Modular Handheld Controller
A fully modular handheld game console. Swappable input modules, swappable front and back plates, swappable SoC and storage, all on a common backplane bus. Our own product, in active development. Open source at launch.
Every handheld is a compromise. Joystick placement, button layout, trigger feel, back-paddle count, haptics, speakers, touchpads: people want different things, and no single device nails all of them. We're building one that does not try. A common backplane bus, twelve swappable modules across the face, swappable front and back plates that mate to whatever module layout you pick, and swappable internals (SoC board, NVMe) for users who want to upgrade compute or storage without buying a new device. Groundplane is designing and building it as our own product, with an open-source release planned alongside the first production unit.
What we're building
- Swappable front plate that mates to your chosen module layout
- Twelve module bays sharing a common backplane bus and interface
- Module library spans joysticks, buttons, triggers, back triggers, touchpads, haptics, and speakers, with room for community modules at launch
- Swappable back plate for grips and custom attachments
- Swappable SoC board so users can upgrade compute and RAM independent of the rest of the device
- Swappable NVMe storage
- 7-inch OLED display, DisplayPort over USB-C, dual USB-C ports, microSD
- 5000 mAh battery
- Hardware, firmware, and the module bus interface released open source at launch
Hard parts
The bus is the product. Twelve module bays sharing one interface puts every module’s electrical, mechanical, and addressing burden through a single connector pattern. We are spending real time on the protocol and the physical mate, because every accessory anyone might ever build sits behind that one design decision.
Modularity vs feel. The first thing you give up when you let users swap parts is the unbroken industrial design of a fixed device. Closing that gap (tolerances, transitions between plates and modules, tactile consistency across modules from different makers) is the design problem driving most of our current decisions.
Thermal envelope across configurations. A swappable SoC means thermals have to hold across a range of compute tiers a user might install, not just a single fixed configuration. We are sizing the system around the upper bound so the lower tiers run cool and the higher tiers stay inside the envelope.
Target specifications
- Form factor
- 7-inch handheld
- Display
- 7-inch OLED
- Modules
- 12 bays on a common backplane bus and interface
- Compute
- Swappable SoC board (compute and RAM upgrade path)
- Storage
- Swappable NVMe plus microSD
- Battery
- 5000 mAh
- Connectivity
- Dual USB-C (DisplayPort alt mode), microSD
- License
- Open source at launch (hardware, firmware, module bus)
- Status
- In active design
Where it stands
In active design. Many of the trade-offs (exact module set, plate and shell aesthetics, the bus protocol details) are still in flux and we are not ready to share specifics. The open-source release of schematics, firmware, and the module bus interface will land alongside the first production unit.
