function 4

int filamentTimeout(){

  // if the filament has not moved in five minutes (300k ms) the filament must be stalled or jammed
  // sound the blinking alarm

  static unsigned long previousMillis = 0;        // store for next time function is called
         unsigned long currentMillis = millis();  // get current time elapsed
  const  unsigned long timeoutInterval = 300000;  // can be changed to make this function more or less 'sensitive'

         double  currentFilament = 0;              // current amount of filament used
  static double previousFilament = 0;              // check currentFilament against this to see if it's moving or not

  currentFilament = filamentUsed(500);            // call this function in order to see how much filament has been used

  if(currentFilament > previousFilament){         // we can safely assume that the filament IS indeed moving
    previousFilament = currentFilament;           // update to check against this value next time function is called
    return 0;                                     // don't sound alarm
    }
  else{                                           // otherwise, filament might be jammed
    if(currentMillis - previousMillis >= timeoutInterval){ // has the timeout interval passed?
      return 1;                                            // sound alarm - filament is not moving and timeout passed
    }
    else{
      previousMillis = currentMillis;                     // reset timeout if it hasn't passed
      return 0;                                           // don't sound alarm
      }
    }

  }