const int rolepin = 23;
#define TRIG_PIN 5
#define ECHO_PIN 18
const int DISTANCE_THRESHOLD = 50; 
float duration_us, distance_cm;
void setup() {
  pinMode(rolepin, OUTPUT);
 digitalWrite(rolepin, HIGH);
 pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  Serial.begin(115200);
}
void loop() {
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration_us = pulseIn(ECHO_PIN, HIGH);
  distance_cm = 0.017 * duration_us;  
 if(distance_cm < 10)
{         
      digitalWrite(rolepin, LOW);
      delay(2000);
     digitalWrite(rolepin, HIGH);
     delay(2000);
}
else{
      digitalWrite(rolepin, HIGH);
}
 Serial.print("distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(500);
}