08-11-2026 
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Ask any group of BSV users what wallet infrastructure they need most, and a hardware signing device for cold storage comes up quickly. It’s something the community has wanted for years, but without a good solution. Trezor is openly hostile to BSV. Ledger and KeepKey don’t support it, but used to work through ElectrumSV (though grudgingly and indirectly).
- PiWalletSV: A hardware signing device built for BSV
- Web pioneer revives hardware wallets
- From wallet woes to hardware innovation
- Cold storage without compromise
- A wallet anyone can assemble
- Small project, big ambitions
Now there’s a new and promising-looking option, and it comes from the place that often delivers what everyone really wants: one developer, a 3D printer, and a Raspberry Pi.
PiWalletSV is an open-source, air-gapped, hardware signing device for BSV, built from a Raspberry Pi Zero W, a small display bonnet, and a camera. The device that holds the keys has no Wi-Fi, Bluetooth, or Ethernet. A companion web app on a phone or laptop talks to the blockchain; the Pi only signs. Data crosses the air gap as animated QR codes, in and out, through the camera and screen.
The project launched just last week with little fanfare, offering an initial run of ten kits with custom 3D-printed cases at $129. They all sold out within days.
A builder with pedigree
The developer is Monte Ohrt, and his name may be familiar to anyone who built websites in the 2000s. Ohrt created Smarty, the template engine that underpinned a generation of PHP applications, starting the project in 1999 and spending about 15 years as a PHP developer before moving into MySQL administration and, these days, cloud architecture.
His Bitcoin history goes back almost as far as Bitcoin itself. In May 2011, a colleague asked if he knew about it.
“That was when I first heard of it. I pulled up the website, read the whitepaper and I was completely floored,” Ohrt told CoinGeek. “This is different to Liberty Dollar, CyberCash, anything else that claims to be digital money.”
He and his business partner bought GPUs and started mining, pulling in around 2 BTC a day at one point. The Butterfly Labs scandal later cost them about half their stash. As the years and forks went by, he moved his coins from BTC to BCH and finally to BSV.
“I kept rolling it into what I saw as the real Bitcoin,” he said. He now describes BSV as “a 2011-level opportunity,” and points to Teranode and scaling progress as signs that “there’s a moment coming.”
Project born from frustration
PiWalletSV exists because every other option failed him. Ohrt managed his cold storage with ElectrumSV and a Ledger Nano until the Ledger hardware degraded and lost compatibility. He switched to a KeepKey, which worked with ElectrumSV but only indirectly.
“Those wallets are always BSV-hostile, the people who manage and code them,” he said. “I didn’t like using it with hardware that was BSV hostile.”
Then ElectrumSV went dark. ElectrumX servers started going offline, sometimes breaking things on the way out. When the community-forked ElectrumSVP arrived, it dropped hardware wallet support entirely. That was the final motivation. Ohrt researched how to build a cold wallet from available open hardware, chose the Raspberry Pi stack, and wrote the software himself, with the project taking about three months.
“Hostility, closed source software, they break things. Creating things for BSV has always had to be a bit of a hack,” he said. “But no longer.”How PiWalletSV works
The companion app, a watch-only wallet that runs in any modern browser, sees only the public key. It discovers coins, builds an unsigned transaction, and packages it with SPV proofs as an animated QR code. The Pi scans it with its camera, re-verifies every input’s Merkle proof against block headers on the device itself, shows the transaction details on its own screen, and signs only when the user presses a button. The signed transaction travels back to the companion the same way, by QR, for broadcast.
Ohrt is open about where the design sits on the security spectrum.
“I would say the PiWallet has mostly SPV support, but not the full loop,” he said, noting that, as an air-gapped device, it cannot talk to the network itself and must rely on headers supplied by the companion. Even so, re-verifying proofs on the signing device goes beyond mainstream hardware wallets, which trust the vendor’s backend view of the chain.
The core promise is simpler. “No one can steal your keys when they’re on an airgapped device,” Ohrt said.
The seed phrase is generated on the Pi at setup and written down on paper by the user; it is never stored on the device at all. What the PIN-protected vault encrypts is the master private key derived from that phrase, which does the actual signing. Lose or break the Pi, and the same keys can be regenerated from the paper phrase using any standard BSV wallet tool. Users can add entropy at setup with a camera photo or even by rolling dice and typing in the results. The device should still be treated like the seed phrase itself: kept somewhere safe, brought out only when coins need to move.
He is equally open about what isn’t finished yet. The six-digit PIN will be lengthened in an upcoming firmware release to resist offline cracking. He also noticed that the device’s screen does not yet show the destination address for comparison with the companion app, and is fixing it.
“There’s only about five devices out there so far,” he said, but emphasized that there will always be upgrades and that upgrading is user-friendly.
DIY by design
The kit is the easy path, but not the intended one. Ohrt would rather people build their own: the parts are all off-the-shelf consumer components costing roughly $60 to $85, the case files are free to 3D-print, and the software is a signed image flashed to an SD card. Could a non-developer manage it?
“Yes absolutely, if you can follow the basic instructions to assemble it, if you can 3D-print the case,” he said.
The outer case itself gets some engineer’s pride. Ohrt insisted on screws rather than snap-fit joints.
“This is over-engineered. That’s me. If you know me, you know how solid it is. It’s not going to fall apart.”
Everything about the project is open. The wallet software is on GitHub, and the QR wire protocol is a documented open spec, so anyone can build a compatible signer or companion app. Even ElectrumSVP could add support for it if its developers choose to.
Ohrt also built the project’s entire online store himself: a fully automated e-commerce backend that takes credit cards or BSV, calculates shipping, tracks orders, and sends confirmations. The whole backend was assembled in about three weeks (with the help of agentic tooling). For those interested in other forms of key protection, his other side project Keyslice generates Bitcoin keys and formats them into printable “slices” for distribution to separate physical locations.
A side project, for now
Ohrt makes no grand claims about the future.
“At the moment it’s just a personal side project,” he said. “If thousands of people suddenly want one, it would be worth pursuing as a business. But for now, it’s just a guy in his basement with a 3D printer and a bunch of Pi boards.”
He’s unsure if that kind of demand is coming, though, and says so plainly.
“I mean, it only supports BSV. It could support any coin you want, in theory, but I built it to store BSV,” said Ohrt.
Raspberry Pi supply shortages, driven by artificial intelligence (AI) and data center demand, also limit how fast kits can scale, though he wants to support newer Pi models when boards become more obtainable.
For a community that has waited years for a hardware wallet that doesn’t treat BSV as an enemy, though, the significance is larger than the first batch size. The software is open, the hardware is ordinary, the keys never touch a network, and the first ten kits are already gone. It’s a start, and a solid one.
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