#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2); // Set the LCD address and dimensions

const int soundSensorPin = 0;        // KY-037 analog interface for input
const int dangerLevelThreshold = -42; // Microphone sensitivity threshold (-42 dB)
const int soundRecorderPin = 9;      // Digital pin connected to sound recorder module
const int greenLedPin = 6;
const int yellowLedPin = 7;
const int redLedPin = 5;

// Adjustable sensitivity parameters
float sensitivityFactor = 1.0;      // Sensitivity adjustment factor (0.1 to 1.0)
 
unsigned long previousMillis = 0;  // Variable to store the last time an action was performed
const long interval = 1000;        // Interval in milliseconds (0.1 second)

void setup() { 
Serial.begin(9600);

  pinMode(soundRecorderPin, INPUT);  // Set sound recorder pin as INPUT
  calibrateSoundSensor(); // Calibrate the sound sensor
  pinMode(greenLedPin, OUTPUT);
  pinMode(yellowLedPin, OUTPUT);
  pinMode(redLedPin, OUTPUT);

                 // Initialize serial communication at 9600 bits per second and for debugging
  lcd.init();                        // Initialize LCD
  lcd.backlight();                    // Turn on backlight 
}


void calibrateSoundSensor() {
  // Perform calibration by averaging readings over a short period
  int total = 0;
  for (int i = 0; i < 10; i++) { // Read 10 samples for calibration
    total += analogRead(soundSensorPin);
    delay(50); // Adjust delay as needed
  }
  int baseThreshold = total / 10; // Set baseThreshold to the average value
}

void updateSoundGraph(int decibels) {
  // Calculate the number of bars based on the decibel range
  int numBars = map(decibels, 0, 100, 0, 16); // Map decibels to LCD width (16 columns)

  lcd.setCursor(0, 1);
  for (int i = 0; i < numBars; i++) {
    lcd.write(255); // Display a filled bar (custom character or ASCII value)
  }
  for (int i = numBars; i < 16; i++) {
    lcd.print(" "); // Clear remaining space
  }
}


void loop() {
  unsigned long currentMillis = millis(); // Get the current time in milliseconds

  if (currentMillis - previousMillis >= interval) { // Check if the interval has elapsed
    previousMillis = currentMillis; // Update the previous time to the current time

    int soundLevel = analogRead(soundSensorPin); // Read sound level from sensor
    int decibels = map(soundLevel, 0, 1023, 0, 115); // Map analog value to decibels 

    // Adjust threshold based on microphone sensitivity
    int threshold = dangerLevelThreshold + (int)(sensitivityFactor * decibels);

    // Debugging output
    Serial.print("Raw Analog Reading: ");
    Serial.print(soundLevel);
    Serial.print(" Mapped Decibels: ");
    Serial.println(decibels);
    delay(1000); // Delay for 1 second

    lcd.setCursor(0, 0);
    lcd.print("Decibels: ");
    lcd.print(decibels);

    // Update sound graph on LCD
    updateSoundGraph(decibels);

    // Display sound level status on LCD
    if (decibels >= 0 && decibels <= 50){
      lcd.setCursor(0, 1);
      lcd.print("Ordinary Classroom   ");
    } if (decibels > 51 && decibels <= 65){
      lcd.setCursor(0, 1);
      lcd.print("Unruly Classroom    ");
    } if (decibels > 66 && decibels <= 100){
      lcd.setCursor(0, 1);
      lcd.print("Unacceptable Classroom Noise    ");
      // Trigger sound alert when every danger level is reached
      triggerSoundAlert();
    }

    // Control LED lights based on sound levels...
    if (decibels >= 0 && decibels <= 50){
      digitalWrite(greenLedPin, HIGH);  // Turn on the green LED
      digitalWrite(yellowLedPin, LOW);  // Turn off the yellow LED
      digitalWrite(redLedPin, LOW);     // Turn off the red LED
    } if (decibels > 51 && decibels <= 65){
      digitalWrite(greenLedPin, LOW);   // Turn off the green LED
      digitalWrite(yellowLedPin, HIGH); // Turn on the yellow LED
      digitalWrite(redLedPin, LOW);     // Turn off the red LED
    } if(decibels > 66){
      digitalWrite(greenLedPin, LOW);   // Turn off the green LED
      digitalWrite(yellowLedPin, LOW);   // Turn off the yellow LED
      digitalWrite(redLedPin, HIGH);    // Turn on the red LED
    }
  }
}




void triggerSoundAlert() {
  tone(soundRecorderPin, 20000, 20000); // Example tone (20000 Hz for 6 seconds)
  delay(1000); // Wait for the tone to finish
  noTone(soundRecorderPin); // Stop the tone
}