// https://www.youtube.com/watch?v=M-UKXCUI0rE&list=PLGs0VKk2DiYw-L-RibttcvK-WBZm8WLEP&index=53
// https://www.youtube.com/watch?v=BTMMNsL0_b0&list=PLGs0VKk2DiYw-L-RibttcvK-WBZm8WLEP&index=54
// https://www.youtube.com/watch?v=2hwrDSVHQ-E&list=PLGs0VKk2DiYw-L-RibttcvK-WBZm8WLEP&index=55


#include <Arduino.h>

int trigPin = 12;
int echoPin = 11;
int pingTravleTime;
float distance;
const int pulsTime = 40; // uS
const float pingTimeToDistance = 0.017; // uS to cm, travletime[s] * 340 m/s / 2

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(pulsTime);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(pulsTime);
  digitalWrite(trigPin, LOW);
  pingTravleTime = pulseIn(echoPin, HIGH);
  delay(25);
  Serial.print("Ping Time: ");
  Serial.print(pingTravleTime);

  distance = pingTravleTime * pingTimeToDistance;
  Serial.print(" Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

}