xl9555_basic

# XL9555 Basic Example

This example toggles the configured XL9555 pin (default P0) every 500 ms using the ESP-IDF `i2c_master` driver.

## Hardware Setup
- Board reference: ATK-DNESP32S3-BOX
- I2C port: 0
- SDA: GPIO48
- SCL: GPIO45
- XL9555 I2C address: 0x20
- Toggle pin: P0

If your wiring differs, use `idf.py menuconfig` -> "XL9555 Basic Example" to adjust.

## Build and Flash
```bash
idf.py set-target esp32s3
idf.py build flash monitor
```

## Notes
- The example uses the local component via `EXTRA_COMPONENT_DIRS` in `CMakeLists.txt`.
- Configure example pins/address via `idf.py menuconfig` -> "XL9555 Basic Example".
- Configure driver defaults via `idf.py menuconfig` -> "ESP IO Expander XL9555".