void setup() {
  Serial.begin(115200);
  Serial.println("Hello World!");

  pinMode(3, INPUT_PULLUP);

  turnMachineStep(2);   // leave it as if it had run once? I give up
}

void loop() {
  if (!turnMachineStep(1) and !digitalRead(3)) {
  	turnMachineStep(0);
  }
}

// command 0 - reset this machine.
// command 1 - normal step this machine, return 0 when done/no longer busy
// command 2 - initialise this machine - mystery? kludged here

unsigned char turnMachineStep(unsigned char command)
{
  static byte frame = 0;
  static unsigned long lastTime = 0;
  static unsigned long tween = 1;

  static unsigned char busy = 0;        // not busy!
  static unsigned char returnValue = 0; // not done - will change if not

// kludge ahead. I give up, pound a nail in it.

  if (command == 2) {
      tween = 1;
      frame = 0;

      returnValue = 1;	// we done
      busy = 0;				// we not
 //     initialised = true;
      return returnValue;
  }

 if (command == 0) {
    frame = 0;
    lastTime = millis();
    tween = 200;		// next call gets immediate enough attention.
    busy = 1;

    return (1);
  }

  if (!busy) 
    return (0);

  if (millis() - lastTime < tween)
    return (1);

  lastTime = millis();

  switch (frame) {
    case 0 :
      Serial.println("               render frame 0");
      tween = 200;
      frame++;
      break;

    case 1 ... 8 : /* case 1 - 21 elided here */
      Serial.print("               render frame ");
      Serial.println(frame);
      tween = 200;
      frame++;
      break;


    case 9 :
      Serial.println("               render frame 9. Done?");
      tween = 15;
      frame = 0;

      returnValue = 1;		// we done
      busy = 0;				// we not
      break;
  }

  return returnValue;
}