Examples

Turn an LED on while a button is held

D13 lights only while the button is pressed.

Arduino Uno R30 libraries52 linesOverall confidence 100%

SourceRead onlydigital_button.ino

/* Button Turns on and off a light emitting diode(LED) connected to digital pin 13, when pressing a pushbutton attached to pin 2. The circuit: - LED attached from pin 13 to ground through 220 ohm resistor - pushbutton attached to pin 2 from +5V - 10K resistor attached to pin 2 from ground - Note: on most Arduinos there is already an LED on the board attached to pin 13. created 2005 by DojoDave <http://www.0j0.org> modified 30 Aug 2011 by Tom Igoe This example code is in the public domain. https://docs.arduino.cc/built-in-examples/digital/Button/ */ // constants won't change. They're used here to set pin numbers: const int buttonPin = 2; // the number of the pushbutton pin const int ledPin = 13; // the number of the LED pin // variables will change: int buttonState = 0; // variable for reading the pushbutton status void setup() { // initialize the LED pin as an output: pinMode(ledPin, OUTPUT); // initialize the pushbutton pin as an input: pinMode(buttonPin, INPUT); } void loop() { // read the state of the pushbutton value: buttonState = digitalRead(buttonPin); // check if the pushbutton is pressed. If it is, the buttonState is HIGH: if (buttonState == HIGH) { // turn LED on: digitalWrite(ledPin, HIGH); } else { // turn LED off: digitalWrite(ledPin, LOW); } }

What the parser saw

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

Parts

ledidentifier ledPin

60%

buttonidentifier buttonPin

60%

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
buttonPin	D2	in	digital	#define
ledPin	D13	out	digital	#define

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