M5Stack Core 3D Printing Mini-Monitor

A small remote monitor for a 3D printer based on an M5Stack Gray (which should be compatible with the newer M5Stack Core models as well). The implementation relies on OctoPrint's HomeAssistant integration to view the downscaled camera image and read the sensor data.

Features

• Live Video Feed: Streams MJPEG snapshots from Home Assistant.
• Split-Screen UI:
  • Top: Status Bar (Bed/Nozzle Temp, Progress Bar, ETA).
  • Middle: Camera Feed.
  • Bottom: Button Labels.
• Multi-Camera Support: Toggle between two different camera entities.
• Flicker-Free Updates: Uses Sprite buffering for smooth UI refreshing.
• Interactivity:
  • Button A: Pause Print (with "Are you sure?" confirmation).
  • Button B: Cancel Print (with "Are you sure?" confirmation).
  • Button C: Switch Camera.

Prerequisites

Hardware

• Implemented and tested on M5Stack Gray (ESP32-D0WDQ6-V3), but would probably work on M5Core models as well.

Software

• arduino-cli or Arduino IDE.
• Home Assistant instance with OctoPrint integration configured.

Home Assistant Configuration

Crucial Step: The M5Stack Gray has limited RAM. You must create a downscaled proxy camera in Home Assistant, or the device will crash trying to decode full HD images.

Add this to your Home Assistant configuration.yaml:

camera:
  - platform: proxy
    entity_id: camera.octoprint_camera # Your actual high-res source camera
    name: "Octoprint Camera Downscaled"
    max_image_width: 320
    max_stream_width: 320
    image_quality: 75

Restart Home Assistant after adding this.

Installation & Flashing

This project uses a self-contained sketch.yaml to manage board cores and library dependencies.

1. Clone and Configure

1. Clone this repository.
2. Copy the example config:

   cp config.example.h config.h

3. Open config.h and enter your:
   • WiFi Credentials.
   • Home Assistant URL (e.g., http://192.168.1.100:8123).
   • Home Assistant Long-Lived Access Token (Create this in HA User Profile -> Security).
   • Entity IDs for your cameras and OctoPrint sensors.

2. Compile and Upload (Using Arduino CLI)

This project includes a sketch.yaml that defines the exact M5Stack platform and libraries required.

1. Initialize the Core & Libraries: Run this command in the project directory. It downloads the M5Stack core and required libraries (M5Stack, TJpg_Decoder, ArduinoJson) automatically based on sketch.yaml.

   arduino-cli core install
   arduino-cli lib install

2. Compile:

   arduino-cli compile .

3. Upload: Connect your M5Stack via USB and identify the port (e.g., /dev/ttyUSB0 or COM3).

   arduino-cli upload -p /dev/ttyUSB0

Usage

• Boot: The device will connect to WiFi, fetch the initial sensor data, and start streaming.
• Button A (Left): Request to PAUSE the print. Shows a confirmation screen.
• Button B (Center): Request to CANCEL the print. Shows a confirmation screen.
• Button C (Right): Toggle between Camera 1 and Camera 2.
• Status Bar:
  • B: Bed Temperature.
  • N: Nozzle Temperature.
  • ETA: Estimated time remaining (Calculated from HA timestamp).
  • Idle/Heating/Printing: Status text updates based on printer state.

Troubleshooting

• Screen flashes white/black: Check the Serial Monitor. If you see Image too large, ensure you are using the Downscaled camera entity in config.h.
• HTTP Fail 404: Check your Entity IDs in config.h.
• HTTP Fail 401: Check your Long-Lived Access Token.
• Upload Fails: Ensure your USB cable supports data (not just power) and that no other software (like Cura or Arduino IDE) is hogging the serial port.