BB.Reactor

Spark DSL extension for integrating Reactor with the BB robotics framework.

Installation

Add bb_reactor to your dependencies in mix.exs:

def deps do
  [
    {:bb_reactor, "~> 0.1"}
  ]
end

Usage

defmodule MyRobot.PickAndPlace do
  use Reactor, extensions: [BB.Reactor]

  input :pick_pose
  input :place_pose

  # Wait for robot to be ready
  wait_for_state :ready do
    states [:idle]
    timeout 5000
  end

  # Execute movement command
  command :approach do
    command :move_to_pose
    argument :target, input(:pick_pose)
    wait_for :ready
  end

  # Close gripper
  command :grip do
    command :close_gripper
    wait_for :approach
  end

  # Wait for force sensor event
  wait_for_event :gripped do
    path [:sensor, :force]
    timeout 2000
    wait_for :grip
  end

  # Move to place position with compensation
  command :retreat do
    command :move_to_pose
    argument :target, input(:place_pose)
    wait_for :gripped
    compensate :return_home
  end

  return :retreat
end

# Run the reactor
Reactor.run(MyRobot.PickAndPlace, inputs, %{private: %{bb_robot: MyRobot}})

Entities

command

Execute a BB command with safety handling and compensation support.

command :move do
  command :move_to_pose           # The BB command to execute
  argument :target, input(:pose)  # Arguments passed to the command
  timeout 30_000                  # Optional timeout (default: :infinity)
  compensate :return_home         # Optional compensation command for undo
end

wait_for_event

Wait for a PubSub event matching a pattern.

wait_for_event :force_detected do
  path [:sensor, :force_torque]   # PubSub path to subscribe to
  timeout 5000                    # Optional timeout
  message_types [ForceTorque]     # Optional: filter by message type
  filter &MyFilters.threshold?/1  # Optional: custom filter function
end

wait_for_state

Wait for the robot to reach a specific state.

wait_for_state :wait_for_idle do
  states [:idle]                  # Target states (any-of matching)
  timeout 5000                    # Optional timeout
end

Safety Integration

The BB.Reactor.Middleware.Safety middleware can be added to publish reactor errors as BB.Safety.HardwareError events on [:safety, :error]:

defmodule MyRobot.SafeReactor do
  use Reactor, extensions: [BB.Reactor]

  middlewares do
    middleware BB.Reactor.Middleware.Safety
  end

  # ... steps
end

This is a notification bridge - the middleware does not change safety state. Subscribers to [:safety, :error] can implement custom alerting or recovery (including calling BB.Safety.disarm/1 when appropriate). BB's own force-disarm path is driven by the topology supervisor's restart budget, not by reactor errors.

Documentation

• HexDocs
• BB Framework
• Reactor

License

Apache License 2.0