MiniAnki

This pocket-sized device helps me practice Chinese characters passively using an e-ink display. When a character appears, I respond with one of three buttons to indicate how well I remember it (Hard, Good, or Easy). The system uses spaced repetition to show difficult characters more frequently. I can easily update my flashcard collection by connecting to my computer via USB or microSD card, keeping my portable practice in sync with my main Anki deck.

In this video, I show briefly the operation of the flashcard system. Specifically, the ability to display chinese characters and clicking any button to reveal the flashcard. After the flashcard has been revealed, clicking red yellow or green willd etermine how long until you see that same flashcard again.

Process

The process of fitting everything into this compact Anki flashcard device took much longer than expected. Although simple on breadboard it became a spatial puzzle within the box. I had to cut several wires to make them shorter and use multiple connection terminals to save space. An unexpected challenge arose when I accidentally damaged the original e-ink display during assembly, meaning I had to resolder connections and install a replacement.

Discussion

A suggestion I'm taking seriously was "Could you make the characters/translations bigger?" While focused on technical implementation, I overlooked this fundamental usability aspect. The e-ink display certainly has sufficient resolution for larger text, and I should have prioritized readability from the beginning. Reflecting on the project, I'm generally satisfied with the outcome but recognize several shortcomings. The physical form factor works well, but I significantly underestimated the complexity of wire management and component arrangement in such a small space. The accidental damage to the original display was frustrating but taught me to be more methodical during assembly.

This project revealed my tendency to underestimate the biggest challenge. Integration. While I'm comfortable getting individual pieces and components to work properly, system-level implementation and getting everything to work together, as well as integration-testing is something I need more practice on. I've learned the importance of planning more thoroughly before assembly and considering physical interactions between components.

Additionally, the project had several software/technical challenges. Working with the e-ink display, especially with refresh timign constraints was difficult.  Furthermore, loading Chinese bitmap fonts created another challenge, as I had to manually pre-load specific character glyphs to prevent rendering delays. Memory management was important to prevent crashed from having several characters.

The spaced repetition system presented its own implementation challenges. I aimed for simplicity while maintaining effectiveness, eventually settling on a system where cards move between difficulty levels based on user ratings. Each difficulty level corresponds to increasingly spaced review intervals (daily, every 3 days, weekly, etc.). 

I expect to build a new version of this project. For these future iterations aside from possibly 3d printing the box and physical form, I would implement other suggestions like adding "a TV knob that shifts the frequency/timeframe for each card" and making the system "a little gamified" with session-based reviews and scoring. I'd also focus on making the device fully self-powered with better battery management.

Technical information

Full code can be found here:
https://github.com/Ireoluwa-A/MiniAnki