Developer Maxime Rivest Open-Sources Riddle: AI-Powered E-Ink Handwriting on reMarkable Paper Pro

According to Beating, developer Maxime Rivest has open-sourced riddle, a project that recreates the interactive experience of Tom Riddle's diary from Harry Potter on the reMarkable Paper Pro e-ink tablet. Users write prompts with a stylus, which automatically fade after input; a large language model then recognizes the image and streams a response that the device writes back by hand, character by character, before fading again.

To achieve smooth "air handwriting" animation with low latency, riddle bypasses system input stacks to capture 4096-level stylus pressure directly via evdev, and intercepts the proprietary e-paper waveform engine to write frames directly to VRAM. The project uses Zhang-Suen skeleton extraction on Dancing Script font to track stroke trajectories, reconstructing handwritten animation. Currently, riddle is tested only on specific reMarkable Paper Pro firmware versions.