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Open Hardware for Open Money
Bitcoin is a monetary network built on hardware components. Specialized chips, hashboards, control boards, and signing devices determine who can participate in mining, run infrastructure, and hold keys offline. Closed and proprietary hardware concentrates power in manufacturers and large operators, working against Bitcoin's decentralized design. Open-source hardware and firmware shift power to individuals and local communities by providing them with designs they can audit, adapt, and run on their own terms.
Over the past year, OpenSats has provided targeted support to builders who create Bitcoin hardware as free and open-source infrastructure. Their projects live in public repositories, with schematics, firmware, manufacturing files, and documentation available for anyone to inspect and reuse. Many of these builders design for constrained environments, giving users more options to run their own miners and signers.
Following earlier impact reports on Lightning infrastructure, developer libraries, education, wallets, and ecash, this report focuses on Bitcoin's hardware layer and the developers building open tools for mining and self-custody. The five projects highlighted here make home mining accessible using transparent designs, enable local partners to manufacture and repair boards, deliver affordable DIY air-gapped signers, and assemble an open mining stack for independent operators.
These projects are:
Having mining hardware and signing devices as public infrastructure lowers barriers to entry and expands the pool of people who can meaningfully participate in Bitcoin. Let's take a closer look at how each of these open-source projects has made an impact over the past year.
Bitaxe
Bitaxe is an open-source bitcoin mining project, led by hardware designer skot, that gives individuals and small operators a practical way to contribute directly to network security. With support from OpenSats, the project's focus has been on closing the gap between open design files and hardware that people can build, run, and understand. Each release moved that goal forward by making manufacturable boards with matching firmware available to anyone willing to assemble them.
The BitaxeGamma line marked a major step in mining decentralization by using the BM1370 mining chip that reaches roughly 1.2 terahashes per second on a compact board intended for home or small deployments. The team published the BitaxeGamma 600/601/602 hardware releases, with the full set of manufacturing materials, including schematics, printed circuit board (PCB) layouts, bills of materials, and assembly data. Hardware producers can now build Gamma units directly based on the public design files. On the firmware side, the ESP-Miner 2.6.1 release brought stable support for Gamma, adding self tests, temperature handling, tuning controls, and an improved web interface. A new Gamma is able to power up, check its own state, connect over Wi-Fi, and join a mining pool from a browser on the local network using only open-source software.
In January 2026, this progress extended into a higher performance tier with the Bitaxe GT 801 platform. GT 801 combines two BM1370 chips on a single board and uses an open-source heatsink design that enables sustained operation at higher power levels. The project published the first GT 801 hardware release, complete with circuit files, mechanical drawings, and parts lists, which makes it possible for manufacturers and builders with circuit board experience to produce GT units directly from the repository. Soon after, the ESP-Miner 2.12.2 firmware release added full GT support, with its own self-tests and power-management logic, and is available as a ready-to-install firmware download. Community vendors (like Solosatoshi) now offer GT 801 miners that deliver around 2.15 terahashes per second at roughly 43 watts, which gives small operators an efficient, open design that runs on standard household power and fits in compact spaces.
In parallel with these hardware advancements, the team improved AxeOS Swarm, a dedicated UI to manage multiple Bitaxe units that can function as a mining fleet. ESP-Miner 2.11.0 and its beta releases introduced a grid view in the browser interface, layout refinements, clear color coding for different device types, and device notifications. Operators can see metrics such as hashrate, temperature, and pool status for Max, Ultra, Supra, Gamma, and GT boards on a single screen to identify which miners require attention. API improvements and an OpenAPI description make it easier to automate fleet management, including coordinated firmware updates and the collection of long-term statistics across multiple devices.
Across each hardware and firmware release during this period, the project built a growing base of independent miners who control their own hardware and software. Those miners now run Bitaxe units from homes, workshops, and community spaces, contributing hashrate to the network on their own terms.
My best estimates put the number of Bitaxe units sold to date at over 100,000. Self-sovereign, private miners have solo mined at least six blocks. The project has achieved incredible momentum while being steadfast in its commitment to privacy, open source, and decentralization. Thanks to the generous financial support from OpenSats I can still focus on adhering to these project goals. It would never be possible with a for-profit company running the show.
—skot, Bitaxe project lead
Bitaxe's progress illustrates how open miner designs can scale in practice and anchor meaningful hashrate in hardware that miners themselves can inspect, modify, and operate.
Bitshoka
Bitshoka, maintained by Kuenrg153, extends the work from Bitaxe into local manufacturing in Kenya and open research on MicroBT ASICs. For miners across Africa, even entry-level hardware like the Bitaxe Gamma remains out of reach when shipping costs, import rules, and currency constraints are taken into account. OpenSats funding gave the team the resources to pursue that directly, building Bitaxe-compatible hardware locally and publishing boards that give developers direct access to Whatsminer chips.
Bitshoka V1.0 started from the proven BitaxeGamma 600 design and adapted it into a locally branded miner for the Kenyan and wider African bitcoin community. The hardware is a complete copy of the Gamma board, based on the BM1370 ASIC, with artwork that reflects its African origin. The repository includes KiCad projects, schematics, layout files, and manufacturing outputs, so local partners can produce boards directly based on the files in the repo. Bitshoka boards are now running successfully, validating the local manufacuring process and confirming that these Made in Africa miners behave like their BitaxeGamma counterparts while using the same ESP-Miner firmware and configuration flow.
Bitshoka Nini V1.1 focuses on MicroBT's Whatsminer ASICs and the KF1950 chip used in the M30 series. The Nini repository publishes a full KiCad design for a Bitaxe-style board built around the KF1950, including detailed circuit diagrams, PCB layout, mechanical drawings, a list of materials, and manufacturing files. The project reports that the first batch of boards has been assembled and that a PicoBT controller can detect and read the KF1950 on the board. Testing revealed a noise issue on the power rail that prevented mining, and the team has since designed a revised V1.2 board to address it.
To make ASIC research and experimentation more accessible, the bitLode project adds a dedicated bridge between a standard computer and Whatsminer hashboards. bitLode is a fork of the earlier aditBoard design, which reshapes it into a board that adapts the data cable from Btmicro and Whatsminer M30 hashboards to USB. The repository contains its own KiCad project, documentation, and manufacturing files, along with tagged hardware revisions that mark specific layouts ready for PCB orders. Once built, bitLode lets developers connect a laptop directly to production hashboards, capture and replay traffic, and study how the KF1950 responds under different conditions. In combination with Bitshoka Nini, Bitaxe Raw, and logic analyzers, this gives engineers a practical path from raw signal traces to documented protocols and, eventually, open firmware that can drive MicroBT-based miners.
Being a part of the Kenyan bitcoin community, we can see how even an entry-level miner like the Bitaxe Gamma is both logistically and financially inaccessible to most people here. As well as adding MicroBT [Whatsminer] ASICs to the Bitaxe ecosystem, the Bitshoka Nini will provide an avenue for miners from emerging markets to get their hands on their own hardware to start learning, experimenting, and developing.
—Kuenrg153, Bitshoka project maintainer
OpenSats funding has helped the project focus on publishing designs, documenting findings, and keeping the work open-source for community reuse. The result is a manufacturing path for builders in Kenya and a growing set of open tools for developers studying MicroBT chips anywhere in the world.
Krux
Krux is a firmware project that turns inexpensive, off-the-shelf circuit boards into air-gapped bitcoin signing devices. In places like Brazil, taxes and import fees often double the price of electronics, putting commercial hardware wallets beyond the reach of many people. OpenSats funding supported two core contributors, Odudex and Tadeubas, who worked to make self-custody practical on affordable, widely available hardware.
Under Odudex's lead, the 25.03.0 release added support for Taproot and P2WSH wallets that follow Miniscript. Krux can now load a wallet descriptor that defines who can spend, under which conditions, and when. The device displays it in a structured way and checks that the cosigners and rules match the user settings before a transaction is approved. SD-card signing reliability was improved, so when a transaction file (PSBT) moves from one signer to another on an SD card, Krux is able to keep the information intact, including signatures already added on other devices, so that multi-signature setups can pass around one file and see signatures accumulate. In the same release, the camera gained a zoom option and improved performance under glare, making QR code based signing easier. Interface updates also enhanced keypad layouts and introduced a simpler tamper-check screen optimized for small displays.
A second set of changes from Odudex focused on how Krux protects and stores sensitive data. The Krux Encryption Format (KEF), introduced in the 25.09.0 release, gives users a way to encrypt seeds and other secrets with protection against brute force attempts, and the possibility to move those encrypted envelopes using QR or SD card while staying offline. Contributor Jean Do led the design of KEF as a secure envelope format for air-gapped devices, while Odudex helped implement the low-level parts into Krux. On top of KEF, the new Datum tool lets users turn plain text into encrypted records. Users can write instructions, recovery hints, or account notes and save them in KEF format as QR codes or SD card files, so important context sits next to wallet backups in a human-readable yet protected form.
Performance and long-term architecture were also a focus for Odudex. He reduced the size of the Krux firmware by 25% and enabled hardware acceleration for encryption and hashing on supported boards. Users gained quicker QR handling, faster transaction signing, and better responsiveness on low-cost devices. To support this, he wrote cUR, a pure C library for handling UR-based QR codes, and is integrating it into Krux as a MicroPython module. cUR makes reading and writing multi-part QR codes much faster than the older Python-only approach, which matters when a backup or transaction spans many QR frames.
Odudex has also been building Kern, a C implementation of a Krux-style signer for the ESP32-P4 chip. Kern already runs on several boards, can scan static and animated QR codes, load keys, and sign transactions, and aims to deliver reliable air-gapped signers for under fifty dollars on widely available hardware.
By building Kern on widely available, future-proof, low-cost hardware without sacrificing performance or usability, we can bring reliable Bitcoin self-custody to people who were previously priced out of quality signing devices. The tools I created along the way, like cUR, are open for anyone to use, and hopefully can benefit other projects.
—Odudex, Krux contributor
Working alongside Odudex, Tadeubas concentrated on safety checks, address handling, security hardening, and device support in the main Krux firmware. He identified and fixed a vulnerability that allowed firmware to be compromised through the SD card, and later implemented anti-rollback protection after Craig Watkins raised the issue during the review process to list Krux on Bitcoin.org. His work on the Embit library and Krux itself improved how the signer understands complex wallet definitions. Krux is now able to recognize more edge cases and gives a clear warning when it cannot confidently determine which addresses are meant for change. That warning appears before signing, which lowers the chance that funds end up at an unexpected address because of a subtle wallet configuration issue. This kind of prevention is especially valuable for communities and services that use condition-based wallets to protect shared funds.
Tadeubas also redesigned how Krux displays and exports addresses, with readability in mind. Receive addresses now appear in short, consistent groups with clear labels and highlighting, so users can compare what they see on Krux with what a coordinator or application shows on-screen without scanning a dense block of characters. A new export wallet addresses to SD feature writes a full list of receive addresses to a file for offline review or for use in external tools. This helps when setting up donation pages, payout flows, or services that need a list of addresses generated from an offline signer.
On the hardware side, Tadeubas used grant funds to bring Krux to the TZT touchscreen device, which combines a milled aluminum case with both touch input and physical buttons. Porting Krux to TZT required changes in the underlying MaixPy firmware for display, buttons, and camera support, and this work shipped as new device support in the v25.10.0 release. TZT gives users a more rugged and comfortable form factor, which many users prefer for long-term key storage. Beyond this, Tadeubas is also developing the Krux Apps (Kapps) framework, including a nostr-focused app that would let Krux act as an offline nostr signer in future versions.
Projects like Krux don't just add another tool; they strengthen the entire Bitcoin self-custody ecosystem by promoting openness, affordability, air-gapped security, and resistance to centralized control or suppression. Contributing to that effort, with OpenSats' support, has been deeply rewarding.
—Tadeubas, Krux contributor
Krux runs on widely available K210 boards and now on devices like TZT, Yahboom, Maix Cube, WonderMV, and Embed Fire, so more users have a practical path to running their own air-gapped signer on hardware they can afford. OpenSats funding helped both contributors dedicate time to these changes and keep the roadmap focused on open-source development.
Krux-Installer
Krux-Installer is the desktop application that allows users to install and update Krux firmware on supported devices. Getting firmware onto a signing device has traditionally required command-line tools and technical knowledge that many users don't have, which puts a practical barrier between people and the hardware they want to use. OpenSats funding gave developer qlrd the time to rewrite the installer into a stable, cross-platform tool that guides users through safe downloads, verification, and installation without requiring specific technical knowledge.
Over the past year, Krux-Installer transitioned from an earlier JavaScript and Electron prototype to a new Python and Kivy codebase and reached its first stable release with v0.0.20. The application guides users to select their device model, choose a Krux firmware version, download it from the official source, and let the installer check that the file is authentic and unchanged. The same binary runs on Windows, macOS, on Intel or Apple chips, and common Linux distributions such as Debian-based systems and Fedora, so people can follow the same steps regardless of their desktop setup. For many users, this has become the recommended way to get Krux onto a device without having to learn command-line tools.
A major focus for qlrd was creating a firmware update path for people who prefer to keep their signing devices completely offline. Starting with v0.0.20-beta, Krux-Installer introduced an air-gapped update flow that prepares an SD card with the correct firmware files and a matching signature, then shows a fingerprint of the firmware on screen. The user can insert that SD card into a Krux device, walk through the on-device update, and compare the fingerprint shown on the computer with the one displayed on the signer's screen. If the two fingerprints match, the user can be confident that the update is genuine and unchanged, and the device was offline the entire time.
The 0.0.20 release also bundled a set of safety and access improvements. Users gained a one-click wipe device option for supported devices, which completely removes the existing Krux firmware, so a signer can be decommissioned or returned to a clean state without manual recovery steps. The interface now supports twelve languages and runs on a broad set of Krux devices, including M5StickV, Maix Amigo, Sipeed Bit, Sipeed Dock, Maix Cube, Yahboom, and WonderMV. The 0.0.21 release extended this work to include Nix packaging and added support for installation on newer devices, such as the TZT and Embed Fire, keeping the installer aligned with the growing Krux hardware ecosystem.
Krux-Installer now runs on Windows, macOS, and common Linux distributions, supports twelve languages, and covers a broad set of Krux devices, making it practical also for non-English speakers and non-Linux users to manage their own signers. OpenSats funding provided qlrd the time to complete the rewrite, so that as new devices get supported, users have a simpler way to install firmware on them.
256 Foundation
The 256 Foundation focuses on building an open, end-to-end mining system that anyone can study, modify, and run. Bitcoin mining infrastructure today is largely built on closed hardware running proprietary firmware, which concentrates a critical part of the network among a small number of manufacturers. OpenSats funding supported the team's effort to change that by advancing the Ember One open hashboard and the Hydra Pool mining software into production-ready tools that individual miners and small groups can operate themselves.
Ember One/00 v3 delivers a fully documented hashboard design centered on Bitmain's BM1362 ASICs and designed to draw around 100 watts from a wide 12-24 volt power input. In practical terms, Ember One gives builders a standard board that holds the mining chips, handles power delivery, and connects over USB to a separate control board, using standard interfaces that are easier to inspect and replace. The KiCad project, manufacturing files, and assembly guide for the v3 release are public, and the design has already been validated on real hardware. That combination allows a small manufacturer, a workshop, or an educator to start from a proven layout, order boards, and assemble working miners while understanding each step of the design.
Hydra Pool advanced into a deployable mining pool server that aligns with the same open approach. It is implemented in Rust and supports both solo mining and a PPLNS (Pay Per Last N Shares) pool mode for reward distribution, where participants share rewards over time based on their recent work. Payouts go directly into the first transaction in each block, which creates the mining reward, so the pool software never takes custody of user funds. Hydra Pool also exposes an API for miners to download their own share records and includes dashboards built on common monitoring tools for tracking hashrate and uptime. Recent releases package this into binaries and container images that run on standard Linux servers and connect to a Bitcoin full node, which makes it realistic for a club, business, or regional community to operate its own pool with verifiable accounting.
At the first Telehash fundraiser in January 2025, the 256 Foundation solo mined bitcoin block 881,423 live during the event using a self-hosted FutureBit Apollo node, raising 3.146 BTC in rewards that the team used to bootstrap Hydra Pool. In January 2026, the 256 Foundation brought these components together again during another Telehash fundraiser event. Using a pick and place machine on site, the team assembled Ember One hashboards and Libre Board control boards, flashed them with their own Mujina mining firmware, and pointed the hashrate to a Hydra Pool instance that they operate. The result was a live demonstration of an open mining system from the hashboard, to the control board, to firmware, to the pool, running in front of donors and viewers. The foundation demonstrated that all four projects in its mining suite now function together as a complete system for miners and operators, and remain available as individual codebases and schematics for builders and researchers.
The 256 Foundation has taken the first steps with proven success in open-sourcing the entire Bitcoin mining stack: hash board, control board, firmware, and pool. Although the nominal hashrate and power consumption are small compared to industrial-sized closed-source miners, this is a significant achievement in establishing an open-source foundation that can support an alternative path forward for the entire Bitcoin mining ecosystem, one that avoids the perils of centralized control, closed firmware, and proprietary hardware. Bitcoin miners of all shapes and sizes can start benefiting from open-source, standardized, and fully customizable software and hardware today.
—Econoalchemist, 256 Foundation co-founder
The 256 Foundation has advanced this work from early prototypes to live demonstrations and production-ready releases, while keeping each layer documented and available for the wider community. The result is a more geographically diverse and resilient foundation for mining infrastructure that independent operators can study, run, and build on themselves.
Each project in this report operates on the same principle: publish the designs, document the process, and make the work available to anyone. Taken together, they show how open hardware can reach meaningful scale, cross geographic and economic barriers, and cover every layer of the mining and self-custody stack.
This work strengthens Bitcoin in ways that complement its open-source software. Hardware that can be studied, reproduced, and repaired spreads knowledge into new communities and reduces dependence on traditional supply chains. Miners, educators, and small manufacturers now have reference designs they can fork, adapt, and use to teach others.
OpenSats remains committed to funding builders who keep Bitcoin's hardware infrastructure open, auditable, and accessible. To support projects like these and others, please consider making a recurring donation to the General Fund.
If you are a developer, hardware designer, or researcher working on free and open-source projects that strengthen Bitcoin, we encourage you to apply for funding.