/*
  My first Arduino program/ This controls two servos by using a pot. 
  An LED lights when the pot's value changes, and each servo rotates 
  in opposite directions.
*/
#include <Servo.h>

Servo myservo; 
Servo myservo2; 

int potpin = 7; // pin # (analog) that potentiometer is on
int s1pin  = 2; // pin # (pwm) that servo 1 is on
int s2pin  = 3; // pin # (pwm) that servo 2 is on
int val    = 0; // variable to store last value from potentiometer
int pval   = 0;

void setup() {
  myservo.attach(s1pin);  // wake up servo 1
  myservo2.attach(s2pin); // wake up servo 2
}

void loop() {
  /*Read pot value, scale to range 0-180.*/
  val = map(analogRead(potpin),0,1023,0,180);
  myservo.write(val);
  myservo2.write(180-val);
  /*Light up LED if pot value is new.*/
  if (val != pval) {
    digitalWrite(7,HIGH);
    delay(5);
    digitalWrite(7,LOW);
    pval = val;
  }
  /*A final pause.*/
  delay(15);
}