#include <Servo.h>

const int LED = 13;  // Define LED (pin 13 is on-board led.) 
bool LEDstate = LOW;
Servo servoA;  // create servo objects to control 
Servo servoB;
int posA = 0;    // variables to store the servo positions
int incA = 1;
int delayA = 15;
int TimeA, prevTimeA;
//----------------------
int posB = 30;
int incB = 1;
int delayB = 2;
int TimeB, prevTimeB;
long counter = 0;


void setup() {
  pinMode(LED, OUTPUT); // Defining LED pin as OUTPUT Pin
  servoA.attach(3);  // attaches the servoA on pin 3 to the servo object
  prevTimeA = millis();
  servoB.attach(6);  // attaches the servoB on pin 6 to the servo object
  prevTimeB = millis();  
}  

void loop() {
  // This coded blinks on-board led to get some estimate of simulation speed.
  // 1 million loops takes about 6 seconds.  Real Arduino?
  counter = counter + 1;
  if (counter == 100000) {
    LEDstate = not LEDstate;
    counter = 0;
    digitalWrite(LED, LEDstate);
  }
  // This block controls servoA
  TimeA = millis();
  if ((TimeA - prevTimeA) >= delayA)  {
     if (posA > 179) {
       incA = -1;
       delayA = 3;
       }
     if (posA < 1) {
       incA = 1;
       delayA = 15;
       }
     posA = posA + incA;
     servoA.write(posA);
     prevTimeA = millis();
  }   


// This block controls servoB
  TimeB = millis();
  if ((TimeB - prevTimeB) >= delayB)  {
     if (posB > 120) {
       incB = -1;
       delayB = 8;
       }
     if (posB < 30) {
       incB = 1;
       delayB = 2;
       }
     posB = posB + incB;
     servoB.write(posB);
     prevTimeB = millis();
  }   

/* //This is typical loop control of a servo.  Blocking code isn't good.
  for (posA = 180; posA >= 0; posA -= 1) { // goes from 180 degrees to 0 degrees
    servoA.write(posA);              // tell servo to go to position in variable 'pos'
    delay(3);                       // waits 15ms for the servo to reach the position
  }
 */ 
}