# CLAUDE.md

## Project Summary

This project uses an ESP32-S2 and a 240x240 round GC9A01 TFT display to indicate which of two systems is currently active.

At startup, a logo is displayed for approximately 10 seconds. After the startup period, the display shows either "SYSTEM A" or "SYSTEM B" based on the state of a GPIO input.

## Development Goals

* Keep firmware simple and maintainable.
* Minimize memory usage.
* Avoid unnecessary dependencies.
* Ensure fast boot and reliable operation.
* Use Arduino IDE compatibility.

## Hardware

### MCU

ESP32-S2

### Display

* GC9A01
* 240x240 pixels
* SPI interface

### Input

Single GPIO input used to determine:

* HIGH = System A
* LOW = System B

## Preferred Libraries

### Display

* TFT_eSPI

### Image Support

* TFT_eSPI sprite functions
* PROGMEM image storage

## Display Behaviour

### Startup

* Initialize display.
* Show startup logo.
* Hold logo for approximately 10 seconds.

### Normal Operation

Display one of:

SYSTEM A

or

SYSTEM B

The display should update immediately if the input state changes.

## Coding Standards

* Use clear descriptive variable names.
* Avoid dynamic memory allocation.
* Store constant strings in flash where practical.
* Keep functions small and focused.
* Comment hardware-specific sections.

## File Structure

src/
├── main.ino
├── display.cpp
├── display.h
├── logo.h
└── config.h

## Expected Features

### Required

* Display initialization
* Startup logo
* GPIO monitoring
* System A/B status display

### Optional

* Screen dimming
* Custom fonts
* Status icons
* Animated transitions

## Notes

This is an embedded appliance-style device intended for continuous operation in a rack-mounted environment. Reliability and simplicity take priority over additional features.