docs: def get_lux_count(lux_byte):
      """ Method to convert data from the TSL2550D lux sensor
      into more easily usable ADC count values.
  
      """
      LUX_VALID_MASK = 0b10000000
      LUX_CHORD_MASK = 0b01110000
      LUX_STEP_MASK = 0b00001111
      valid = lux_byte & LUX_VALID_MASK
      if valid != 0:
          step_num = (lux_byte & LUX_STEP_MASK)
          # Shift to normalize value
          chord_num = (lux_byte & LUX_CHORD_MASK) >> 4
          step_val = 2**chord_num
          chord_val = int(16.5 * (step_val - 1))
          count = chord_val + step_val * step_num
          return count
      else:
          raise SensorError("Invalid lux sensor data.")