//source http://madrid.verkstad.cc/en/course-literature/continuous-rotation-servo/
#include <Servo.h>
Servo myservo;
void setup() {
myservo.attach(9);
pinMode(2, INPUT);
}
void loop() {
if(digitalRead(2) == HIGH){
myservo.write(45); //you must find the absolute # that stops the servo motion
delay(1000);
myservo.write(100);
delay(1000);
}
else{
digitalWrite(9, LOW);
}
}