Examples

Play a melody on a buzzer

Pitches and lengths live in arrays and are played in order.

Arduino Uno R30 libraries56 linesOverall confidence 100%

SourceRead onlydigital_tone_melody.ino

/* Melody Plays a melody circuit: - 8 ohm speaker on digital pin 8 created 21 Jan 2010 modified 30 Aug 2011 by Tom Igoe This example code is in the public domain. https://docs.arduino.cc/built-in-examples/digital/toneMelody/ */ // pitches.h merged in: this playground compiles a single file. Only the notes this sketch // uses are here; the full table is at https://docs.arduino.cc/built-in-examples/digital/toneMelody/ #define NOTE_A3 220 #define NOTE_B3 247 #define NOTE_C4 262 #define NOTE_G3 196 // notes in the melody: int melody[] = { NOTE_C4, NOTE_G3, NOTE_G3, NOTE_A3, NOTE_G3, 0, NOTE_B3, NOTE_C4 }; // note durations: 4 = quarter note, 8 = eighth note, etc.: int noteDurations[] = { 4, 8, 8, 4, 4, 4, 4, 4 }; void setup() { // iterate over the notes of the melody: for (int thisNote = 0; thisNote < 8; thisNote++) { // to calculate the note duration, take one second divided by the note type. //e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc. int noteDuration = 1000 / noteDurations[thisNote]; tone(8, melody[thisNote], noteDuration); // to distinguish the notes, set a minimum time between them. // the note's duration + 30% seems to work well: int pauseBetweenNotes = noteDuration * 1.30; delay(pauseBetweenNotes); // stop the tone playing: noTone(8); } } void loop() { // no need to repeat the melody. }

What the parser saw

Extracted from #include · #define · pinMode · constructor arguments. The output of a deterministic parser, not an AI.

Parts

buzzertone(8,

80%

Buses

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Libraries

No libraries — read from pin names and pinMode alone.

Pin contract

An immutable contract owned by the project. It survives level changes; on a target board only the physical pins are remapped.

Logical name	Pin	Direction	Signal	Declared as
8	D8	out	pwm	literal

This page passes no verification gate. Logic (simulator), electrical (ERC · DRC) and physical (your confirmation) verification each run separately inside a project.

Next step

Same sketch, from simulation to PCB

The code stays as it is. Run it on avr8js in the Playground; import it into a project and the 8-pass electrical verification, KiCad board generation and Gerber export follow.

Run in Playground Import into a project