CAN Commodo
Status: in development, expected for january 2027
Handlebar controls and throttle, published on a CAN bus. One bus, one connector, an arbitrary number of inputs.
Why not just buy it?
Barrier 3: sold only as a closed system.
E-bike controls are the visible end of the closed drive system, and they are cheap and plentiful — as long as you want exactly what the vendor imagined. A throttle is an analogue signal into a controller that expects exactly that throttle. Displays speak undocumented protocols to a specific motor controller. Adding an input the vendor did not anticipate (a mode selector, a turn indicator stalk, a regeneration control, a data logger) become a reverse engineering challenge.
Car suppliers partially solved this decades ago with CAN. but there you are still stuck with NDA and lack of documentation for each modules.
So the gap is not the buttons. Buttons are trivially available. The gap is a documented bus that anything can join.
Why a bus, on a vehicle this small
It looks like over-engineering for a handlebar with a few buttons. The argument is about what happens next.
Every input added to an analogue harness is another wire the length of the vehicle, another connector, another failure point, and another change to the controller. On a bus, an input is a node: it joins, announces itself, and all change are software only.
It is also what makes the vehicle measurable. The logbook-and-GPS validation method described in Chapter 2 needs vehicle data, and a bus means a logger is just another node rather than a wiring harness modification.
What happens when the bus fails
The obvious objection to putting controls on a bus is the failure mode: bus down, everything down. On this vehicle that objection does not hold, because nothing safety-critical is on the bus in the first place.
Braking and steering are mechanically independent. Both are mechanical paths from the rider’s hands to the wheel, with no electronics anywhere in the load path. The bus can fail completely and the rider retains full braking and full steering authority.
Propulsion fails safe on a watchdog. The motor controller expects a throttle command at a regular interval. If none arrives within roughly one second, it cuts power. This is standard practice on electric vehicles the vehicle stops accelerating and coasts, while the rider keeps every control they need to bring it to a stop.
So the worst case of a total bus failure is a vehicle that will not accelerate, on the roadside, with working brakes and steering.