[NEW] Standby Handler

[AlexanderTonn]

 :rocket: Please describe your feature request

• turn of background light of ILI9341 for increasing lifetime and saving energy

•  :pencil2: Describe the solution you'd like

• turn off display after x-seconds
• turn it on if touch input was detected

auto StandbyHandler(uint32_t &uiElapsed, uint32_t uiTarget, bool xTouched) -> void
{
  static bool xStandby = false;

  if (!xTouched 
      && millis() - uiElapsed >= uiTarget * 1000 
      && !xStandby)
  {
    // fade out HMI if no touch input

      xStandby = true;
      for (auto i = uiTftBrightness; i > 0; i--)
      {
        analogWrite(TFT_LED, i);
        delay(10);
      }
  }
  // Turn on, if touch was pressed
  else if (xTouched && xStandby)
  {
    xStandby = false;
    for (auto i = 0; i < uiTftBrightness; i++)
    {
      analogWrite(TFT_LED, i);
      delay(10);
    }
  }

  if(xTouched)
    uiElapsed = millis(); // reset timer

}

I call the function in my hmi touch Loop. One time before touch was detected and one time after touch was detected. With this two calls i know with the passing of trueor falsewhether touch was detected and i can start timers for turning off the background light.

auto hmiTouch() -> void
{
  StandbyHandler(uiTimeWithNoTouch, uiStandbyTargetTime, false);

  if (touch.touched())
  {
    StandbyHandler(uiTimeWithNoTouch, uiStandbyTargetTime, true);
    TS_Point touchPoint = touch.getPoint();
    touchPoint.x = map(touchPoint.x, TOUCH_X_MIN, TOUCH_X_MAX, tft.width(), 0);
    touchPoint.y = map(touchPoint.y, TOUCH_Y_MIN, TOUCH_Y_MAX, 0, tft.height());

// ...

 :pushpin: Describe alternatives you've considered

Additional context

:white_check_mark: Tasks