Fomu fits entirely inside a standard USB Type-A slot, except for a small area that pokes out to give you access to four copper pads. There is one RGB LED that lights up the case and is fully user-controllable. The main chip is an FPGA with about 5000 LUTs, enough for a CPU with some room left over.
FPGA: Lattice ICE40UP5K
Speed: 48 MHz external oscillator
RAM: 128 kB RAM for a soft CPU¹
Storage: 1 MB SPI flash²
Connectivity: USB 2.0 FS (12 Mbps)
LEDs: One RGB
¹: The FPGA has 1024 kilo-bits of memory available. A separate block of memory is used for things like the processor register file, in addition to temporary memory for things like USB buffers. The CPU can use 64 or 128 kilobytes of memory, depending on configuration. ²: This is the minimum configuration amount – more may be available in the final version.
³: Fomu has four copper pads near the edge. We have not yet validated any capacitive touch solutions.