const byte trigPin = 13;
const byte echoPin = 12;
const byte buzzerPin = 27;
byte ledPins[] = { 15, 2, 4, 5, 18, 19, 21, 22, 23, 14 };

void setup() {
  Serial.begin(115200);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  for (int i = 0; i < sizeof(ledPins); i++) {
    pinMode(ledPins[i], OUTPUT);
  }

  indicatorTest();
}

void loop() {
  int dist = getDist();
  indicator(dist);

  delay(100);
}

void indicatorTest() {
  for (int i = 0; i < sizeof(ledPins); i++) {
    digitalWrite(ledPins[i], HIGH);
    delay(100);
  }
  for (int i = sizeof(ledPins)-1; i >= 0; i--) {
    digitalWrite(ledPins[i], LOW);
    delay(100);
  }
}

void ledHigh(byte ledCount) {
  for (int i = 0; i < ledCount; i++) {
    digitalWrite(ledPins[i], HIGH);
    delay(10);
  }
  for (int i = ledCount-1; i >= 0; i--) {
    digitalWrite(ledPins[i], LOW);
    delay(10);
  }
}

void buzzer() {
  for (int i = 0; i < 2; i++) {
    digitalWrite(buzzerPin, HIGH);
    delay(2);
    digitalWrite(buzzerPin, LOW);
    delay(2);
  }
}

void indicator(int dist) {
  if (dist <= 150 && dist > 135) {
    ledHigh(1);
  } else if (dist <= 135 && dist > 120) {
    ledHigh(2);
  } else if (dist <= 120 && dist > 105) {
    ledHigh(3);
  } else if (dist <= 105 && dist > 90) {
    ledHigh(4);
  } else if (dist <= 90 && dist > 75) {
    ledHigh(5);
  } else if (dist <= 75 && dist > 60) {
    ledHigh(6);
  } else if (dist <= 60 && dist > 45) {
    ledHigh(7);
  } else if (dist <= 45 && dist > 30) {
    ledHigh(8);
  } else if (dist <= 30 && dist > 15) {
    ledHigh(9);
  } else if (dist <= 15 && dist > 0) {
    ledHigh(10);
  } else {
    ledHigh(0);
  }
  if (dist < 150) {
    int buzzerInterval = map(dist, 0, 149, 0, 1000);
    buzzer();
    delay(buzzerInterval);
  }
}

int getDist() {
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  long int t = pulseIn(echoPin, HIGH);
  float v = 0.034;
  long int d = (v*t)/2;

  return d;
}