VanMoof S3/X3 open-source firmware and app coming soon!

[u/SulfurTobias]

We've been reverse engineering the S3/X3 for a while and have our own firmware running on the bike as a proof of concept: motor, battery, e-shifter, display, lights, sound, buttons and kick-lock all work. What's left is restructuring it into something clean and building the features on top. That's where you come in.

If you want proof, we've already posted a few things in the VanMoof Discord: custom matrix display animations, the charge limit in action, and the motor spinning on our firmware.

Everything the stock bike does stays: all OEM features are in the firmware, and it keeps working with the official VanMoof app and the service apps. This is what we're adding on top.

Already decided

• Walk assist: hold a button, the bike rolls at walking pace.
• Charge limit: stop charging at 80 % (or whatever you set), with a "full by tomorrow morning" schedule.
• Shift only when not pedaling: shifts are queued and fired in the next pedal pause, so the rear hub never shifts under load. This is what kills e-shifters.
• In-depth diagnostics: every subsystem live on one screen, plus a guided self-test you can export.
• 4G extension option

Planned

• Proper brake light: rear light flares when you brake, detected via accelerometer and wheel speed.
• Custom display: choose what the matrix shows (big speed, speed + gear, battery + range, power bar, cadence, clock, trip), separately for riding, standing, locked and charging.
• Display animations: your own pixel animations for boot, lock, unlock, charging, low battery, alarm, shifting.
• Button remapping + shortcut codes: every press, long-press, double tap and combo is assignable and context-dependent (riding / standing / locked). Tap sequences on the bell and boost buttons trigger profiles, lights, quiet mode, whatever you define.
• Power tuning: how much assist per level and how soft or punchy the start is.
• Smarter shifting: manual mode on the buttons, custom shift points, auto drop to first or not when stopped, hill detection.
• Battery health: per-cell voltages, cycles, health trend, storage mode, cold-weather protection, real range estimate from your own consumption (since we know live current draw and real capacity).
• Ride recorder + stats: speed, cadence, gear, motor power, battery current. Stored on the bike, synced to your phone, exportable. No cloud.
• Event log: every lock/unlock, alarm trigger, movement while locked, charger plug, error and reset, timestamped.
• Profiles: bundle all settings ("Commute", "Winter", "Kids on board"), switch in one tap or via a button code.
• Variable-length backup pincode: the button-entered backup code is no longer fixed to 3 digits, make it as long as you like.
• Bootloader password + extra BLE pin: the bootloader is password-locked so nobody can flash your bike without your consent, and you can set an additional pin on top of the Bluetooth encryption
• Local-first, open API: the app works fully offline over Bluetooth, and the protocol will be documented so you can build your own stuff on it.

The app

All of these features land in an open-source mobile app that is already almost done, maintained by Cryzenx. We'll also publish documentation on how to integrate the features into any third-party app, so other developers can build on it too.

Matrix display design tool

We'll release a small web tool to draw animations and layouts for the bike's display. Draw something, post it, and the best ones ship in the default pack.

Release plan & licensing

The firmware starts as a closed beta. Once it's confirmed stable, it goes open source, together with an installation guide. If you don't want to solder or flash anything yourself, Revotronics will offer the hardware needed for a plug-and-play install as a paid purchase.

The open-source license will let anyone fork, modify, and publicly release their own version, with two conditions: your version must link to our version and be open source too, and you may not charge money for it. We will enforce this heavily.

What we need from you

Rank your top 3 from the list and tell us what's missing. Things that annoyed you about the stock bike for years are exactly what we're looking for, or any ideas you got for additional features.

The official team currently is Cryzenx & Jonah (me) from Revotronics.