#define TRIGGER_PIN 9  // Pino Trigger do HC-SR04
#define ECHO_PIN 8    // Pino Echo do HC-SR04
#define SAMPLE_SIZE 5 // Tamanho do buffer de amostras para cálculos

float samples[SAMPLE_SIZE];
int sampleIndex = 0;
float movingAverage = 0;

void setup() {
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(9600);
}

void loop() {
  float distance = measureDistance();

  if (distance > 0) {
    samples[sampleIndex] = distance;
    sampleIndex = (sampleIndex + 1) % SAMPLE_SIZE;

    // Cálculos estatísticos
    float mean = calculateMean(samples, SAMPLE_SIZE);
    float median = calculateMedian(samples, SAMPLE_SIZE);
    float mode = calculateMode(samples, SAMPLE_SIZE);
    float stddev = calculateStdDev(samples, SAMPLE_SIZE, mean);
    movingAverage = calculateMovingAverage(samples, SAMPLE_SIZE);

    // Exibir resultados
    Serial.print("Distância: ");
    Serial.print(distance);
    Serial.print(" cm | Média: ");
    Serial.print(mean);
    Serial.print(" | Mediana: ");
    Serial.print(median);
    Serial.print(" | Moda: ");
    Serial.print(mode);
    Serial.print(" | Desvio Padrão: ");
    Serial.print(stddev);*/
    Serial.print(" | Média Móvel: ");
    Serial.println(movingAverage);

    delay(100); // Ajuste o intervalo conforme necessário
  }
}

float measureDistance() {
  // Enviar pulso de trigger
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);

  // Medir o tempo do pulso no pino ECHO
  long duration = pulseIn(ECHO_PIN, HIGH);

  // Calcular a distância em cm (velocidade do som no ar é ~343 m/s)
  float distance = duration * 0.034 / 2;

  return distance;
}

float calculateMean(float data[], int size) {
  float sum = 0;
  for (int i = 0; i < size; i++) {
    sum += data[i];
  }
  return sum / size;
}

float calculateMedian(float data[], int size) {
  float sorted[size];
  memcpy(sorted, data, size * sizeof(float));
  for (int i = 0; i < size - 1; i++) {
    for (int j = i + 1; j < size; j++) {
      if (sorted[i] > sorted[j]) {
        float temp = sorted[i];
        sorted[i] = sorted[j];
        sorted[j] = temp;
      }
    }
  }
  if (size % 2 == 0) {
    return (sorted[size / 2 - 1] + sorted[size / 2]) / 2;
  } else {
    return sorted[size / 2];
  }
}

float calculateMode(float data[], int size) {
  float mode = data[0];
  int maxCount = 0;
  for (int i = 0; i < size; i++) {
    int count = 1;
    for (int j = i + 1; j < size; j++) {
      if (data[j] == data[i]) count++;
    }
    if (count > maxCount) {
      maxCount = count;
      mode = data[i];
    }
  }
  return maxCount > 1 ? mode : NAN;
}

float calculateStdDev(float data[], int size, float mean) {
  float sumSq = 0;
  for (int i = 0; i < size; i++) {
    sumSq += pow(data[i] - mean, 2);
  }
  return sqrt(sumSq / size);
}

float calculateMovingAverage(float data[], int size) {
  float sum = 0;
  for (int i = 0; i < size; i++) {
    sum += data[i];
  }
  return sum / size;
}