/*
  Forum: https://forum.arduino.cc/t/vier-hc-sr-04-ultraschallsensoren-an-nur-5-pins-geht-das/1401048
  Wokwi: https://wokwi.com/projects/438987677757600769

  2025/08/11
  ec2021

*/

constexpr uint8_t trigPin {4};
constexpr uint8_t echoPin[] = {5, 14, 13, 12};
constexpr size_t numSensors = sizeof(echoPin) / sizeof(echoPin[0]);
constexpr int nameLen {4};
constexpr char Name[numSensors][nameLen] = {"VL", "VR", "HL", "HR"};

class usSensorClass {
  private:
    uint8_t echoPin;
    uint8_t triggerPin;
    float distance = 0;
    void trigger() {
      digitalWrite(triggerPin, HIGH);
      delayMicroseconds(10);
      digitalWrite(triggerPin, LOW);
    }
  public:
    void init(uint8_t ePin, uint8_t tPin) {
      echoPin = ePin;
      triggerPin = tPin;
      pinMode(echoPin, INPUT);
      pinMode(triggerPin, OUTPUT);
      digitalWrite(triggerPin, LOW);
    };
    float getDistance() {
      trigger();
      float duration = pulseIn(echoPin, HIGH);
      distance = (duration * .0343) / 2;
      return distance;
    };
};

usSensorClass usSensor[numSensors];

void setup() {
  Serial.begin(115200);
  for (int i = 0; i < numSensors; i++) {
    usSensor[i].init(echoPin[i], trigPin);
  }
}

void loop() {
  for (int i = 0; i < numSensors; i++) {
    Serial.print("Distance "); Serial.print(Name[i]); Serial.print(":\t");
    Serial.println(usSensor[i].getDistance());
    delay(25);
  }
  delay(150);
}