Bitmerse, a product-engineering firm, launched its Romu campaign on Crowd Supply on October 13, 2026. Romu is a microcontroller board built around Raspberry Pi's RP2354A that fits entirely inside a USB Type-A plug, with no cable and no headers, and it ships with MicroPython preloaded. Bitmerse produces it in Ahmedabad, India. Its GitHub repository sums it up as "A Raspberry Pi board that fits inside your USB port."
The campaign is not yet funded. As of October 20, 2026, it had raised $1,080 of its $5,000 goal (22%) from 12 backers, and pledges start at $40. Funding closes on November 26, 2026, at 4:00 PM PST (00:00 UTC on November 27), 37 days from October 20. Crowd Supply gives an estimated ship date of April 26, 2027, which is an estimate, not a commitment.
The hardware
The Crowd Supply campaign page lists:
- MCU: Raspberry Pi RP2354A, dual Arm Cortex-M33 or dual Hazard3 RISC-V cores at 150 MHz
- Memory: 520 KB SRAM, 2 MB embedded flash
- USB: native USB 2.0 Full-Speed through the Type-A plug itself
- Power: 5V from USB, regulated to 3.3V onboard
- On board: one RGB LED, one capacitive touch button and a boot button
- Programming and debug: USB DFU or SWD test points; UART TX/RX test points
- PCB: 15.5 mm × 12 mm × 1.65 mm
- Enclosure: preinstalled 3D-printed protective shim
CNX Software's write-up adds that the 2 MB is stacked, in-package flash, that the Cortex-M33 cores support Arm TrustZone and secure boot, and that the Hazard3 cores implement RV32IMAC with the Zba, Zbb, Zbs, Zbkb, Zcb, Zcmp and Zicsr extensions. It also points out the obvious trade-off of the form factor: Romu "doesn't come with any GPIO." Everything the board does, it does over USB, the LED and the touch pad.
The optional Programming & Debugging Jig is a tool-free pogo-pin fixture. It connects to a computer over USB-C and breaks out a standard 20-pin JTAG connector for SWD plus UART RX/TX, so the test points can be used without soldering.
Where it fits
Romu joins a small family of open-hardware boards that live inside a USB port, and the campaign page compares it directly with three of them: Tomu (EFM32HG309, Cortex-M0+ at 25 MHz, $25), Somu (STM32L432KC, Cortex-M4 at 80 MHz, $35) and Qomu (EOS S3 with an eFPGA, $49). On Bitmerse's figures, Romu has the most SRAM of the four at 520 KB and the highest CoreMark score, 615.0, against 61.5 for Tomu and 283.2 for both Somu and Qomu. It is also the only one of the four that the comparison lists with MicroPython preloaded and a debug jig, though at $40 it costs more than Tomu or Somu. CNX notes that Romu is the first "omu" board from Bitmerse, whose earlier Crowd Supply projects, WiSer and bPiShift, were funded and shipped, according to the campaign page.
Pledges, manufacturing and open files
Crowd Supply lists four pledge levels:
- Romu: $40
- Romu 3 pack: $90
- Romu with Programming & Debugging Jig: $65
- Romu 3 pack with Programming & Debugging Jig: $115
Shipping is extra: $8 within the US and $18 worldwide. Elecrow handles most of the manufacturing, and Bitmerse says it has already built and tested a small batch. Finished units go to Crowd Supply, which ships through its logistics partner Mouser Electronics.
Romu is open hardware. The repository licenses documentation under CC BY-SA 4.0, hardware files under CERN-OHL-P-2.0 and software under MIT. The campaign lists schematics, PCB design files, the bill of materials, the enclosure STL files and example scripts among the released materials. Demo firmware covers a keystroke macro, passkey authentication and a website launcher, and the repository already hosts a FIDO2 security-key firmware project. CNX also lists a dino game among the examples on GitHub.
What It Means for Makers
Romu is aimed at people building things that are USB devices first: macro keys, FIDO2/U2F security keys, USB MIDI controllers, custom HID devices and small USB sensors or status lights, all use cases the campaign names. With no GPIO pins, it is not a fit for projects that need to drive external hardware.
Getting started is meant to be low-friction. Bitmerse says Romu works in the Thonny IDE straight out of the package, "with no drivers or external programmer needed," and the repository documents how to enter bootloader mode for MicroPython updates, other firmware or recovery. Anyone who expects to use SWD or the UART regularly should budget for one of the jig tiers rather than working the test points by hand.
The usual crowdfunding caveat applies: a pledge is a pre-purchase of a product that does not exist at volume yet, and delivery depends on the campaign reaching its goal and on production staying on schedule. Backers who want one should pledge before the November 26 deadline; the published hardware files are there for anyone who wants to build or modify the board themselves.
