Engine.pde

void DoEngine() {
  switch (engine_state) {
    case ENGINE_OFF:
      if (control_state == CONTROL_START) {
        TransitionEngine(ENGINE_STARTING);
      }
      SetThrottleAngle(0);
      break;
    case ENGINE_ON:
      if (control_state == CONTROL_OFF & millis()-control_state_entered > 100) {
        TransitionEngine(ENGINE_OFF);
      }
      if (control_state == CONTROL_START) {
        TransitionEngine(ENGINE_STARTING);
      }
      if (P_reactorLevel == OFF & millis()-engine_state_entered > 10000) { //if reactor is at low vacuum after ten seconds, engine did not catch, so turn off
        TransitionEngine(ENGINE_OFF);
      }
      break;
    case ENGINE_STARTING:
      if (control_state == CONTROL_OFF & millis()-control_state_entered > 100) {
        TransitionEngine(ENGINE_OFF);
      }
      SetThrottleAngle(100); // % open
//      #ifdef INT_HERTZ
//        // Use RPM detection to stop cranking automatically
//        if (CalculatePeriodHertz() > 40) { //if engine is caught, stop cranking
//          TransitionEngine(ENGINE_ON);
//        }
//        if (engine_end_cranking < millis()) { //if engine still has not caught, stop cranking
//          TransitionEngine(ENGINE_OFF);
//        }
//      #else
        // Use starter button in the standard manual control configuration (push button to start, release to stop cranking)
        if (control_state == CONTROL_ON) {
          TransitionEngine(ENGINE_ON);
        }
//      #endif
      break;
     case ENGINE_GOV_TUNING:
      if (control_state == CONTROL_OFF) {
        TransitionEngine(ENGINE_OFF);
      }
      break;
  }
}

void TransitionEngine(int new_state) {
  //can look at engine_state for "old" state before transitioning at the end of this method
  engine_state_entered = millis();
  switch (new_state) {
    case ENGINE_OFF:
      //analogWrite(FET_IGNITION,0);
      analogWrite(FET_STARTER,0);
      Serial.println("# New Engine State: Off");
      TransitionMessage("Engine: Off         ");
      break;
    case ENGINE_ON:
      //analogWrite(FET_IGNITION,255);
      analogWrite(FET_STARTER,0);
      Serial.println("# New Engine State: On");
      TransitionMessage("Engine: Running    ");
      break;
    case ENGINE_STARTING:
      //analogWrite(FET_IGNITION,255);
      analogWrite(FET_STARTER,255);
      engine_end_cranking = millis() + engine_crank_period;
      Serial.println("# New Engine State: Starting");
      TransitionMessage("Engine: Starting    ");
      break;
    case ENGINE_GOV_TUNING:
      //analogWrite(FET_IGNITION,255);
      analogWrite(FET_STARTER,0);
      Serial.println("# New Engine State: Governor Tuning");
      TransitionMessage("Engine: Gov Tuning  ");
      break;
  }
  engine_state=new_state;
}

void SetThrottleAngle(double percent) {
 Servo_Throttle.write(throttle_valve_closed + percent*(throttle_valve_open-throttle_valve_closed));
 //servo2_pos = percent;
}