Arduino Nano Simulator: Architecture Breakdown & Circuit Guide

const int ledPin = 9; // PWM pin D9

void setup() {
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Nano Breathing Beacon Active");
}

void loop() {
  // Fade in from min to max in increments of 5
  for (int fadeValue = 0; fadeValue <= 255; fadeValue += 5) {
    analogWrite(ledPin, fadeValue);
    delay(25);
  }

  // Fade out from max to min in increments of 5
  for (int fadeValue = 255; fadeValue >= 0; fadeValue -= 5) {
    analogWrite(ledPin, fadeValue);
    delay(25);
  }
}

const int potPin = A0;
const int lightPin = A6; // Extra analog pin on Nano

void setup() {
  Serial.begin(9600);
  Serial.println("Nano Environmental Monitor Initialized");
}

void loop() {
  int knobValue = analogRead(potPin);    // 0 to 1023
  int lightLevel = analogRead(lightPin); // 0 to 1023

  Serial.print("Knob: ");
  Serial.print(knobValue);
  Serial.print(" | Ambient Light: ");
  Serial.println(lightLevel);

  delay(250);
}

const int buttonPin = 2;
const int buzzerPin = 8;

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);
  pinMode(buzzerPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Nano Sound Chime Ready. Press button to play sound.");
}

void loop() {
  int isPressed = (digitalRead(buttonPin) == LOW);

  if (isPressed) {
    Serial.println("Playing Chime Melody...");
    // Play two cheerful tones
    tone(buzzerPin, 1000, 150); // 1000Hz for 150ms
    delay(180);
    tone(buzzerPin, 1500, 200); // 1500Hz for 200ms
    delay(300);
  }
}

const int trigPin = 11;
const int echoPin = 12;
const int alertLed = 7;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(alertLed, OUTPUT);
  Serial.begin(9600);
  Serial.println("Nano Ultrasonic Sentinel Online");
}

void loop() {
  // Trigger ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure echo return time
  long duration = pulseIn(echoPin, HIGH);
  int distance = duration * 0.034 / 2; // Convert to cm

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Proximity alert within 15 cm
  if (distance > 0 && distance < 15) {
    digitalWrite(alertLed, HIGH);
  } else {
    digitalWrite(alertLed, LOW);
  }

  delay(100);
}