# common (shared NFC helpers)

Shared C++ sources for the **dual PN532 ESP-NOW** system described in the [parent README](../README.md): 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:

```cpp
#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/`](../tests/).