//WATER DISPENSER
#define trigger 5
#define echo 4
#define Relay 6

float time=0,distance=0;
int check = 0;
void setup()
{
Serial.begin(9600);

 pinMode(trigger,OUTPUT);
 pinMode(echo,INPUT);
 pinMode(Relay,OUTPUT);

 delay(2000);
}
 
void loop()
{
  Serial.println(distance);
  measure_distance();
 if(distance<5)
 {

  check = 1;
  digitalWrite(Relay,LOW);
 }
 else
 {
  check = 0;
  digitalWrite(Relay,HIGH);
   
 }

 if( check != 0){
  Serial.println("hand put");
  delay(3000);
 }else{
  Serial.println("no hand");
 }

 delay(500);
}

void measure_distance()
{
 digitalWrite(trigger,LOW);
 delayMicroseconds(2);
 digitalWrite(trigger,HIGH);
 delayMicroseconds(10);
 digitalWrite(trigger,LOW);
 delayMicroseconds(2);
 time=pulseIn(echo,HIGH);
 
 distance=time*200/20000;
 
 return 0;
}