//PendTech
//automatic railway gate
#include <Servo.h>
Servo servoMain;//Define our servo
 int trigpin = 10; 
 int echopin = 11;
 int distance; 
 float duration;
 float cm;

 void setup()
{
servoMain.attach(9); // servo on digital pin 10

pinMode(trigpin, OUTPUT);

pinMode(echopin, INPUT);
}

void loop()
{

digitalWrite(trigpin, LOW);
delay(1);

digitalWrite(trigpin, HIGH);

delayMicroseconds(50);

digitalWrite(trigpin, LOW);

duration= pulseIn(echopin, HIGH);

cm=(duration/68.82);
distance=cm;

if (distance<10)
{

servoMain.write(90); // Turn Servo back to center position (90 degrees)
delay(4000);
}
else
{

servoMain.write(0);
delay(20);
}
}