The ULX3S is a fully open source, compact, robust and affordable FPGA board equipped with a balanced spectrum of extra components

ULX3S-85F v3.1.8

Sold by Intergalaktik d.o.o.


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The ULX3s offers a wide selection of useful features and interfaces that enable it to serve as a broad spectrum module for installation in complex devices. Onboard peripherals such as SDRAM, USB, Digital video out, FM/ASK antenna, ADC and DAC can make it audio/video powerhouse for signal processing and synthesis, motor control or SDR cases. You can emulate arcade machines or retro computers like Minimig (Amiga) or modern systems like F32C (MIPS/RISCV). It has 56 GPIO pins, all routed as differential pairs and a PMOD compatible pinout, opening it to a wide range of expansion options.

ULX3S uses powerful Lattice Semiconductor ECP5 series FPGA chip supported by the latest open-source toolchains. This makes the ULX3S one of the most powerful and desirable platforms for FPGA enthusiasts available today. ULX3S comes equipped with onboard WiFi, display, buttons, LEDs and storage. Flash it using the WiFi connection (over-the-air update), or with one of the bitstreams stored on SD card and browsed by onboard OLED display and buttons. Due to its battery-backed RTC, it can power down completely and wake up only on certain events making it useful for low power applications.

It has been actively developed since 2016 and is the result of collaboration between / Zagreb Makerspace and FER – Faculty of Electrical Engineering and Computing – University of Zagreb, Croatia. ULX3S is being actively used in Digital Logic class at the University of Zagreb Faculty of Electrical Engineering and Computing, Croatia.

Key features

FPGA: Lattice ECP5 LFE5U-85F-6BG381C (84K LUT); RAM: 194 - 669K bits; clock: 2.4 - 62 MHz, I/O: 197 - 365 user programmable
USB: FTDI FT231XS (500 kbit JTAG and 3Mbit USB-serial)
GPIO: 56 pins (28 differential pairs), PMOD-friendly with power out 3.3V/1A 2.5V/1.5A
FLASH: 4–16MB Quad-SPI Flash for FPGA config and user data storage
LEDS: 11 (8 user LEDs, 2 USB LEDs, 1 WiFi LED)
BUTTONS: 7 (4 direction, 2 fire, 1 power button)
AUDIO: 3.5 mm jack with 4 contacts (analog stereo + digital audio or composite video)
VIDEO: Digital video (GPDI General-Purpose Differential Interface) with 3.3V-5V I2C bidirectional level shifter
DISPLAY: placeholder for 0.96" SPI COLOR OLED SSD1331
WIFI+BLUETOOTH: placeholder for ESP-32 (Standalone JTAG web interface over WiFi)
ANTENNA: 27, 88–108, 144, 433 MHz FM/ASK onboard
ADC: 8 channels, 12 bit, 1 MSPS MAX11125
POWER: 3 Switching voltage regulators: 1.1V, 2.5V, 3.3V
CLOCK: 25 MHz onboard, external differential clock input
LOW POWER SLEEP: 5uA/5V standby, RTC MCP7940N clock wake-up, power button, 32768 Hz quartz with CR1225 battery backup
Dimensions: 94 × 51 mm / 3.7 × 2 inch

Links to code and documentation

Documentation (

Code (

Design Files (

Schematics (

Bom (

Certified Open Source Hardware - OSHW HR000011

Shipping policy

All products will be shipped with Croatian national post with tracking no.

The seller

Intergalaktik d.o.o.

Zagreb, Grad Zagreb, Croatia
5 orders since Feb 6, 2024
intergalaktik d.o.o. - research, development, production and distribution open source hardware products.