const int sampleWindow = 100; // This might change in the near future
unsigned int sample;
 
#define SENSOR_PIN A0
const int red_ledBulb = 9;  // Analog connection of our LED
const int yellow_ledBulb = 10; // Analog connection of our LED
const int green_ledBulb = 11; // Analog connection of our LED
const int buzzer = 8;        // Analog connection of our buzzer
const int threshold = 75; //Variable (CAN BE CHANGED)

/* DOCUMENTATION

*Changes to source code 11/2/2023
- Red LED and Buzzer continuously ACTIVE
  (can be interrupted when NOISE LEVEL reached SAFE ZONE such as LESS THAN 60 to 70)
  (YELLOW - GREATER THAN 61 and LESS THAN 70 ONLY, GREEN - LESS THAN 60 ONLY)

- Added Serial Output for the peakToPeak Analog value var (Peak Analog)
- Added pinMode Functions:
  pinMode(red_ledBulb, OUTPUT);
  pinMode(yellow_ledBulb, OUTPUT);
  pinMode(green_ledBulb, OUTPUT);
  pinMode(buzzer, OUTPUT);
  (To add real world compatibility with LED and BUZZER)

- Added a DEBUF feature in Serial.print()
  (will now print a 4 digit and 1 digit decimal regardless of the value
  e.g (0342.0, 1023.0 etc))
  (Changed Serial.print() output to one line for proper comparison
  between Analog output and decibels.)
*/

void setup ()  
{   
  pinMode (SENSOR_PIN, INPUT); // Set the signal pin as input  
  
  Serial.begin(9600);

  pinMode(red_ledBulb, OUTPUT);
  pinMode(yellow_ledBulb, OUTPUT);
  pinMode(green_ledBulb, OUTPUT);
  pinMode(buzzer, OUTPUT);
}  
 
   
void loop ()  
{ 
  unsigned long startMillis= millis();                   // Start of sample window
  float peakToPeak = 0;                                  // peak-to-peak level

  unsigned int signalMax = 0;                            //minimum value
  unsigned int signalMin = 1024;                         //maximum value

                                                        // collect data for 100 mS (Changed based on earlier test and formula)
  while (millis() - startMillis < sampleWindow)
  {
    sample = analogRead(SENSOR_PIN);                    //get reading from microphone
    if (sample < 1024)                                  // toss out spurious readings
    {
        if (sample > signalMax)
        {
          signalMax = sample;                           // save just the max levels
        }
        else if (sample < signalMin)
        {
          signalMin = sample;                           // save just the min levels
        }
    }
  }
 
  peakToPeak = signalMax - signalMin;                    // max - min = peak-peak amplitude
  int decibels = map(peakToPeak,20,900,49.5,90);             //calibrate for deciBels

  int wholeNumber = int(peakToPeak);

  // Calculate the ones and tens place as integers
  int ones = wholeNumber % 1000;
  int tens = int((peakToPeak - wholeNumber) * 10);
  

  if (decibels <= 60) {
    digitalWrite(green_ledBulb, HIGH);
    digitalWrite(buzzer, LOW);
    digitalWrite(red_ledBulb, LOW);
    delay(100);
    digitalWrite(yellow_ledBulb, LOW);
    digitalWrite(red_ledBulb, LOW);
  } else if (decibels >= 61 && decibels <= 70) {
    digitalWrite(green_ledBulb, HIGH);
    digitalWrite(yellow_ledBulb, HIGH);
    digitalWrite(buzzer, LOW);
    digitalWrite(red_ledBulb, LOW);
    delay(100);
    digitalWrite(red_ledBulb, LOW);
  } else if (decibels >= threshold ) {
    digitalWrite(red_ledBulb, HIGH);
    digitalWrite(green_ledBulb, HIGH);
    digitalWrite(yellow_ledBulb, HIGH);
    digitalWrite(buzzer, HIGH);
    delay(100);
    digitalWrite(green_ledBulb, LOW);
    digitalWrite(yellow_ledBulb, LOW);
  }

  //FOR ACTUAL TESTING - remove "//" 
  Serial.print("Peak Analog: ");

  // Print leading zeros for the ones and tens place only if the whole number part is less than 1000
  if (wholeNumber < 1000) {
    if (ones < 100) {
      Serial.print("0");
    }
    if (ones < 10) {
      Serial.print("0");
    }
    if (tens < 10) {
    Serial.print("0");
  }
  }
  

  Serial.print(wholeNumber);
  Serial.print(".");
  Serial.print(tens);

  Serial.print(" || ");

  Serial.print("Loudness: ");
  Serial.print(decibels);
  Serial.println(" dB ");
} // LINEAR COMPUTATION