Rotary Controller Python (RCP)

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 with a dedicated STM32-based control board.

🛒 Purchase all boards from our shop: Provvedo Shop

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🚀 Features

• Responsive touch-capable UI built with Kivy
• Communicates over RS-485 with an STM32 controller for stepper/encoder control (github.com)
• Works on Raspberry Pi 3/4, Windows, macOS, and Linux
• Runs headless on Pi using the custom OSPI OS with pre-installed RCP (github.com)

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🎯 Requirements

• Hardware

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

• Software

  • Python 3.8+
  • uv virtual environment manager
  • kivy, pyserial, and other dependencies from pyproject.toml

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⚙️ Installation & Setup

1. Clone the Repository

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

2. Install uv

Install uv (Linux/macOS):

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

For Windows, follow instructions on the [Astral uv docs].

3. Create & Sync Virtual Environment

uv venv       # creates .venv/
uv sync       # installs required dependencies

4. Run the App

uv run python ./rcp/main.py

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💻 Platform-specific Notes

Windows/macOS/Linux

• Use Python >=3.8
• Virtual environment recommended via uv
• Ensure pyserial can access your RS-485 adapter (permissions on Linux/macOS)

Raspberry Pi & OSPI

• 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*

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🛠️ Troubleshooting

• Serial issues: Verify RS-485 wiring, correct serial port, and permissions
• Service failures (Pi): Check journalctl logs and Kivy log files, check the /var/log folder for OSPI release

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📚 References & Related Projects

• Firmware & hardware: [rotary-controller-f4] (github.com)
• PCB design & BOM: [rotary-controller-pcb] (github.com)
• OSPI OS with pre-installed RCP: [ospi] (github.com)

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🧾 Changelog

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

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🤝 Contributing

Contributions are welcome! Please:

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

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🏆 Support

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

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📄 License

Licensed under MIT. See LICENSE for full terms.

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README last updated: June 23, 2025

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