A browser workbench for the SO-101 robot arm
See it, program it, and let the camera tell it when.
Quick start · First run · User guide · Vision
Slixer runs on a PC beside an SO-101 arm and serves one page to a browser. On it:
- A live 3D model of the arm, built from the SO-101's own CAD, that mirrors the real arm as you move it.
- Programs, recorded by demonstration (move the leader arm, press R) or posed by dragging the model, then rehearsed on a virtual arm and played smoothly on the real one.
- Your bench in 3D. Import STL files of fixtures and labware, place them where they really are, and double-click one to send the gripper to it.
- The camera, with Ultralytics YOLO detecting and outlining what it sees on your GPU, including open-vocabulary YOLOE ("well plate, pipette tip") that needs no training. A program can wait until the camera sees something. Slixer also collects training pictures, with draft labels, for teaching a model your own things.
Three modes keep it clear what the model means: Watch mirrors the arm and never sends anything, Plan is a virtual arm to rehearse on, and Drive moves the real one, speed-limited, with STOP (or Esc) always a keypress away.
leader arm ──radio──▶ follower arm ◀──Wi-Fi──▶ PC running Slixer ◀──▶ browser
(XIAO ESP32-C3) (XIAO ESP32-C3) ▲
│ camera frames
Raspberry Pi + USB camera
The two arms teleoperate each other with no computer at all, over their own radio link. Slixer joins over Wi-Fi: it watches the follower, and can drive it. It doesn't use lerobot's USB connection; the arms run the firmware in this repository.
- uv, which manages Python and the environment:
curl -LsSf https://astral.sh/uv/install.sh | sh - The arms: an SO-101 leader and follower, each on a Seeed Bus Servo Driver Board for XIAO with a
XIAO ESP32-C3, flashed from
so101_leader/andso101_follower/. See the firmware guide. - Linux or WSL2. Under WSL2, turn on mirrored networking so the arm's packets reach it (the firmware guide says how).
- For the camera: a Raspberry Pi with a USB camera, running
pi/camera_stream.py. For YOLO: an NVIDIA GPU with a recent driver (CUDA 13). Without one it runs on the CPU, slowly.
git clone https://github.com/LaingLab/SLIXER.git
cd SLIXER
uv sync --extra vision # or plain `uv sync` without YOLO: the extra brings PyTorch, a few GB
uv run slixer/run.py # then open http://localhost:8000On the camera Pi: uv run pi/camera_stream.py. Then tell Slixer where it is, once:
uv run slixer/run.py --camera <the Pi's address>.
FIRST_RUN.md walks through the first session in order: flashing, lining the model up with your arm, a first program, and the camera.
Keep
--extra visionon everyuv sync. A plainuv syncmakes the environment match the lockfile exactly, so it removes PyTorch and Ultralytics again.uv runnever removes anything.
| slixer/FIRST_RUN.md | the first session, step by step |
| slixer/README.md | the user guide: modes, programs, parts, camera, lining up |
| slixer/VISION.md | YOLO models, open-vocabulary detection, and training your own |
| so101_leader/README.md | the arms' firmware: wiring, flashing, Wi-Fi, calibration |
| CHANGELOG.md | what's changed |
| folder | |
|---|---|
slixer/ |
the app: a FastAPI server and the page it serves (three.js) |
so101_leader/, so101_follower/ |
firmware for the two arms' XIAO ESP32-C3 boards |
pc/ |
Python for your own code: so101_link.py talks to the arm, camera_client.py receives the camera |
pi/ |
the camera streamer, for the Raspberry Pi |
Slixer moves a robot. It's a beta, so go gently the first time it drives your arm.
- STOP (or Esc, which works even while you're typing) ends a program, drops anything still on its way, and holds the arm where it actually is. Switching to Watch, or closing every Slixer tab, lets go of it; switching to Plan keeps holding it.
- In Drive, moves are speed-limited and held to the range the arm was calibrated over. Drive waits for a follower that says it's ready, and a program waits for the arm: it pauses while the arm is out of touch, and stops, holding it, if the arm can't get where it's sent.
- If the page loses Slixer, it says so, and until it reconnects it can't send anything, STOP included. A STOP pressed meanwhile is sent the moment it's back; if the arm must stop sooner, switch off its power.
- Parts are drawn, not felt. The arm doesn't know an imported part is there, and will drive through it.
- The page is served to this PC only, unless you start it with
--host 0.0.0.0, and only Slixer's own page can drive the arm, not another website open in the same browser. The arm's Wi-Fi link has no password of its own: anything on the same network can send it poses. Keep the arm on a network you trust. See SECURITY.md.
uv run pytest # about 160 tests, two minutes, no hardware neededThe tests run against an imitation follower that runs the firmware's own logic (slixer/tests/fake_follower.py)
and an imitation camera (slixer/tests/fake_camera.py), on ports the real arm never uses. The YOLO tests run
when the vision extra is installed and the models are downloaded, and are skipped otherwise.
MIT, © 2026 Laing Lab. See LICENSE.
- The SO-101 model (URDF and meshes) is TheRobotStudio/SO-ARM100, under the Apache License 2.0: see slixer/assets/so101/.
- three.js, vendored in
slixer/web/vendor/, is MIT. - The vision extra installs Ultralytics, which is AGPL-3.0 (as are its YOLO weights). It isn't part of this repository, and the rest of Slixer runs without it.
If Slixer helps your research, please cite it: see CITATION.cff.