#include <Servo.h>
#include <stdio.h>

#define TRIG_PIN 3
#define ECHO_PIN 26
#define SERVO_PIN 17
Servo servo;
void setup()
{
   servo.attach(SERVO_PIN);
    // Ultrasonic sensor pins
    pinMode(TRIG_PIN, OUTPUT);
    pinMode(ECHO_PIN, INPUT);
      Serial.begin(9600);

}

int calcDistance()
{
    // Trigger ultrasonic sensor
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);
    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);
    digitalWrite(TRIG_PIN, LOW);

    // Measure the pulse duration on ECHO pin
    long duration = pulseIn(ECHO_PIN, HIGH);
    int distance = duration * 0.034 / 2;
    return distance;
}

void loop()
{
    int dis = calcDistance();
    if (dis <= 200)
    {
        servo.write(45);
    }
    else
    {
         servo.write(180);
    }

    delay(500);
}