#define trigPin 12
#define echoPin 11
const int segmentPins[] = {8, 9, 4, 5, 6, 2, 3}; // Pins for segments of 7-segment display
//const int commonCathodePin1 = 10; // Pin 10 of 7-segment display connected to GND through 220 ohm resistor
//const int commonCathodePin2 = 7;  // Pin 7 of 7-segment display connected to GND through 220 ohm resistor

int buzzerPin = 10;

char segments[10] = { // Lookup table for displaying digits on 7-segment display
  0b0111111, // 0
  0b0000110, // 1
  0b1011011, // 2
  0b1001111, // 3
  0b1100110, // 4
  0b1101101, // 5
  0b1111101, // 6
  0b0000111, // 7
  0b1111111, // 8
  0b1101111  // 9
};

long duration; // variable to store the pulse duration
int distanceCm; // variable to store the distance in centimeters

void setup() {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT); // Set trig pin as output
  pinMode(echoPin, INPUT); // Set echo pin as input

  pinMode(buzzerPin, OUTPUT);

  for (int pin : segmentPins) {
    pinMode(pin, OUTPUT);
  }
  //pinMode(commonCathodePin1, OUTPUT);
  //pinMode(commonCathodePin2, OUTPUT);
  //digitalWrite(commonCathodePin1, LOW); // Turn off display (common cathode)
  //digitalWrite(commonCathodePin2, LOW); // Turn off display (common cathode)
}

void loop() {
  // Trigger the HC-SR04 sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echo pulse duration
  duration = pulseIn(echoPin, HIGH);

  // Calculate distance in centimeters
  distanceCm = duration * 0.034 / 2;

  // Invert the logic for water level display (higher distance = lower water level)
  int waterLevel = map(distanceCm, 50, 170, 9, 0); // Adjust max distance based on your setup
  //map(value, lower bound(HC-SR04 range), upper bound(HC-SR04 range), lowerbound(output digit), upper bound((output digit)) )
  
  char dist_str[8];
  dtostrf(waterLevel, 6, 2, dist_str); // int to string convertion
  //Serial.println(dist_str);
  
  // Print the water level and distance for debugging purposes
  //Serial.print("Water Level (Inverted): ");
  //Serial.print(waterLevel);
  //Serial.print(", Distance (cm): ");
  //Serial.println(distanceCm);
  displayDigit(waterLevel);
  //soundAlarm(waterLevel);
  
}

void displayDigit(int number) {
  if (number < 0 || number > 9) {
    // Handle invalid digit (e.g., turn off/turn on all segments)
    for (int pin : segmentPins) {
      digitalWrite(pin, HIGH); // Assuming common cathode, turn on all segments here HIGH = OFF
      
    }
    return;
  }
  //digitalWrite(commonCathodePin1, HIGH); // Turn on display
  //digitalWrite(commonCathodePin2, HIGH); // Turn on display
  for (int i = 0; i < 7; i++) {
    digitalWrite(segmentPins[i], !(segments[number] & (1 << i)));
  }
  //digitalWrite(commonCathodePin1, LOW); // Turn off display briefly
  //digitalWrite(commonCathodePin2, LOW); // Turn off display briefly
}

void soundAlarm(int number) {
  if (number >= 6) {
    // Police siren effect
    for (int i = 0; i < 3; i++) {
      tone(buzzerPin, 660, 250); // E5
      delay(250);
      tone(buzzerPin, 440, 250); // A4
      delay(250);
    }
  } else if (number >= 4) {
    // General siren effect
    for (int i = 440; i <= 880; i += 10) {
      tone(buzzerPin, i, 30);
      delay(30);
    }
    for (int i = 880; i >= 440; i -= 10) {
      tone(buzzerPin, i, 30);
      delay(30);
    }
  }
}