Three Open Hardware Projects to Explore in KiCad

The best part of finding an open hardware project is being able to look beyond the photos. A schematic lets you follow the circuit, while a board file shows how the designer has made room for it.

This selection covers a compact USB board, a handheld calculator, and a security-key concept. Each gives makers something different to investigate in KiCad. All three are early designs, so read the authors’ status notes before planning a build.

IV-DCY keeps the USB hardware small

IV-DCY is a compact USB reference design built around an STM32F042. The two-layer board includes USB-C, ESD protection, a boot button for entering the chip’s USB DFU bootloader, and an SWD header. Its firmware is intended to provide a virtual serial port with simple text commands.

That narrow scope makes it an interesting design to read alongside the firmware. You can follow the USB connection through the schematic without first untangling a much larger application. Despite the name, IV-DCY contains no current-voltage measurement hardware.

The repository includes editable KiCad 9 files, plus the scripts used to generate the schematic and layout. The author reports software checks, but no board has been fabricated or tested. Real USB enumeration and compliance testing are still outstanding, and the proposed USB product ID has not been assigned.

Explore the files: KiCad schematic, PCB layout, and hardware license.

NeoCalculator puts a handheld on the drawing board

NeoCalculator Rev A combines an ESP32-S3 with a 50-key matrix, a display connector, and lithium-ion charging and power circuitry. Its two-layer board is a useful place to look at how the pieces of a handheld device fit together.

The release includes KiCad 10 schematic and PCB sources. Enclosure files are available as STL meshes, but the editable enclosure CAD sources are not included.

There is an important catch: the author explicitly asks readers to wait before ordering PCBs or printing the case. This is alpha hardware. The schematic still names an earlier USB-C connector, while the layout and bill of materials use its replacement. That mismatch is exactly the kind of detail worth resolving before sending files to a board house.

If you enjoy keypad design or the mechanical puzzle of a handheld, there is plenty to inspect here. Treat the release as a design review, with the project’s warning firmly in view.

Explore the files: KiCad schematic, PCB layout, and hardware license.

Cardea Key opens up an early security-key design

Cardea Key’s Rev A hardware draft brings together an RP2354A microcontroller, an NXP SE051C2 secure element, and connections for an external fingerprint sensor. The KiCad 10 project includes a schematic and a four-layer PCB placement draft.

The placement is only a beginning: the board has not been routed, manufactured, or validated. The author says to wait for validation of the full prototype before manufacturing it.

The firmware status deserves equal attention. It is experimental and unaudited, and secure-element support has only been tested against a simulation, not a real SE051C2. This revision is a subject for investigation, not a security device to depend on for protecting accounts.

For makers curious about how a secure element and a microcontroller are connected, the published schematic gives that discussion something concrete to work with. Keep the hardware design and the evidence for its security separate when reading it.

Explore the files: KiCad schematic, PCB placement draft, and hardware license.

Start with the source files

All three projects identify their hardware designs as CERN-OHL-S-2.0 licensed. Check each project’s licensing notes before reusing material; firmware and third-party components can have different terms.

An unfinished design can still be worth opening. Pick the project closest to something you want to understand, follow a signal through the schematic, and compare it with the board layout. You may find a useful idea, or a question that helps the next revision.

source https://blog.tindie.com/2026/11/three-open-hardware-projects-to-explore-in-kicad/