int servo1 = 11, servo2 = 10;
int step = 5, dir = 6;

#include <Servo.h>
Servo s1, s2;
int pos1, pos2;

void setup() {
  // put your setup code here, to run once:
  s1.attach(servo1);
  s2.attach(servo2);

  pinMode(step, OUTPUT);
  pinMode(dir, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(dir,LOW);
  digitalWrite(step,HIGH);
  for(pos1=0; pos1<=180; pos1++) {
    s1.write(pos1);
    s2.write(180-pos1);   
    delay(10);
  }
  digitalWrite(step,LOW);
  for(pos1=180; pos1>=0; pos1--) {
    s1.write(pos1);
    s2.write(180-pos1);
    delay(10);
  }
}