#include <Servo.h>

const int servoPin = 5;
const int interruptPin = 3;
Servo myservo;

volatile int servoCount = 0;
int delaytime = 10;
void setup() {
    Serial.begin(9600);
    myservo.attach(servoPin);
    pinMode(interruptPin, INPUT_PULLUP);
    myservo.write(0);
    attachInterrupt(digitalPinToInterrupt(interruptPin), servoISR, CHANGE);

}

void loop() {
    for (int i = 0; i <= 180; i++){
        myservo.write(i);
        delay(delaytime);
    }
    for (int i = 180; i >= 0; i--){
        myservo.write(i);
        delay(delaytime);
    }
    Serial.println(servoCount);
    servoCount=0;
}

void servoISR(){
    servoCount++;
}