int timer = 200;           // The higher the number, the slower the timing.
int ledPins[] = {  2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};       // an array of pin numbers to which LEDs are attached
int pinCount = 11;           // the number of pins (i.e. the length of the array)

int LedPin[] = { 17, 14, 15, 16 };     // an array of pin numbers to which LEDs are attached


void setup()
{
  // use a for loop to initialize each pin as an output:
  for (int digitalpin = 2; digitalpin < 13; digitalpin++)
  {
    pinMode(digitalpin, OUTPUT);
  }
  // the array elements are numbered from 0 to (pinCount - 1).

  for (int analogpins = 0; analogpins < 4; analogpins++)
  {
    pinMode(LedPin[analogpins], OUTPUT);
  }


}

void loop()
{

 for (int analogpins = 0; analogpins < 4; analogpins++)
  {
    // turn the pin on:
    digitalWrite(LedPin[analogpins], HIGH);
    delay(timer);
    // turn the pin off:
    digitalWrite(LedPin[analogpins], LOW);
  }
  
  // Speed up over 25 cycles, delays of 100 to 50
  for (int timer = 100; timer > 10; timer -= 2)
  {
    Cycle(timer);
  }
  // Slow down over 25 cycles, delays of 50 to 100
  for (int timer = 10; timer < 100; timer += 2)
  {
    Cycle(timer);
  }
}






void Cycle(int delayTime)
{
  // loop from the lowest pin to the highest:
  for (int digitalpin = 2; digitalpin < 13; digitalpin++)
  {
    // turn the pin on:
    digitalWrite(digitalpin, HIGH);
    delay(delayTime);
    // turn the pin off:
   // digitalWrite(thisPin, LOW);
  }

    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
    digitalWrite(9, LOW);
    digitalWrite(10, LOW);
    digitalWrite(11, LOW);
    digitalWrite(12, LOW);
    

  for (int analogpins = 0; analogpins < 4; analogpins++)
  {
    // turn the pin on:
    digitalWrite(LedPin[analogpins], HIGH);
    delay(timer);
    // turn the pin off:
    digitalWrite(LedPin[analogpins], LOW);
  }
}