Tracked driving
Browser and gamepad control for differential drive. Sequence-driven overrides for choreographed movement.
Dora-based control stack for a custom WALL-E robot
A modular robot system running on a Raspberry Pi CM4 with tracked drive, SC-series serial servos, on-board audio, animated eye displays, a live USB camera with face tracking, and a phone-first HTTPS web interface. Built with the Dora dataflow framework.
Need the real thing?
Open the node reference instead of reading vague summary boxes.
The landing page stays compact. The actual per-node details, responsibilities, I/O, and hardware assumptions now live in a dedicated node docs page.
Capabilities
What the robot can do
Servo animation
SC-series servos for head, arms, and door. Animated eye displays for expression. All controllable via the web UI.
Showtime sequences
Pre-built action sequences coordinate servos, tracks, audio, and eyes into gestures, reactions, and idle behavior.
Camera & face tracking
Live camera feed via go2rtc, snapshot gallery, and optional face-follow mode for automatic head tracking.
Servo diagnostics
Live status, model data, EEPROM config, cloning, reset, and calibration tools for every servo on the bus.
Power monitoring
INA226 telemetry: voltage, current, power draw, state of charge, estimated runtime, low-battery shutdown.
Architecture
Node overview
The system is split into focused nodes wired together in
dataflow.yml. Each node owns one hardware area or concern.
For the fuller reference, use the dedicated node docs page.
| Node | Role | Description |
|---|---|---|
| web | Interface | HTTPS app, WebSocket bridge, camera proxy, photo gallery, gamepad bridge, face-follow coordination |
| sequence | Choreography | Timed multi-node action sequences for scenes, dances, gestures, and idle behavior |
| waveshare_servo | Actuation | Servo discovery, movement, diagnostics, calibration, cloning, and config for the SC bus |
| tracks | Drive | Differential drive via serial to the RP2040 motor controller |
| audio | Sound | Sound playback, volume control, current-sound state reporting |
| eyes | Display | Eye image/GIF control and available-image discovery on networked ESP32S3 displays |
| power | Monitoring | INA226 battery telemetry (voltage, current, SoC) and low-battery shutdown |
| config | Settings | Shared settings persistence and update propagation across nodes |
Reference BOM
Hardware this stack is built around
Not a universal shopping list. These are the specific parts the software assumes. Some are tightly coupled, others are flexible.
Compute & control
- Raspberry Pi CM4 — main Linux computer
- Waveshare CM4-NANO-B — carrier board
- Seeed XIAO RP2040 — track firmware controller
- 2× AXFEE mini USB hubs — stripped to fit
- QIANRENON 180° USB adapter — housing removed
Motion & expression
- Cytron MD13S — 30V/13A motor driver
- Tracked differential drive — RP2040 low-level control
- Waveshare SC servo controller — USB serial
- SC09-class servos — head, arms, door
- Seeed XIAO ESP32S3 — eye display controllers
Power & audio
- HOOVO 3S LiPo — 2200mAh, 11.1V, 50C, XT60
- INA226 — current/voltage with 0.002Ω shunt
- Pololu S8V9F7 — 7.5V/1.5A step-up/down regulator
- Garosa TPA3110 — 2×15W stereo amplifier
- MMOBIEL MacBook Pro A1706 speakers — repurposed pair
Sensing & media
- USB camera module — OV5693/IMX258, 4K, UVC
- go2rtc — local camera streaming
- Phone-first HTTPS UI — main operator surface
- 8BitDo Ultimate Mobile — reference gamepad
Hard-coded
SC-series servos, RP2040 drive protocol, Cytron MD13S driver, INA226 telemetry, go2rtc camera stack, network-addressable ESP32S3 eye displays.
Flexible
Exact motors, chassis, gearboxes, servo count, gamepad model, and USB camera can vary as long as the software interfaces stay compatible.
Getting started
Prerequisites and basic commands
Python 3.12+
uv
pnpm
Node.js
Dora CLI
# Setup
$ python -m venv .venv
$ source .venv/bin/activate
$ uv pip install -e .
# Run the full stack
$ make run
# Build frontend assets
$ make web/build
# Build / flash track firmware
$ make tracks/build
$ make tracks/flash
$ python -m venv .venv
$ source .venv/bin/activate
$ uv pip install -e .
# Run the full stack
$ make run
# Build frontend assets
$ make web/build
# Build / flash track firmware
$ make tracks/build
$ make tracks/flash
Resources
References and build documentation
Community
Questions, mods, and builder help
GitHub Discussions is the place for questions, troubleshooting, showcase posts, and builder-to-builder help.
Discussions
Ask questions, share mods, compare notes
Build help, remix ideas, photos, videos, experiments, and practical advice from other builders.
Guideline
Discussions only, in English
Discussions are the current public place for maker conversation, troubleshooting, and support around the project. Please keep them in English.
Optional
If you want to say thanks
If this project saved you time and you want to send a small tip, PayPal: apocalip@gmail.com.
Credits & origins
This project stands on other people's work
This robot and this repository do not come out of nowhere. The overall project is heavily rooted in earlier public WALL-E build work, and has been influenced by many mods, remixes, forum posts, build logs, experiments, and shared ideas from the wider WALL-E maker community.
Primary starting point
The overall build is heavily rooted in the work of chillibasket, whose designs and earlier WALL-E build work provided a major starting point for this version.
Mods and remixes in the lineage
These are some of the public remix directions and mods that were definitely part of the path. Some were tried directly, some mainly informed ideas, and almost all of them were eventually reworked further. By now they have generally been adapted or folded into this robot in a changed form.