common (shared NFC helpers)

Shared C++ sources for the dual PN532 ESP-NOW system described in the parent README: protocol definitions, error handling, memory helpers, and other code consumed by listener_firmware/ and emulator_firmware/.

Usage

Firmware sketches include headers via paths such as:

#include "../../common/nfc_protocol.h"

Keep this folder versioned together with:

• listener_firmware/
• emulator_firmware/
• Parent platformio.ini (workspace root)

Splitting into a separate remote is easiest if these three become submodules of a single meta-repo, or you refactor include paths.

Tests

Unit tests that exercise parts of this tree live in tests/.