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Getting started

This is the path from a box of parts to a robot that maps a room and drives it. Steps 1 and 2 run anywhere; from step 3 on you need the hardware, so they run on the Pi.

If you want to try the software before building anything, skip to Simulation — it needs no hardware and runs the same launch files.

Prerequisites

  • The robot, assembled. Printing, assembly and wiring are covered in Printing & assembly and Wiring & power; the parts list is the BOM.
  • A Raspberry Pi 5 running 64-bit Linux. Ubuntu 24.04 and Raspberry Pi OS Bookworm both work — the Raspberry Pi Imager route is Raspberry Pi OS (other) → Raspberry Pi OS Lite. To hand a clean Pi its identity, network and build in one shot instead, render a cloud-init image with pixi run provision (see the fleet runbook).
  • pixi installed. Everything else — ROS 2 Jazzy, Nav2, the drivers — is pulled in by pixi. There is no system ROS install.

1. Clone

git clone --recurse-submodules https://github.com/ClachDev/Mote
cd Mote

Forgot --recurse-submodules? pixi run submodules fetches them afterwards.

2. Build

pixi run build

Artifacts land in build/, install/ and log/, all git-ignored. If a build complains about CMakeCache.txt naming the wrong source directory (a path rename, usually), delete build/ and build again.

Built on your workstation? Copy it to the Pi with pixi run sync, or pixi run -e dev sync-watch to keep it copying on every save. Launch files, config and Python go live without a rebuild (colcon --symlink-install); only C++ needs pixi run build again on the Pi.

3. Set up the Pi

One time, on the robot:

pixi run setup

That installs the udev rules that give the hardware stable names (/dev/mote_servos, /dev/mote_lidar, /dev/mote_camera), disables WiFi power save, and installs the systemd units. The units are installed but not enabled — autostart would flatten the battery on a desk. Opt in when the robot lives on the floor:

sudo systemctl enable --now mote-bringup mote-health

See Bringup & reliability for what those services do, and what the pre-flight self-check refuses to start without.

4. Configure the servos

The drive wheels are expected at servo IDs 7 (left) and 9 (right) at 1 Mbaud. Fresh Feetech STS3215 servos all ship as ID 1, so assign IDs before first use, connecting one servo at a time when prompted:

pixi run setup-ids

The servo bus tools cover the rest of the bus utilities — pinging, swapping IDs, and calibrating velocity_scale.

The arm is on the same bus

An SO-101 arm's six servos share the wheels' bus at IDs 1–6, so it needs no extra electronics — and no udev rule of its own. A serial port has no kernel-level exclusion, so exactly one process may hold it, and that process is the controller manager. See the arm docs.

5. Map a space

The stack runs in two phases: build a map with SLAM, then drive it without.

pixi run mapping   # bringup + SLAM
pixi run teleop    # in another terminal: drive it around
pixi run save-map  # save the map + posegraph into the active site

Instead of driving it yourself, pixi run explore covers the space autonomously — run it on the Pi, so a WiFi drop cannot end the mission.

save-map writes an immutable map revision into the active site's floor, runs a cleaning pass over it, and validates it. Sites, maps & zones explains what a site bundle is, why maps are revisions, and how to teach named places.

6. Drive the map

pixi run robot     # bringup + Nav2 against the saved map

Send goals from RViz (pixi run rviz, which selects the dev environment), or connect a Foxglove desktop to ws://<robot-id>:8765 — the bridge is part of the base bringup, and the shipped layout has teleop, a map view and the pause control. Teleop always wins over Nav2 without cancelling the mission; the drive path explains the arbitration.

Once places are named, missions become commands:

pixi run tasks     # the behaviour-tree task layer, alongside `pixi run robot`

pixi run -- ros2 topic pub --once /task/command std_msgs/msg/String \
  "{data: goto kitchen}"

See Missions for the fetch and goto grammar.

At this point you have a working robot stack: maps, SLAM, Nav2, teleop and missions. From here:

  • Perception turns the webcam into obstacles Nav2 can see and objects a mission can fetch — with the heavy models on an inference server rather than the Pi.
  • The fleet layer puts several robots behind one dashboard, with enrollment, dispatch and a shared map registry.
  • Simulation runs all of it against Gazebo.

Contributing

A pre-commit config handles hygiene checks, shell linting and Python error checking. Wire it in once per clone:

pixi run lint-install   # into .git/hooks
pixi run lint           # or across the tree by hand (~1 s)

To work on these docs:

pixi run docs           # live-reloading site on http://127.0.0.1:8000
pixi run docs-build     # what CI runs, with --strict

AI aided contributions are welcome, but only if you can explain and vouch for every change.