Brushograph PCB

This repository contains the KiCad PCB design files for the Brushograph (miniPenzlograf) project, a pen-plotting device designed for creating artistic drawings and patterns.

A manufacturing-ready PCB-design to run FluidNC on ESP32 including ULN2003 drivers for 3 uni-polar stepper motors (28byj-48)

A DIY etchable PCB-design to run FluidNC on ESP32 including ULN2003 drivers for 3 uni-polar stepper motors (28byj-48)

About Brushograph

This PCB repository is part of the larger Brushograph project, which explores "Ways of painting with a mechatronic brush" - an intersection between classical artistic techniques and modern technology.

Main Documentation:

• Brushograph Wiki - Complete project documentation

Project Structure

• Brusograf_PCB/ - Main KiCad project directory
  • .kicad_pcb files - PCB layout files
  • .kicad_sch - Schematic files
  • .kicad_pro - Project files
  • MASK/ - Contains mask files in SVG and PDF format for PCB silkscreen
• Brushograf_PCB-china/ - Latest KiCad project prepared for fabrication
  • Gerber_Brusograf/ - Generated Gerber set for PCB manufacturing
  • Gerber_Brusograf_black.zip - Zipped Gerbers ready to upload to your PCB manufacturer
• FluidNC_config/ - Configuration for FluidNC firmware
• photos/ - Project photos and documentation images

Features

• Custom PCB design for the Brushograph device
• ESP32-based control board with FluidNC firmware support
• Integrated ULN2003 drivers for 3 uni-polar stepper motors (28byj-48)
• DIY etchable single-layer design for easy home fabrication
• Rounded PCB version available
• Configuration files for FluidNC firmware (custom fork for support uni-polar steppers)

Hardware Configuration

ESP32 Pin Configuration

The Brushograph PCB uses the following ESP32 GPIO pins for controlling the stepper motors via ULN2003 drivers:

X-Axis Motor (Unipolar)

• Phase 0: GPIO 27
• Phase 1: GPIO 14
• Phase 2: GPIO 13
• Phase 3: GPIO 4

Y-Axis Motor (Unipolar)

• Phase 0: GPIO 16
• Phase 1: GPIO 17
• Phase 2: GPIO 21
• Phase 3: GPIO 22

Z-Axis Motor (Unipolar)

• Phase 0: GPIO 26
• Phase 1: GPIO 25
• Phase 2: GPIO 33
• Phase 3: GPIO 32

SD Card (SPI)

• MISO: GPIO 19
• MOSI: GPIO 23
• SCK: GPIO 18
• CS: GPIO 5

Motor Configuration

The config.yaml file in the FluidNC_config directory contains all necessary settings for the stepper motors:

• X/Y Axis: 85 steps/mm, 1000mm/min max rate, 50mm/s² acceleration
• Z Axis: 78 steps/mm, 1000mm/min max rate, 30mm/s² acceleration

28BYJ-48 Stepper Motors

The PCB is designed specifically for the commonly available and inexpensive 28BYJ-48 unipolar stepper motors:

• 5V DC operation
• Gear reduction ratio of 1:64
• Step angle of 5.625° (64 steps per revolution)
• 4-phase operation via ULN2003 driver

Getting Started

To view or modify the PCB design:

1. Install KiCad (version 6.0 or later recommended)
2. Open the .kicad_pro project file in the Brusograf_PCB directory
   • For the latest manufacturing-ready version, you can also open the project in Brushograf_PCB-china/

For complete setup instructions, including firmware and mechanical assembly, please refer to the Brushograph Wiki.

Manufacturing-ready files

• Latest Gerbers (ZIP, ready for fab): Brushograf_PCB-china/Gerber_Brusograf_black.zip
• Gerber folder (all layers and drill files): Brushograf_PCB-china/Gerber_Brusograf/

Related Repositories

• FluidNC for unipolar steppers - Forked and reworked version of FluidNC to support uni-polar steppers

License

[Specify license here]

Credits

Designed by dusjagr

The Brushograph project is based on Dominik Mahnič's "Brušografia" concept, bridging traditional painting and technology.

Contact

[Your contact information here]