const int trigPin = 5;
const int echoPin = 18;

#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceCm;
float distanceInch;

void setup() {
  Serial.begin(9800); 
  pinMode(trigPin, OUTPUT); 
  pinMode(echoPin, INPUT); 
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
 
  duration = pulseIn(echoPin, HIGH);
  
  distanceCm = duration * SOUND_SPEED/2;
  

  distanceInch = distanceCm * CM_TO_INCH;
  
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);
  Serial.print("Distance (inch): ");
  Serial.println(distanceInch);
  
  delay(1000);
}

//+ralay
const int trigPin = 5;
const int echoPin = 18;
int relay = 15;
#define SOUND_SPEED 0.034
#define CM  1

long duration;
float distanceCm;

void setup() {
  Serial.begin(9800); 
  pinMode(relay, OUTPUT);
  pinMode(trigPin, OUTPUT); 
  pinMode(echoPin, INPUT); 
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  if ( distanceCm >= 15) {
  digitalWrite(relay, 0);
  }
  if ( distanceCm <= 10) {
  digitalWrite(relay, 1);
  }
  duration = pulseIn(echoPin, HIGH);
  distanceCm = duration * SOUND_SPEED/2;
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm); 
  delay(500);
}
// เสียง
const int trigPin = 5;
const int echoPin = 18;
int relay = 15;
int buzzerpin = 16 ;
#define SOUND_SPEED 0.034
#define CM  1

long duration;
float distanceCm;

void setup() {
  Serial.begin(9800); 
  pinMode(relay, OUTPUT);
  pinMode(trigPin, OUTPUT); 
  pinMode(echoPin, INPUT); 
  pinMode(buzzerpin,OUTPUT);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  if ( distanceCm >= 15) {
  digitalWrite(relay, 0);
  digitalWrite(buzzerpin,HIGH);
  }
  if ( distanceCm <= 10) {
  digitalWrite(relay, 1);
  digitalWrite(buzzerpin,LOW);
  }
  duration = pulseIn(echoPin, HIGH);
  distanceCm = duration * SOUND_SPEED/2;
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm); 
  delay(500);
}