PWMLed: better logging, building LED on activation.

        self._bcm_pin = SETTINGS.pwmled.get('bcm_pin', default=None, cast_to_type=int, ge=0, le=27, allow_none=True)

        self._frequency = SETTINGS.pwmled.get('frequency', default=100, cast_to_type=int, ge=10, le=10000)

        self._pwmled = None

        self._active = False

        self._rebuild_pwmled()

    def _rebuild_pwmled(self):

        old_value = 0.

        if self._pwmled is not None:

            if not self._active or self._bcm_pin is None:

                _log.info('Disabling PWM led.')

            else:

                old_value = self._pwmled.value

            self._pwmled.off()

            self._pwmled = None

        if self._bcm_pin is not None:

            _log.debug('Rebuilding PWM led on pin %d with frequency %d.', self._bcm_pin, self._frequency)

        if self._bcm_pin is not None and self._active:

            _log.info('Rebuilding PWM led on pin %d with frequency %d.', self._bcm_pin, self._frequency)

            self._pwmled = PWMLED(self.bcm_pin, frequency=self.frequency, initial_value=old_value)

        else:

            _log.debug('Disabled PWM led.')

    def __enter__(self):

        self._active = True

        self._rebuild_pwmled()

        return self

    def __exit__(self, exc_type, exc_val, exc_tb):

        self._active = False

        self._rebuild_pwmled()

    @pyro_expose

    @property