Week Six: Balance Bots and Better State Machines
Teaming up with Protolux on a Nerves balance bot, command categories with concurrency limits arrive, mechanically-linked joints get their own sensor, and the docs get a proper structure.
A framework for building fault-tolerant robotics applications in Elixir using familiar OTP patterns.
PubSub, request/response services, lifecycle nodes, parameter systems—ROS2 reinvents what the BEAM already provides. Beam Bots brings robotics to Elixir's battle-tested foundation.
PubSub for inter-node communication
Services for request/response
Actions for long-running tasks
Lifecycle nodes for state management
Parameter system for configuration
Phoenix.PubSub, Registry, process messaging
GenServer.call/3
Supervised Task with progress messages
GenServer with state transitions
ETS
Everything you need to build reliable robot systems, powered by OTP supervision and Elixir's expressive syntax.
~u sigil: ~u(90 degree), ~u(0.5 meter), ~u(10 newton_meter).
This pan-tilt camera mount definition shows how Beam Bots' DSL mirrors physical robot structure. The nesting in the code directly reflects the kinematic chain.
Because it's built on Elixir macros, you can metaprogram your robots—use loops to avoid repetition, or write DSL extensions that transform definitions at compile time.
defmodule PanTiltCamera do
use BB
topology do
link :base_link do
visual do
cylinder do
radius ~u(0.03 meter)
height ~u(0.02 meter)
end
end
joint :pan_joint do
type :revolute
origin do
z ~u(0.015 meter)
end
limit do
lower ~u(-170 degree)
upper ~u(170 degree)
end
link :pan_link do
joint :tilt_joint do
type :revolute
limit do
lower ~u(-45 degree)
upper ~u(90 degree)
end
link :camera_link
end
end
end
end
end
end
Updates, tutorials, and insights from the Beam Bots project.
Teaming up with Protolux on a Nerves balance bot, command categories with concurrency limits arrive, mechanically-linked joints get their own sensor, and the docs get a proper structure.
Reactor sagas arrive for task orchestration, the SO-101 hardware lands, Feetech servo support begins, and the proposals repo lets you see what's coming.
Why we chose Reactor sagas over behaviour trees for robot task orchestration, and what that means for resilience and safety.
This project is made possible by the generous support of our sponsors.