 
 static inline __attribute__((always_inline)) void drawBacklightSlider()
 {
-  //TODO: only erase the button, not the slider
-  button_t sliderButton;
+  static button_t sliderButton;
 
   tft.startWrite();
-  tft.writeFillRect( sliderArea.x, sliderArea.y, sliderArea.w, sliderArea.h, ILI9341_BLACK);
+  tft.writeFillRect( sliderButton.x, sliderButton.y, sliderButton.w, sliderButton.h, ILI9341_BLACK);
   tft.writeFillRect( SLIDER_XPOS - 2, SLIDER_YPOS, 4, SLIDER_HEIGHT, ILI9341_YELLOW );
   tft.endWrite();
 


  snprintf( sliderButton.text, sizeof( sliderButton.text ), "%.0f%%", tftBrightness );
  drawButton( sliderButton, ILI9341_BLUE, 0 );
  //set backlight
  ledcWrite( TFT_BACKLIGHT_CHANNEL, map( tftBrightness, 0, 100, 0, backlightMaxvalue ) );
}

    140, 205, 170, 30
  };

  button_t tempArea[numberOfFoundSensors];

  uint16_t channelColor565[NUMBER_OF_CHANNELS];

  if ( tftClearScreen )
  {
    tft.fillScreen( ILI9341_BLACK );
    drawButton( MENU_BUTTON, ILI9341_BLUE, 0 );
    tft.setTextColor( ILI9341_YELLOW, ILI9341_BLACK );
    tft.startWrite();
    for ( uint8_t thisSensor = 0; thisSensor < numberOfFoundSensors; thisSensor++ )
    {
      tempArea[thisSensor].x = 220;
      tempArea[thisSensor].y = 70 + thisSensor * 50;
      tempArea[thisSensor].w = TFT_BUTTON_WIDTH - 20;
      tempArea[thisSensor].h = 30;
      tft.writeFastHLine( tempArea[thisSensor].x, tempArea[thisSensor].y, tempArea[thisSensor].w, ILI9341_GREEN );
      tft.writeFastHLine( tempArea[thisSensor].x, tempArea[thisSensor].y + tempArea[thisSensor].h, tempArea[thisSensor].w, ILI9341_GREEN );
      tft.writeFastVLine( tempArea[thisSensor].x, tempArea[thisSensor].y, tempArea[thisSensor].h, ILI9341_GREEN );
      tft.writeFastVLine( tempArea[thisSensor].x + tempArea[thisSensor].w, tempArea[thisSensor].y, tempArea[thisSensor].h, ILI9341_GREEN );
    }
    tft.endWrite();
    for ( uint8_t thisSensor = 0; thisSensor < numberOfFoundSensors; thisSensor++ )
    {
      int16_t x, y;
      uint16_t w, h;
      tft.setTextSize( 0 );
      tft.getTextBounds( sensor[thisSensor].name, 0, 0, &x, &y, &w, &h);
      tft.setCursor( ( tempArea[thisSensor].x + tempArea[thisSensor].w / 2 ) - w / 2,
                     ( tempArea[thisSensor].y - 10 ) );
      tft.print( sensor[thisSensor].name );
    }
    tftClearScreen = false;
  }

