Arduino project · Sound and music · Medium
Keypad Piano
Keys 1 to 8 play the notes C, D, E, F, G, A, B and the high C.
What you will learn
- How each musical note has a frequency in Hz
- How tone() makes sound on a passive buzzer
- How a key chooses a note
How it works
Each key writes a frequency to the buzzer. 262 Hz is middle C, and each key moves up the scale. When no key is held the tone is switched off.
Try this next
- Add keys 9, 0 and * for more notes.
- Add an LED that flashes with each note.
- Record a tune and play it back.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A speaker and a piano
The speaker plays the note your program picks. The piano keys light up so you can see which note it is, and the rings show the sound waves.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- Passive buzzer = the speaker and its note
- Input = what changes the pitch