Open framework for closed circuit rebreathers.
Build. Dive. Contribute.
A community-driven hardware and software platform for technical divers, engineers, and developers building safer, more capable rebreather systems.
Rebreathers are life-support equipment. Improper construction, configuration, or use can result in serious injury or death. This project is for educational and research purposes. Never use this project as actual diving equipment. Always use certified commercial equipment for actual diving.
About the Project
What is the openCCR project?
Built by divers and engineers who wanted to see inside the black box.
Why?
Rebreathers are powerful but opaque. Most divers treat them as black boxes — cells vote, solenoids fire, watchdogs run — but few know why or how. That opacity is a problem when the device is your life support. openCCR exists to change that.
- Understand how it really works. Trace every signal from O₂ sensor to solenoid actuation. Read the firmware. Study the schematics. Know your life-support equipment at circuit and software level, not just the operating manual level.
- Debunk the mystery. eCCR design is often treated as arcane knowledge. Open hardware and documented firmware make every design choice visible and reviewable by anyone willing to look.
- Harness the community. Technical divers, engineers, and hackers collectively find more failure modes and generate better ideas than any closed team. openCCR is a venue for those conversations and contributions.
What?
openCCR is not a product and not a certification programme. It is a learning, experimentation and innovation platform and a community reference design.
- A project for tinkering, learning, and having fun. Build a sensor board. Flash the firmware. Break something on purpose and understand why. Modify the PO₂ control loop. Write a new alarm module. Fun and curiosity are the whole point.
- A reference design for the community. A well-documented, open baseline that any builder can fork, extend, critique, or simply read to understand how a serious CCR controller is built — from schematic to protocol specification.
Platform Overview
Everything you need to build a CCR
From schematics to firmware, openCCR covers the full stack of closed circuit rebreather development.
Open schematics, bill of materials, and PCB layouts for sensor boards, controllers, and display modules.
Modular firmware architecture for microcontrollers. Sensor fusion, PO₂ control loops, and dive computer integration.
Drag and drop openCCR boards and components to plan your build. Explore module combinations interactively before ordering.
Documented data protocols, serial interfaces, and extension APIs for building compatible accessories and integrations.
Join engineers and divers. Review open issues, submit pull requests, and discuss design decisions.
Pre-sourced component kits, tested sensor boards, and display assemblies to get your build started faster.
Software-in-the-loop simulation for testing firmware and control algorithms without hardware.
Design Principles
Built for safety-critical systems
Safety First
All designs prioritize fail-safe behavior. Sensor redundancy, hardware watchdogs, and defensive firmware patterns are core requirements, not afterthoughts.
Open by Default
Hardware designs, firmware source code, and documentation are fully open. No proprietary black boxes in life-support systems.
Modular Architecture
Layered hardware and software modules. Swap sensor types, controller boards, or display units without redesigning the entire system.