Make the code physical
The project combines an Adafruit Matrix Portal S3, a 64-by-32 RGB matrix, and a PCF8523 real-time clock. The README describes HOTP generation, configurable code lengths, an optional prefix, and a time hint to help detect clock drift.
The visual symbol is explicitly described as a narrow, nonstandard QR-like subset. That qualifier matters: this project should not be presented as a general QR encoder or a drop-in authenticator for arbitrary services.
Time is a dependency
The documented setup initializes the clock from compile time with a configured offset. It expects UTC for code generation and warns that forcing a local-time offset makes the output incorrect. Local display time with daylight-saving adjustment is listed as unfinished work.
That makes the project useful for discussing how device configuration affects an authentication protocol. Changing counters and drift can be explored with disposable secrets, without enrolling an account.
Keep the protocol boundary visible
The parts list and configuration example make the experiment reproducible. Its nonstandard visual encoding and clock assumptions remain essential parts of that reproduction. Testing with disposable secrets and known counters allows the display, drift hint, and code generation to be evaluated without enrolling a real account.