M5StickC-Plus Image Display System

Table of Contents

• Project Overview
• System Architecture
• Directory Structure
• Technical Specifications
• Features
• Installation
• Development Notes
• Contributing
• License
• Authors

Project Overview

This project implements a web image display system using an M5StickC-Plus device with a supporting Python server for image processing. The system fetches images from a web source, processes them to the correct display dimensions, and shows them on the M5StickC-Plus LCD screen with proper error handling and user feedback.

System Architecture

Components

1. M5StickC-Plus Client

   • Handles image display and user interface
   • Manages WiFi connectivity
   • Implements memory-efficient image downloading
   • Provides visual feedback with loading bar and status messages

2. Python Image Processing Server

   • Pre-processes images to exact display dimensions (240x135)
   • Serves scaled images via HTTP
   • Implements automatic image refresh
   • Handles image download and scaling operations

Directory Structure

/
├── esp32_client/
│   ├── main.py           # Main M5StickC-Plus program
│   └── boot.py           # Boot configuration
│
└── server/
    ├── image_server.py   # Image processing server
    ├── config/
    │   └── config.json   # Server configuration
    ├── images/           # Image storage
    ├── logs/            # Server logs
    └── venv/            # Python virtual environment

Technical Specifications

M5StickC-Plus Client

• Display: 135x240 LCD (ST7789v2 driver)
• Memory: ~47KB available RAM
• Operating Mode: Landscape (rotation 1)
• Screen Brightness: 25%
• Image Format: JPEG (240x135 pixels)

Server Requirements

• Python 3.x
• PIL (Python Imaging Library)
• HTTP Server
• JSON Configuration
• Logging System

Features

Client Features

• WiFi connectivity with error handling
• Efficient image downloading with chunked transfer
• Progress bar for download status
• Memory management with garbage collection
• Auto-refresh every 60 seconds
• Manual refresh via Button A
• Status message display
• Error recovery mechanisms

Server Features

• Image scaling to exact display dimensions
• Automatic image refresh
• RESTful image serving
• Configuration management
• Logging system
• Service management

Installation

Server Setup

1. Set up Python environment and install dependencies:

python -m venv server/venv
source server/venv/bin/activate
pip install pillow requests jsonschema

2. Configure the server:
   • Edit server/config/config.json with appropriate settings
   • Set up the service:

sudo cp image_server.service /etc/systemd/system/
sudo systemctl enable image_server
sudo systemctl start image_server

Client Setup

1. Flash MicroPython to M5StickC-Plus
2. Upload main.py to the device
3. Configure WiFi settings in main.py:

SSID = 'your_wifi_ssid'
PASS = 'your_wifi_password'
URL = 'http://your_server_ip:8080/image.jpg'

Development Notes

Memory Management

• Chunk-based downloads (512B chunks)
• Regular garbage collection
• Memory monitoring
• File cleanup routines

Display Optimization

• Pre-scaled images from server
• Centered status messages
• Thin loading bar (4px)
• Black background for text visibility

Error Handling

• Network connectivity recovery
• Memory allocation failures
• File system management
• Download timeouts

Contributing

Contributions are welcome! Please follow these steps:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Push to the branch
5. Create a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Authors

For questions or support, please open an issue in the repository.