by Radiona.org / Zagreb Makerspace

A powerful, open hardware ECP5 FPGA dev board

View all updates Apr 10, 2020

Now With Support for SynthoWheel Retro Sound!

by Goran Mahovlić

FPGA-driven polyphonic additive synthesizer

As we get closer to the end of our first crowdfunding campaign, we would like to share a rather unique feature of our board with the audiophiles out there. It’s a synth!

We have digitally reconstructed a vintage organ (guess which one!) in the digital interface of ULX3S. With this simulation of a very famous vintage organ’s tonewheel, our lab member EMARD created a polyphonic synthesizer with parameters that are configurable through a MIDI interface.

It is a true polyphonic additive synthesizer, implemented in a parametric VHDL core, with support for realtime performance.

Polyphonic synthesis is inspired by a set of multiple rotating tonewheels with electromagnetic pickups such as those found in a Hammond organ, which has a set of drawbars that mix sine wave harmonics to produce characteristic tonewheel waveforms.

SynthoWheel was not created to reproduce a historical sound, but to generate numerically controlled polyphonic sounds using an FPGA. We are in no way suggesting that it can replace original sound synthesizers and organs.

However, the fact remains that using advanced technology to reconstruct old and obsolete technology allows a wider audience to enjoy that vintage analog synth sound.

Thank you very much for your support. We are looking forward to shipping your boards and seeing what you do with them. (Whether you are an engineer or a musician!)

All the best from the Radiona team!

$139,831 raised

of $15,000 goal

932% Funded! Order Below

Product Choices


Expansion Boards

A set of three expansion boards for ULX3S: one dual-USB board with support for IR send and receive, one Digital Video board for GPDI input or as a second GPDI output, and one OV7670 camera connector.


ULX3S with ECP5 12F

ULX3S development board with a Lattice ECP5 (LFE5U-12F-6BG381C) FPGA. 12k LUTs and a whole lot more.


ULX3S with ECP5 85F

ULX3S development board with a Lattice ECP5 (LFE5U-85F-6BG381C) FPGA. 84k LUTs and a whole lot more.


Radiona.org / Zagreb Makerspace

Radiona.org / Zagreb Makerspace works to enhance the visibility of makers' open source culture and sustainable production, as well as to help connect all possible fields of Science, Technology, Engineering, Art, and Mathematics (STEAM).


Marko Zec

Goran Mahovlić

Deborah Hustic

Damir Prizmić

Marko Jovanović

Boris Vidošević

Marvin Sinister

Igor Brkić

Mato Ilijic

Zvonimir Domazet



Components and Hardware Sourcing


Electrical Engineering

See Also

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