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peng-zhihui/L-ink_Card

Free

Smart NFC & ink-Display Card

FreeFree tier
Type
Open Source
Visit Website GitHub (38 stars)

About peng-zhihui/L-ink_Card

L-ink Card is an open-source mini NFC smart card designed to address common issues with personal IC cards. It combines a STM32L051 microcontroller, an ST25DV NFC chip, and a 200x200 monochrome e-ink display. The card supports emulating multiple IC cards by integrating multiple UID chips that share the NFC antenna, with physical dialing to switch between them. A companion Android app allows customization of the e-ink display content. The project includes hardware design files (Altium Designer), firmware source code (C, with Clion and Keil project files), 3D models for printing an enclosure, and a custom DAP-Link debugger. It is licensed under GPL-3.0.

Key Features

NFC-enabled smart card using ST25DV for energy harvesting and communication
200x200 monochrome e-ink display for customizable visual content
Multi-card emulation via multiple UID chips with mechanical dial selection
Open-source hardware (PCB, schematics, 3D models) and firmware (C, STM32L0)
Companion Android app for display content customization
Supports PM3/PN532 for copying existing IC cards onto the device
GPL-3.0 licensed

Pros & Cons

Pros
  • Fully open-source hardware and software, allowing modifications and improvements
  • E-ink display provides a persistent, customizable visual indicator without power
  • Supports multiple independent cards using physical switching without reprogramming
  • Companion Android app simplifies display content customization
  • Well-documented with BOM, gerber files, 3D print files, and build instructions
Cons
  • Card selection relies on physical switches, limiting scalability for many cards
  • Current design uses ST25DV (ISO 15693), cannot directly emulate common ISO 14443 MIFARE cards without additional hardware
  • Android app UI is basic and described as needing redesign
  • Requires external tools (PM3/PN532) to copy existing IC cards onto the device
  • E-ink display is monochrome (planned color upgrade in future version)

Best For

Consolidating multiple IC cards (e.g., access, transit) into one physical devicePersonalized NFC card with e-ink display for showing custom logos or textsLearning and prototyping NFC, e-ink, and STM32 embedded systemsDIY replacement for traditional IC cards with a customizable interface

FAQ

Does L-ink Card support direct emulation of MIFARE (ISO 14443) cards?
No. The ST25DV chip only supports ISO 15693. IC card emulation is achieved by integrating separate UID chips that share the NFC antenna; each chip represents a different card.
How do I select which card to use?
A dial/switch (mechanical) is used to change the active UID chip, allowing selection of which card is presented to a reader.
Can I customize the e-ink display content?
Yes, a companion Android app is provided to customize the content shown on the e-ink display.
Is the project open source?
Yes, the entire project is open source under the GPL-3.0 license, including hardware design files, firmware, Android app, and 3D models.
What tools are needed to use or modify the L-ink Card?
Building the card requires PCB fabrication (gerber files), soldering components (BOM provided), and a debugger (ST-Link, J-Link, or the included DAP-Link design). A 3D printer is optional for the enclosure.