Description
The Grünstahl USB-C dongle provides long-term storage for 2048 bytes of text/data.
Also see Blaustahl and Kaltstahl for more storage and features.
Note: This is a new product and the hardware/software are still under development. Final appearance may have minor differences.
Estimated to ship in H2 2026.
Features
- USB-C plug with USB HID interface
- Open-source software for data access
- 2KB (16Kbit) Ferroelectric RAM
- Lifespan: 95 years @ +55C, over 200 years @ +35C
- Endurance: 10^12 read/write cycles @ +85C
- CH32V003 RISC-V MCU @ 48MHz
- Green LED
- Supports FRAM write protection via solder jumper
- Supports data recovery via pads on reverse side
- Includes 3D-printed PLA plastic case (color/appearance may differ from photo)
- Board dimensions: ~16mm x ~16mm x 0.8mm
Use Cases
- Password storage
- Cryptocurrency private key storage
- Note/list storage
- Geocaching
- Time capsules
- FRAM development board
Resources
- Schematics, firmware, documentation and 3D-printable case will be made available on GitHub
Origin
- Designed in Germany
- PCB manufactured and assembled in China
- PLA enclosure manufactured and assembled in Germany
- Tested, packaged and shipped from Germany





