text: """Support for Qwikswitch Sensors."""
  import logging
  
  from pyqwikswitch.qwikswitch import SENSORS
  
  from homeassistant.core import callback
  
  from . import DOMAIN as QWIKSWITCH, QSEntity
  
  _LOGGER = logging.getLogger(__name__)
  
  
  async def async_setup_platform(hass, _, add_entities, discovery_info=None):
      """Add sensor from the main Qwikswitch component."""
      if discovery_info is None:
          return
  
      qsusb = hass.data[QWIKSWITCH]
      _LOGGER.debug("Setup qwikswitch.sensor %s, %s", qsusb, discovery_info)
      devs = [QSSensor(sensor) for sensor in discovery_info[QWIKSWITCH]]
      add_entities(devs)
  
  
  class QSSensor(QSEntity):
      """Sensor based on a Qwikswitch relay/dimmer module."""
  
      _val = None
  
      def __init__(self, sensor):
          """Initialize the sensor."""
  
          super().__init__(sensor["id"], sensor["name"])
          self.channel = sensor["channel"]
          sensor_type = sensor["type"]
  
          self._decode, self.unit = SENSORS[sensor_type]
          if isinstance(self.unit, type):
              self.unit = f"{sensor_type}:{self.channel}"
  
      @callback
      def update_packet(self, packet):
          """Receive update packet from QSUSB."""
          val = self._decode(packet, channel=self.channel)
          _LOGGER.debug(
              "Update %s (%s:%s) decoded as %s: %s",
              self.entity_id,
              self.qsid,
              self.channel,
              val,
              packet,
          )
          if val is not None:
              self._val = val
              self.async_write_ha_state()
  
      @property
      def state(self):
          """Return the value of the sensor."""
          return str(self._val)
  
      @property
      def unique_id(self):
          """Return a unique identifier for this sensor."""
          return f"qs{self.qsid}:{self.channel}"
  
      @property
      def unit_of_measurement(self):
          """Return the unit the value is expressed in."""
          return self.unit
  