Libre Board
Open-source hardware Bitcoin miner control board
Libre Board is an open-source hardware control board for Bitcoin miners, designed to run Mujina firmware and Linux-based tools. It enables hardware hackers to build custom mining setups — from standard pool mining to hashrate heating and solar-powered mining.
Why This Is a Core Grant
A miner control board is the brain of any Bitcoin mining operation, handling the connection between the hash board, power supply, network, and user interface. All existing control boards are proprietary black boxes. Libre Board provides an open, hackable alternative that enables an entirely new class of mining applications.
Why It's Necessary
Open control board hardware is the bridge between open firmware (Mujina) and open hash board hardware (Ember One). Without it, even an open firmware runs on a closed hardware stack. Libre Board completes the open-source mining stack, enabling use cases like hashrate heating integration, solar mining controllers, Home Assistant integration, and fully custom mining appliances.
Build What You Need — Strip What You Don't
Libre Board is a reference design, not a prescribed product. It is intentionally comprehensive — every interface it exposes is something a real mining system builder might need. You take the full design, remove what does not apply to your use case, compact the form factor if you want, and build from there. The richness is the point: it teaches you everything a control board can do, so you can make informed choices about what yours should do.
Building for an industrial data center
You probably don't need a display, GPIO sensors, or a Bitcoin node on your control board. Strip those components, tighten the form factor, finalize your BOM, and manufacture at scale. Libre Board gives you a fully documented open starting point so you're not reverse-engineering a proprietary black box to get there.
Building a hashrate heating system
A pool heater that happens to mine Bitcoin is a system — not just a miner. You may want to wire temperature sensors, water flow meters, and pump controls directly to the control board. Libre Board's GPIO pins and Linux environment make the miner the brain of the entire heating system, not just one component in it.
Building an off-grid or solar mining system
Managing variable DC input from solar panels or batteries requires custom logic and real-time sensor data. Libre Board's compute versatility, NVME storage, and open Linux environment give you the foundation to build and run that logic directly on the control board — no separate controller needed.
It's a Linux computer, not just a control board
Because Libre Board runs full Linux, the hash board is just one of the things it can talk to. It can simultaneously run a Bitcoin full node, serve as a local Stratum server, display a system dashboard, run Home Assistant, or manage any custom application you write. What you build on top of it is up to you.
Technical Details
Libre Board is an SBC-form-factor control board running full Linux, licensed under CERN-OHL-S. It accepts 12–24V DC input and exposes a comprehensive I/O set: USB hub, Ethernet, HDMI, NVME, WiFi, MIPI (touchscreen), RPi 40-pin header, fan connectors, and two 100-pin compute module connectors. The dual 100-pin CM design supports swappable compute modules across architectures including Raspberry Pi CM5, RISC-V, and ARM — making it adaptable as compute technology evolves. Out of the box it runs Mujina firmware, but its full Linux environment also supports Bitcoin full node operation, a Stratum server, Home Assistant, and any custom Linux application.
Key Specifications
Features & Compatibility
I/O Interfaces
- →USB hub
- →Ethernet
- →WiFi
- →HDMI
- →NVME expansion
- →MIPI (touchscreen)
- →RPi 40-pin header
- →Fan connectors
- →2× 100-pin compute module connectors
Compute Compatibility
- →Raspberry Pi CM5
- →RISC-V modules
- →ARM modules
- →Swappable architecture design
Capabilities
- →Mujina firmware (native)
- →Bitcoin full node
- →Stratum server
- →Home Assistant integration
- →Custom Linux applications
switch C21 and C52 to 50V, 0805 size and reposition; Rev2 text
Michael Schmid · 8mo ago
switch places of C52/C54 and C21/C22 - in order for easier compatbility with Rev2
Michael Schmid · 8mo ago
Rev1
Michael Schmid · 8mo ago
Update thickness of traces, smaller fixes
Michael Schmid · 9mo ago
Update README and replace images: removed outdated edge views and top face view, added new
Michael Schmid · 9mo ago
updating traces: min 1.3mm width, diff pairs lengths
Michael Schmid · 10mo ago
Schnitzel
@Schnitzel
Lead Engineer
Open-source infrastructure builder and Bitcoin home miner. Founder of Nakamoto Heating and Amazee.io, Schnitzel brings deep systems engineering experience and a passion for sovereign Bitcoin mining to the Libre Board project.
Econoalchemist
@econoalchemist
Project Manager
Bitcoin educator, technical writer, and co-host of the POD256 podcast. Co-founder of the 256 Foundation and project manager across all four pillar grants.