code: def set_device_brightness(self, val):
          
          # bitshift to scale from 8 bit to 5
          self._chipset_brightness = (val >> 3)
          self._brightness_list = [0xE0 + self._chipset_brightness] * self.numLEDs
          self._packet[self._start_frame:self._pixel_stop:4] = (
              self._brightness_list)
docs: APA102 & SK9822 support on-chip brightness control, allowing greater
          color depth.
  
          APA102 superimposes a 440Hz PWM on the 19kHz base PWM to control
          brightness. SK9822 uses a base 4.7kHz PWM but controls brightness with a
          variable current source.
  
          Because of this SK9822 will have much less flicker at lower levels.
          Either way, this option is better and faster than scaling in
          BiblioPixel.