M5Stack Fingerprint 2 Unit (A-K323CP)

M5Stack Fingerprint 2 Capacitive Sensor Unit

The M5Stack Fingerprint 2 Unit combines an STM32G031G8U6 controller with an A-K323CP all-in-one fingerprint module. The capacitive sensor handles fingerprint acquisition, feature extraction, enrollment, comparison, storage, and search, providing a compact biometric input for embedded access and identity workflows.

The module stores up to 100 fingerprint entries and communicates through UART at 115200bps, 8N1. A multicolor LED ring provides local status feedback for enrollment, matching, errors, or application-defined states.

Enroll and Match Fingerprints Locally

Fingerprint processing is handled by the module rather than requiring the host to implement the full recognition algorithm. The host can manage enrollment, matching, deletion, and application logic through the serial interface. Define clear administrative procedures for adding and removing templates, especially when devices are deployed in shared environments.

508 dpi Capacitive Sensing

The fingerprint module is specified at 508 dpi with an 80 × 208 image pixel format. The design includes adaptive processing for dry and wet fingers, but real recognition performance still depends on finger placement, sensor cleanliness, skin condition, enrollment quality, and environmental conditions.

Plan Security Beyond the Sensor

A fingerprint match should be only one part of a complete security architecture. Protect template-management commands, define retry and lockout behavior, log administrative changes where appropriate, and provide a secure recovery method. High-value access systems may require additional authentication factors and certified security controls.

Integrate Through UART

UART at 115200bps 8N1 provides a straightforward connection to compatible controllers. Check voltage levels, shared ground, serial routing, startup timing, and command-response handling before enclosure integration. The RGB ring can show state locally without requiring a separate display.

Typical uses include smart locks, attendance terminals, identity verification prototypes, controlled equipment access, and compact security devices. Technical setup details are available in the M5Stack Fingerprint2 documentation.