Adafruit Fomu - ICE40 FPGA Development Board

Only 13mm long, Fomu is a fully open-source, programmable FPGA device that fits inside a USB Type-A port. Equipped with four buttons, an RGB LED, and an FPGA compatible with a fully open-source chain, it is capable of running a RISC-V core.

Fomu offers 128 kilobytes of RAM and ample storage, allowing it to run Python natively. The convenience of its USB port placement makes installation seamless. Despite the complex nature of FPGAs, modern Python tools simplify usage, eliminating the need for specialized training.

Beneath the surface, a RISC-V softcore operates on the FPGA fabric. This emerging processor architecture is set to revolutionize everything from embedded chips to high-performance computing. Fomu’s RISC-V softcore provides an excellent introduction to future architectures.

An FPGA is a reconfigurable piece of silicon. Fomu’s default firmware features a USB bootloader running a RISC-V softcore, with flexibility to load various configurations, such as LM32 and OpenRISC softcores. Users can experiment by adding CPU instructions or hardware blocks, such as advanced LED blink patterns.

With a fully open development process, Fomu is accessible without needing to create an account, sign an NDA, or download large installers. The ICE40UP5K FPGA, supported by an open toolchain, facilitates development from the get-go.

Fomu's FPGA allows for unique possibilities like creating an LED driver to efficiently manage NeoPixels, freeing the CPU for other tasks or conserving power. Users can modify or replace the CPU using a hardware description language, enabling the creation of new instructions, such as fast 64-bit multiplies or random number generators.

Each set includes one fully assembled Fomu, ready to explore endless possibilities in microprocessor design and function.