Getting an FPGA onto a solderless breadboard usually means a bulky dev kit and a proprietary programmer. The Forgix board from Adiuvo Engineering takes a different route, packing an Efinix Trion FPGA and a Raspberry Pi microcontroller into a Teensy-sized module that streams its bitstreams over plain USB, with the loader tooling published as open source.
The board splits work across two chips. Software runs on the Raspberry Pi RP2354, part of the RP2350 family, which carries dual Arm Cortex-M33 cores at 150 MHz alongside a pair of open-hardware Hazard3 RISC-V cores that can be selected in software, plus 520 KB of SRAM backed by an external QSPI PSRAM chip. Custom digital logic lives on the Efinix Trion T8F49 FPGA sitting next to it, offering 7,384 logic elements clocked from an external oscillator. That combination makes the Forgix a compact target for hardware-software co-design: high-speed signal processing, custom peripherals, or RTL acceleration on the fabric, with the MCU handling firmware and I/O.
The module breaks out standard microcontroller interfaces including SPI, I2C, UART, ADC, and USB 1.1 to its header pins, alongside dedicated 3.3V FPGA I/O rails, in the breadboard-friendly Teensy layout. A single USB Type-C connector handles both power and programming, and the board adds a user push button, an addressable RGB status LED, and a Tag-Connect TC2030 SWD footprint for hardware-level debugging of the MCU.
The most interesting piece for tinkerers is the loader. Adiuvo has released the Forge FPGA Loader on Bitbucket, an open-source binary framing protocol and utility with a Python/Tkinter GUI and CLI. Because the FPGA is configured in passive SPI mode (Mode 3), the host streams .hex or .bin bitstreams generated by Efinix's free Efinity toolchain over USB CDC serial, passing them straight through the RP2354 to the fabric. Efinity is available for Linux and Windows, and the Python-based loader runs on either platform without modification, making the full design-to-programming workflow usable entirely on Linux. On Linux, the board enumerates as a standard USB CDC ACM serial device handled by the kernel's built-in driver, so no additional drivers are required. That stream-through design sidesteps the microcontroller's RAM limits entirely, so a full FPGA configuration never has to be buffered in MCU memory first.
The Forgix board is available now for $50 (€46), with full documentation and the open-source bootloader firmware in the Adiuvo Engineering Bitbucket repository.
