An incomplete driver for the HZ Grow R502 fingerprint reader module

Uses embedded-hal and arrayvec. It's not intended to be a complete implementation of the R502 command set but rather enough for a simple fingerprint verification device.

Feature support

• Authenticating with the device and querying status
• Searching the fingerprint library
• Verifying selected fingerprints
• Enrolling and deleting fingerprints

For more, see the projects.

Examples

Some examples are meant to be run on a full PC rather than an embedded device. Use a serial to USB converter at 3.3V power and logic levels. I recommend the ESP-PROG.

Contributing guidelines

If you want to send a PR, please make sure that your changes work on a real R502 (if your changes modify anything in the driver itself). For issues, do a cursory check to see if a similar issue has already been filed.

Please follow Rust's code of conduct.