Reverse engineering the Anycubic Photon Mono 4K

This documents the reversing of the Mono 4K, which helps in writing the open-source firmware Turbo Resin.

Table of content

• Part 1: Discovery of the hardware and firmware extraction
• Part 2: Planning the read of the external flash
• Part 3: Creating a Rust development environment
• Part 4: Dumping content of the external flash
• Part 5: Graphics extraction from the external ROM
• Part 6: Taking control of the user-facing LCD display
• Part 7: Detecting touches on the display and improving on the original firmware
• Part 8: Driving the Z-axis stepper motor
• Part 9: Driving the LCD Panel, and displaying a print layer from the USB stick
• Part 10: Elegoo Saturn: display images from USB to the LCD panel

Introduction

The Anycubic Mono 4K is my first 3D printer. It's been quite a steep learning curve to print with resin, but it's really satisfying to make objects once the workflow is ironed out.

Here's the printer.

Here's an example of a printed object.

~~There are visible lines due to the lack of anti-aliasing support on the printer. Its LCD screen outputs only fully transparent, or fully opaque pixels, no gray-scale. Apparently, we have to wait for a firmware update, but I'd rather not wait.~~

Update: The original firmware handles anti-aliasing just fine.

Reverse engineering the printer will guide our implementation of a new firmware, Turbo Resin, so we can add the features that we want.

Resources

• Datasheets: datasheet folder
• Original firmware: firmware folder
• UI images: /firmware/ui folder
• PCB photos: pcb folder
• Pin config: print_ports_config.py and port_config.txt
• Turbo Resin firmware: (https://github.com/nviennot/turbo-resin)
• Our discord channel: https://discord.gg/9HSMNYxPAM