const int trigPin = 5;
const int echoPin = 18;
#define LED1 23
#define LED2  22
//define sound speed in cm/uS
#define SOUND_SPEED 0.034
#define CM_TO_INCH 0.393701

long duration;
float distanceCm;
float distanceInch;

int i = 0;

void setup() {
  Serial.begin(115200); // Starts the serial communication
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); 
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
}

void loop() {
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
    duration = pulseIn(echoPin, HIGH);
    distanceCm = duration * SOUND_SPEED/2;
    
  if (distanceCm  >= 50)
  {
    i = 1;
  }
  
  if(distanceCm  <= 30 )
  {
    i = 2;
  }
  
  if(i == 2)
  {
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
  }
  if(i == 1)
  {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);//ปั๊มน้ำ2
  }
   else 
  {
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
  }
  Serial.print("Distance (cm): ");
  Serial.println(distanceCm);
  delay(100);
}