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[trickeydan]

Requires:

• Servos - Create Servo Component #42
• GPIO - Create GPIOPin Component #43
• Ultrasound - This may or may not want to be a component. Consider this when we get here.

[kierdavis]

I think canonically ultrasound sensors should be a component; however this may require a rethink of the component API due to how ultrasound sensors are addressed as a pair of pin numbers (trigger pin and echo pin).

[trickeydan]

For ultrasound sensors, we could have a 'virtual' Component. Two GPIOPins can be passed to it in the constructor?

[kierdavis]

yeah. There's no reason why we couldn't have high-level components built on top of low-level components. I'm thinking something like:

class ServoAssembly:
  ...
  def ultrasound_sensor(self, trigger_pin, echo_pin):
    if isinstance(trigger_pin, int): trigger_pin = self.gpio[trigger_pin]
    if isinstance(echo_pin, int): echo_pin = self.gpio[echo_pin]
    return UltrasoundProximitySensor(self._backend, trigger_pin, echo_pin)
  ...
class UltrasoundProximitySensor:
  @property
  def distance(self):
    return self._backend.read_ultrasound_sensor(self._trigger_pin.identifier, self._echo_pin.identifier)

[kierdavis]

Ultrasound isn't implemented in the hardware backend yet. Fortunately this is just a matter of extending the existing SBArduinoHardwareBackend with UltrasoundInterface; pretty much all of the infrastructure is already in place.

EDIT: also need to implement SBArduinoBoard.get_ultrasound(trigger_pin: PinNumber, echo_pin: PinNumber) -> UltrasoundSensor.

[kierdavis]

#365 fixed this.