by Sutajio Kosagi

An FPGA board that fits inside your USB port

View all updates Feb 18, 2019

Fomu EVT Board Shipping

Greetings backers! With the crowdfunding portion of the campaign over, it’s time for us to work on the Fomu firmware. We’re using EVT boards for development, and the final revision of the EVT hardware just came in.

If you backed the "Fomu EVT Board" tier, you’ll be receiving your very own EVT hardware. You can use this to follow along with the development of firmware, or do your own thing and develop something entirely different.

Since we don’t yet have Fomu firmware, you can’t use them as USB devices yet. However, we have basic demos working for communicating with the FPGA, and thanks to the Raspberry Pi these Fomu boards can’t be bricked.

The Fomu EVT3 hardware has a URL printed on the front in silkscreen: This contains information on how to get started. The overall approach to getting started is:

  1. Download and the latest Fomu Raspberry Pi image
  2. Log in to the Pi with a username of fomu and a password of fomudev
  3. Clone the fomu-tests repository: git clone
  4. Build and load your first blinky demo: cd fomu-tests/blink && make && fomu-flash -f blink.bin

We’re working on examples of how to build a Risc-V CPU and communicate with it using the Raspberry Pi’s serial port, and we’re still working on solidifying the USB firmware that will eventually be loaded.

If you have questions or want to drop by to chat, we’re on #tomu on Freenode. Stop by and say hello, or ask a question. Thanks for supporting us!

$67,541 raised

of $10,000 goal

675% Funded! Order Below

Product Choices



An FPGA for your USB port! Includes one pre-flashed Fomu and a plastic case.


Fomu EVT Board

An EVT board revision is used to validate the schematic is correct, and to help develop the software. This EVT board is what we'll use to develop the USB stack and to make sure we've got the power and other hardware parts wired up right. Designed to mount onto a Raspberry Pi to upload a bitstream and debug the CPU.This is a limited-time production board, and won't be produced after the few remaining sell.


Sutajio Kosagi

Sutajio Ko-usagi supports and produces open hardware products designed by bunnie and xobs.

Sean Cross

Tim Ansell

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