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OR Gate

A fundamental digital logic gate that outputs HIGH when at least one of its inputs is HIGH.

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OR Gate

A fundamental digital logic gate that implements logical disjunction. It produces a HIGH output if any of its inputs are HIGH. The output is LOW only when all inputs are LOW.

Logic ComponentsDigital Logic

Overview

The OR Gate evaluates multiple digital signals and returns true (HIGH) if any single condition is met. It is widely used in control logic, alarm systems, and conditional branching in digital circuits.

Pin Reference

Pin	Type	Description
IN1	input	First digital logic input. Expects HIGH (1) or LOW (0).
IN2	input	Second digital logic input. Expects HIGH (1) or LOW (0).
OUT	digital	Digital logic output. Driven HIGH if IN1 or IN2 is HIGH.

Configurable Attributes

This component currently has no configurable attributes.

Working Principle

Truth Table

IN1	IN2	OUT
0 (LOW)	0 (LOW)	0 (LOW)
0 (LOW)	1 (HIGH)	1 (HIGH)
1 (HIGH)	0 (LOW)	1 (HIGH)
1 (HIGH)	1 (HIGH)	1 (HIGH)

The OR Gate models Boolean addition (A + B = Y).

Wiring Diagram

Example of a logic OR gate wired to an Arduino Uno and an LED (with a resistor).

Example Arduino Code

const int pinIn1 = 2; // Connect to IN1
const int pinIn2 = 3; // Connect to IN2
const int pinOut = 4; // Connect to OUT

void setup() {
  Serial.begin(9600);
  pinMode(pinIn1, OUTPUT);
  pinMode(pinIn2, OUTPUT);
  pinMode(pinOut, INPUT);
  Serial.println("OR Gate Truth Table Test:");
}

void loop() {
  for (int state = 0; state < 4; state++) {
    bool val1 = (state & 1);
    bool val2 = (state & 2) >> 1;

    digitalWrite(pinIn1, val1 ? HIGH : LOW);
    digitalWrite(pinIn2, val2 ? HIGH : LOW);
    delay(10);
    
    int result = digitalRead(pinOut);
    
    Serial.print("IN1: ");
    Serial.print(val1);
    Serial.print(" | IN2: ");
    Serial.print(val2);
    Serial.print(" => OUT: ");
    Serial.println(result);
    delay(1000);
  }
}

Simulation Notes

• Evaluates logic instantaneously.
• Floating inputs may cause undefined behavior. Tie unused inputs to Ground.

Notes / Warnings

• Voltage Levels: The simulator treats standard logic signals as valid inputs. Do not apply analog voltages.

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