mmc_front_display/CLAUDE.md

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.