xl9555_input

# XL9555 Input Example

This example reads a single XL9555 input 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
- Input pin: P0

If your wiring differs, use `idf.py menuconfig` -> "XL9555 Input 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 Input Example".
- Configure driver defaults via `idf.py menuconfig` -> "ESP IO Expander XL9555".
- XL9555 does not provide internal pull-ups/pull-downs; ensure external circuitry sets a defined input level.