A Kivy-based Digital Read-Out (DRO) and single-axis controller UI for rotary tables and similar devices, designed to run on Raspberry Pi or desktop environments (Windows, macOS, Linux). Interfaces via RS-485/Modbus RTU with a dedicated STM32-based control board.

🛒 Purchase all boards from our shop: Provvedo Shop

• Responsive touch-capable UI built with Kivy
• Communicates over RS-485 Modbus RTU with an STM32 controller (rotary-controller-f4)
• Configurable axes — add/remove axes, assign hardware scale inputs, apply transforms (identity, scaling, weighted sum, angle cos/sin)
• Electronic Lead Screw (ELS) mode for synchronized threading and power feed on manual lathes
• Sync mode with configurable gear ratios for spindle-synchronized movement
• Circle pattern calculator for bolt hole patterns
• Customizable display: fonts, colors, digit formats (metric/imperial/angle)
• Contextual help — info button on every setting field with documentation and examples
• Works on Raspberry Pi 3/4/5, Windows, macOS, and Linux
• Runs headless on Pi using the custom OSPI OS with pre-installed RCP (ospi)

• Hardware

  • Rotary controller board (STM32 firmware from rotary-controller-f4)
  • RS-485 interface (e.g. via Power Hat)
  • Raspberry Pi 3/4/5 for Pi deployments

• Software

  • Python 3.10+
  • uv package manager

git clone https://github.com/bartei/rotary-controller-python.git
cd rotary-controller-python

Install uv (Linux/macOS):

curl -LsSf https://astral.sh/uv/install.sh | sh

For Windows, see the uv installation docs.

uv sync

uv run python -m rcp.main

uv run pytest

• Python >= 3.10
• Virtual environment managed automatically by uv
• Ensure your RS-485 adapter is accessible (check serial port permissions on Linux/macOS)

• Install an SD card image from the OSPI project

• RCP is pre-installed in /root/rotary-controller-python/

• To update:

  sudo systemctl stop rotary-controller
  cd /root/rotary-controller-python
  git pull
  uv sync
  reboot

• View logs:

  journalctl -u rotary-controller
  journalctl -xeu rotary-controller
  tail -n +1 /var/log/kivy*

rcp/
├── main.py                    # Entry point (asyncio + Kivy event loop)
├── app.py                     # MainApp class
├── feeds.py                   # Feed/thread pitch configurations
├── help/                      # Contextual help documents (markdown)
├── components/                # UI layer
│   ├── home/                  # Home screen (coordbar, servobar, elsbar, statusbar)
│   ├── screens/               # Full-screen views (setup, scale, servo, formats, etc.)
│   ├── widgets/               # Reusable form widgets with help button support
│   ├── popups/                # Modal dialogs (keypad, help, feeds table, etc.)
│   ├── toolbars/              # Toolbar buttons
│   └── plot/                  # Plot/visualization
├── dispatchers/               # Event dispatchers and state management
│   ├── saving_dispatcher.py   # Auto-persisting properties to YAML
│   ├── formats.py             # Display format settings
│   ├── circle_pattern.py      # Circle pattern calculator
│   └── board.py               # Board/device event dispatcher
└── utils/                     # Hardware communication layer
    ├── communication.py       # ConnectionManager (Modbus RTU)
    ├── base_device.py         # C typedef parser and register I/O
    └── devices.py             # Device type definitions

• Serial issues: Verify RS-485 wiring, correct serial port, and permissions
• Service failures (Pi): Check journalctl logs and Kivy log files under /var/log/
• Display issues: Adjust font size and display format in the Formats setup screen

• Firmware & hardware: rotary-controller-f4
• PCB design & BOM: rotary-controller-pcb
• OSPI OS with pre-installed RCP: ospi

See CHANGELOG.md for detailed history, updates, and breaking changes.

Contributions are welcome! Please:

• Open issues for bugs or feature requests
• Submit pull requests or improvements
• Help with testing, documentation, porting new features

Join our Discord community for support, collaboration, and updates.

Licensed under MIT. See LICENSE for full terms.