Start here: what ShieldSigner is
ShieldSigner is an offline Bitcoin signing device. A separate wallet prepares a transaction; the signer reviews and signs its PSBT, then returns the signed data by QR. Your wallet broadcasts the transaction. The signer does not need a blockchain node or an Internet connection to sign.
This site documents a prototype Luckfox Mini build with a 2.8-inch eight-pin LCD, contact smartcard reader and printed enclosure. Digital design checks pass; physical assembly and electrical qualification remain pending. Start with the test record before ordering.
Which project does what?
| Project | Responsibility | What to use here |
|---|---|---|
| SeedSigner | Original Python Bitcoin signer and QR workflows | Learn the signing model; its Raspberry Pi hardware instructions are a different build |
ShieldSigner application fork, 3rdIteration/seedsigner |
Adds smartcards and other tools to SeedSigner | Application pinned by our build wrapper |
3rdIteration/seedsigner-os |
Operating system and platform integration | Our pinned Luckfox Mini microSD build, using the vendor SDK/Buildroot path |
lightningspore/shieldsigner-dev, this repository |
Carrier PCB, enclosure, reproducible build wrappers and this website | Current eight-pin pill carrier files and guides |
Older seedsigner-luckfox-pico work |
Earlier hardware and porting history | Background; do not mix its board, display or image instructions into this carrier |
A Raspberry Pi image is not a Luckfox image. Luckfox models and flash targets also differ. Follow Buildroot & firmware and the flash workflow for the selected Mini/microSD target and UR2 reader.
Choose a path
- Understand it first: Software features, then wallet and backup concepts.
- Build this hardware: Modular assembly, LCD interface, then enclosure and 3D viewer.
- Use existing hardware: Compile, flash, then first signing exercise.
- Add a card: Card compatibility explains why SeedKeeper and Satochip serve different purposes. A card is optional for the ordinary in-memory signing workflow.
- Something fails: use troubleshooting to identify the failing layer before changing hardware or secrets.
Versions describe different things
The website version is not the firmware version. The current modular PCB release is 0.0.4-dev and enclosure preview is 0.0.1-dev. Firmware identity comes from the exact OS and application commits, not those labels.
Our build wrapper pins OS e7589465aff172f4f510ad46d18776ccc8d2c203 and application efdd1cfd14e80a076a7e1ae91e9f2270ecbcd44f. On a development device, cat /etc/seedsigner-os-release records the installed OS/application provenance. Compare it with the intended build before assuming a menu or feature is present.
Sources and scope
Reviewed 2026-10-16: official SeedSigner README, ShieldSigner fork README, fork repository map, and platform support. Links pin the reviewed revisions. The fork revision matches our application build pin; upstream documentation describes software support, not successful tests on our carrier. Our local build pins and hardware test record take precedence for this build.
Source: docs/START-HERE.md ↗. Documentation describes reviewed evidence; it does not replace physical testing.