to make your circuit work.

How Does an Arduino Nano Work?

An Arduino Nano works because of its main chip (usually an ATmega328P) is a tiny computer that runs your uploaded code from its memory. When it powers on it runs your code and in your code it will run setup() once, then repeats loop() forever, always reading voltages on its input pins and switching its output pins from HIGH/LOW (or PWM) to control things like LEDs, motors, and buzzers.

How Does a Piezo Buzzer Work ?

A piezo buzzer uses a ceramic disc that bends when voltage changes, causing it to vibrate. Those vibrations move the air and make sound, and the pitch depends on how fast you toggle the voltage (frequency).

How Does a Resistor Work?

A banded resistor uses colored stripes to encode its resistance value and tolerance; you read the first bands as digits, the next as the multiplier, and the last as the tolerance. If you add +1 Ω, you simply increase the final resistance by one ohm (e.g., 220 Ω becomes 221 Ω).

Placing Arduino Nano Onto PCB

time to start building! place your Arduino nano into its spot and push down until snug. Make sure that it is the right way the USB plug is facing out.

Screwing the PCB Into the Case

Grab a screwdriver with a Hex 2 bit and 4 of your screws. Place the PCB onto the bottom case. Make sure that the Arduino Nano is facing to the outside, and the piezo buzzer is in its spot.

Putting Button Keys Into Top Case

get all of your button keys and your top case ready, then make sure that the flat side is facing down when you put the buttons in.

Placing Bottom Case Into Top Case

take your top and bottom case make sure that your buttons keys dont fall out! now flip your bottom case upside down and make sure the buttons are going inside the buttons keys. then tilt the bottom case towards you and get the PCB underneath the screw pillars on the top case. Now push it all together.

Screwing Case Together

Grab your last four screws and your screwdriver and flip over you piano, then screw in all four of the screws. Make sure that the screws are strait when you screw them in.

The Code

Screenshot 2025-12-22 at 12.41.31 PM.png

The Arduino Nano already has code uploaded onto it so it will work right when you plug it all in. But if you want to change it to make some cool upgrades go ahead!

To upload your code download and install Arduino IDE

then plug in your Arduino nano and copy and paste your code into Arduino IDE then hit upload.

// MakerKid Easy Kit: Mini Piano

// 7 buttons on D2–D8, piezo buzzer on D9 Arduino nano

// Hold a key to hold the note.

// If multiple keys are pressed, the highest note plays.

const int buzzerPin = 9;

// Buttons for notes C D E F G A B

const int buttonPins[7] = {2, 3, 4, 5, 6, 7, 8};

// Frequencies for notes C4 to B4 (Hz)

const int noteFreq[7] = {

262, // C

294, // D

330, // E

349, // F

392, // G

440, // A

494 // B

};

void setup() {

// Set all buttons with internal pullups

for (int i = 0; i < 7; i++) {

pinMode(buttonPins[i], INPUT_PULLUP);

}

pinMode(buzzerPin, OUTPUT);

}

void loop() {

int chosenFreq = 0;

// Check all keys.

// If more than one is pressed, the last one in the array (highest note)

// will be chosen.

for (int i = 0; i < 7; i++) {

int state = digitalRead(buttonPins[i]);

// Button pressed? (LOW because of INPUT_PULLUP)

if (state == LOW) {

chosenFreq = noteFreq[i];

}

if (chosenFreq > 0) {

// At least one key pressed: play that note

tone(buzzerPin, chosenFreq);

} else {

// No keys pressed: silence

noTone(buzzerPin);

}

delay(5); // tiny delay to smooth reading

}

Play the Piano!

time to play your piano! the piano has keys C, D, E, F, G, A, and B so you can play some simple songs! Have fun playing

Conclusion

We hope you had fun building our kit

(sorry I don't have the website up and running yet but I will soon :)

(I am hand soldering all the units right now so they might be short on stock but i will try my best to go as fast as I can :)

(we will also only be shipping to Canada)

THANKS FOR BUILDING!