Technology
Fomu development board embeds programmable FPGA hardware inside standard USB port
The compact device features a Lattice chip and boots a RISC-V softcore directly from a USB connector.
The short version
- Fomu is a programmable development board built to fit entirely within a standard USB Type-A port.[Hacker News]
- The hardware runs on a Lattice ICE40UP5K FPGA configured by default with a RISC-V softcore bootloader.[Hacker News]
- Hardware development spans three validation stages ahead of planned production in China, with capacitive touch support still pending validation.[Hacker News]
Key facts
- Fomu is designed to fit inside a standard USB Type-A port while exposing four external copper pads.[Hacker News]
- The board is powered by a Lattice ICE40UP5K FPGA containing approximately 5,000 LUTs and 1024 kilobits of memory.[Hacker News]
- Fomu's default firmware provides a USB bootloader running a RISC-V softcore, with alternative softcore compatibility including LM32 and OpenRISC.[Hacker News]
- The project follows EVT, DVT, and PVT hardware validation stages with manufacturing planned in China.[Hacker News]
- The design validation board compresses the hardware into a USB form factor via a four-layer blind-buried via PCB and a WLCSP chip package.[Hacker News]
What remains uncertain
- Capacitive touch functionality for the four exposed copper pads has not yet been validated by developers.[Hacker News]
- Developers noted that a hand-assembled two-layer Hacker Version may face long-term reliability issues and susceptibility to mechanical stress.[Hacker News]
Sources
Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.