SensorPipeline.lf

# Lab 2 starter: build a two-reactor pipeline.
# A Sensor will produce periodic readings and a Display will consume them.
# Follow the exercises in the lab README. The TODO markers below show where
# each exercise makes its changes. This file compiles as it is.
target Python {
  timeout: 4 s
}

reactor Sensor(period = 1 s, gain=3) {
  timer sample(0, period)

  # TODO (Exercise 2): declare a state variable named `raw`, initialized
  # to 0, to count how many samples have been taken.
  # TODO (Exercise 3): declare an output port named `reading`.
  reaction(startup) {=
    print(f"Sensor started with period {self.period // MSEC(1)} ms and gain {self.gain}.")
  =}

  # TODO (Exercise 3): declare `reading` as an effect of this reaction by
  # changing its signature to: reaction(sample) -> reading
  reaction(sample) {=
    # TODO (Exercise 2): increment the `raw` state variable here.
    # TODO (Exercise 3): replace the print below by producing an output:
    # send the value raw * gain on the `reading` port.
    print("Sensor sampled.")
  =}
}

reactor Display {
  state received = 0

  # TODO (Exercise 3): declare an input port named `reading`.
  # TODO (Exercise 3): add a reaction triggered by `reading` that increments
  # `received` and prints the received value and the elapsed logical time
  # in milliseconds.
  reaction(shutdown) {=
    print(f"Display received {self.received} readings in total.")
  =}
}

# TODO (Exercise 4): instantiate a Sensor named `s` and a Display named
# `d`, then connect the Sensor's output port to the Display's input port.
# TODO (Exercise 5): give `s` a period of 500 ms at instantiation and
# predict how many readings the Display will report.
# TODO (Exercise 6): change the timeout above to 2 s and predict again.
main reactor SensorPipeline {
}