inkplate6flick/advanced/io/io_expanders

# IO Expanders

Control GPIO pins on both internal and external IO expanders on Soldered Inkplate 6 Flick.

## Overview

Demonstrates how to use GPIO pins on both the internal IO expander (IO Expander 1) and the external IO expander (IO Expander 2) on Inkplate 6 Flick. The example alternates blinking an LED connected to the external expander for 5 seconds, then an LED on the internal expander for 5 seconds, repeating continuously.

## Hardware Required

- Soldered Inkplate 6 Flick
- USB cable
- 2× LED + 330 Ω resistor

## Setup

1. Connect one LED + 330 Ω resistor to **P1-7 (GPB7)** on **IO Expander 2** (external).
2. Connect another LED + 330 Ω resistor to **P1-7 (GPB7)** on **IO Expander 1** (internal).
3. Run `idf.py menuconfig` and navigate to:
   **Inkplate Boards → Inkplate6 Flick**

## Build and Flash

```
idf.py build
idf.py -p PORT flash monitor
```

## Expected Output

- External IO expander LED blinks for 5 seconds.
- Internal IO expander LED blinks for 5 seconds.
- Sequence repeats continuously.

## Notes

- **External IO expander (IO Expander 2):** all pins are free to use.
- **Internal IO expander (IO Expander 1):** do **not** use GPA0–GPA7 or GPB0 — these are reserved for display control. Using restricted pins may permanently damage the display. Use only pins GPB1–GPB7 (P1-1 to P1-7).

## Resources

- Docs: https://docs.soldered.com/inkplate
- Support: https://forum.soldered.com/
- Image tool: https://tools.soldered.com/tools/image-converter/