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How to Turn on Lights Documentation

This project implements an interactive lighting system that simulates the experience of lighting a lantern using breath. The user must hold a pressure-sensitive FSR sensor and then blow into a microphone (MAX4466) to activate RGB LED groups.

• The LEDs gradually fade in instead of lighting up instantly, creating a smooth and immersive lighting experience.
• Each blow activates the next group of LEDs, and a minimum time gap is enforced between consecutive blows to ensure a natural interaction.
• Once all LED groups are lit, they stay on for 30 seconds before resetting.
• If the user releases the lantern (FSR < threshold) before all LEDs are lit, the system resets to its initial state.

How the System Works

1. Idle State:
   • The system waits for the FSR to be pressed (FSR > 800) before accepting microphone input.
   • If the user releases the FSR before lighting all groups, the system resets.
2. Blowing Detection:
   • When the microphone detects a reading of 1023, it registers a valid blow event.
   • A 3-second gap is enforced before allowing another blow.
3. LED Activation:
   • Each valid blow activates the next LED group, with a smooth fade-in over 5 seconds.
   • The sequence is:
     1. Blow 1: Group 1 (3 LEDs) fades in.
     2. Blow 2: Group 2 (2 LEDs) fades in.
     3. Blow 3: Group 3 (1 LED) fades in.
   • After all three groups are lit, the LEDs stay on for 30 seconds.
4. Auto-Reset:
   • After 30 seconds, the system automatically resets, turning off all LEDs.

LED Fade-In Function

void fadeInLED(int pin) {
  int steps = 255;  
  int delayTime = 5000 / steps; // Fade in over 5 sec
  for (int i = 0; i <= 255; i++) {
    analogWrite(pin, i);
    delay(delayTime);
  }
}

Main Loop: Sensor Processing

void loop() {
  unsigned long now = millis();
  int fsrValue = analogRead(fsrPin);
  int micValue = analogRead(micPin);

  Serial.print("Mic: ");
  Serial.print(micValue);
  Serial.print(" | FSR: ");
  Serial.println(fsrValue);

  // If level 3 is reached, ignore FSR and keep LEDs on for fullLitDuration
  if (currentLevel == 3) {
    if (now - fullLitStart >= fullLitDuration) {
      Serial.println("Full-lit duration reached. Resetting system.");
      resetSystem();
    }
    delay(50);
    return;
  }

  // For levels below 3, process mic only when lantern is held
  if (fsrValue > fsrThreshold) {
    if (now - lastBlowTime >= blowGap) {  // Enforce 3 sec gap
      if (micValue >= micBlowThreshold) {
        if (!blowActive) { // Rising-edge detection
          if (currentLevel < 3) {
            currentLevel++;
            Serial.print("Blow detected. Increasing level to ");
            Serial.println(currentLevel);
            if (currentLevel == 1) {
              fadeInGroup1();
            } else if (currentLevel == 2) {
              fadeInGroup2();
            } else if (currentLevel == 3) {
              fadeInGroup3();
              fullLitStart = now; // Start 30-sec timer
            }
            lastBlowTime = now;
          }
          blowActive = true;
        }
      } else {
        blowActive = false; // Reset flag when mic reading falls below threshold
      }
    }
  } else {
    resetSystem();  // If not held, reset system
  }

  delay(50);
}