/*
  

*/

constexpr uint8_t trigPin {3};
constexpr uint8_t echoPin {2};
constexpr uint8_t outPin  {4};

unsigned long lastTime = 0;
unsigned long duration = 0;


void trigger(){
  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(10);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
}

void getPulse(){
  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin,HIGH);
  if (duration > 0){
    Serial.println(duration/58);
  } else {
    Serial.println("Timeout");
  }
}

void sendPulse(){
  if (duration > 0){
    digitalWrite(outPin,HIGH);
    delay(duration/100);
    digitalWrite(outPin,LOW);
    duration = 0;
  }
}


void setup() {
  Serial.begin(115200);
  pinMode(outPin, OUTPUT);
  digitalWrite(outPin,LOW);
  
}

void loop() {
  if (millis()-lastTime > 2000){
    lastTime = millis();
    trigger();
    getPulse();
  }
    sendPulse();
}