Systems
A complete offline-first operating suite — eighteen field tools for navigation, mesh comms, and stamped records that never phone home. Run it on your own Raspberry Pi 5 or x86 Ubuntu machine, or on a GREYFATHOM terminal built to take the field. No carrier. No subscription. No infrastructure to fail.
Field tools under one fullscreen console. Navigation, mesh, records, control.
Cloud services to depend on. Everything runs on the device, offline by design.
Ways to run it — your own Pi 5, or a rugged terminal we build and test.
Real screenshots below. The night frames are pixel-audited: green and blue at zero.
The suite
Step outside a cell footprint and most software turns into a glass brick — the map won't load, the notes won't sync, the assistant has nothing to say. GREYFATHOM starts from the opposite assumption: no signal, no server, no second chances. Eighteen tools, one fullscreen console, everything on the device — whether you run it on your own Raspberry Pi 5 or on a terminal we build for the field.
100%
Offline-first
Maps, comms, logs, and AI all run locally. Nothing needs an internet connection to work.
18
Field tools
Navigation, mesh radio, record-keeping, and system control under one launcher.
1
Install command
One self-contained package, one script. Flashes onto a Pi 5 and boots to a purpose-built console.
Every tool is installed and enabled on every unit. What a tool can do depends on the hardware fitted to that unit — a radio, a receiver, an antenna. Nothing is held back by a licence.
Meshtastic mesh messaging over LoRa. Text and broadcast across a self-healing radio network — every node relays for the others.
needs LoRa radioFull Meshtastic node control for the Heltec V4 — region, channels, power, every module — from the terminal itself. Detailed below.
needs LoRa radioA command node and common operating picture — track positions and share situational awareness across a team on the mesh.
Spectrum monitoring with a supported SDR dongle — scan and observe the RF environment around you.
needs SDR dongleA real language model on the unit itself — llama.cpp with Qwen 3, plus Ollama and any .gguf you drop in from USB. No account, no cloud.
Unit maintenance and provisioning — the operator controls for keeping a terminal serviced and mission-ready.
A live GPS dashboard — fix quality, satellites in view, coordinates in your format, and heading. Straight from the unit's receiver.
needs GPS receiverAn offline tile viewer. Pre-load the terrain you care about and pan, zoom, and locate yourself with zero connectivity.
A structured field log. Every entry time- and position-stamped on the spot, then exported to USB or the unit's storage.
Fast, stamped notes for when there's no time to format anything. Capture it, move on — saved with when and where.
A real fullscreen shell with a built-in terminal emulator — no desktop needed. Drop to the command line whenever.
A file manager for moving exports, maps, and documents on and off the unit and USB media.
A full Chromium browser for when you do have a link — a LAN dashboard, a captured hotspot, a base-camp network.
The full manuals, guides, and references — quick start, apps guide, troubleshooting, field care — on the device, offline.
Battery state, live current draw, and power profiles — see exactly how long you have and tune for endurance or performance.
System status and a built-in self-test — confirm the unit and its attached hardware are reporting green before you head out.
The same factory soak test we ship against — compiles the suite, verifies fitted hardware, then stresses CPU, memory, and disk. PASS / FAIL, with a report.
Wi-Fi and Bluetooth in one place — join a base network, tether a phone, or bring up the unit's own hotspot.
The unit serves a web app to your phone — logbook, position, mesh, radio, self-test, manuals, and a line to the on-device AI. Pair with a 6-digit code, LAN only.
Display and power preferences, in-place tier unlocks with a signed key, and the unit's identity — serial, tier, version — at a glance.
New · GREYFATHOM OS v1.3
Nine gated releases, one direction: the interface got its identity, and the field work got sharper. Everything below is in the build at code cutoff.
v1.3.0-rc1 is at code cutoff, in production testing. The screenshots in this guide were captured on v1.2 — new captures of the chamfer-cut interface land as testing wraps, and every one will be a real frame, same as today.
Seen live, not rendered
Every frame below is a real screenshot of GREYFATHOM OS v1.2 on the shipping build — captured during the same automated pass that QA-validates each release. No mock-ups, no renders of a screen. Power on, and this is where you land. These frames show v1.2; the v1.3 chamfer-cut refresh is in production testing, and new captures land with it.
Captured on Xvfb at 1280×800 from the live GUI, seeded with a SAR shift. Prefer to poke it yourself? Every tool is one tap from the console — and the whole page flips to the unit's night-vision red with the ☾ in the top bar.
Night-vision red
One tap on the ☾ in the top bar and this whole page flips — because on the unit, so does every app. Night mode is a red chosen for what the human eye physically does in the dark. Try it, then see the real thing below.
Night vision lives in your rod cells — and rods are nearly blind to deep red while wide open to green and blue. The instant a screen shows any green or blue, it starts burning down the dark adaptation you spent an hour building, and on a ridgeline it announces exactly where you are.
GREYFATHOM's night mode is pure red channel — green and blue held at zero. Contrast comes from brightness, not colour. It isn't a dimmed white screen and it isn't a tint bolted over the map; it's the real thing, and it flips every app at once — Maps, Comms, SDR, the console — not just one.
One tap takes the whole terminal dark-safe on your way out. Rather not think about it? Add the ambient light sensor and it crosses to red on its own as the light drops, and back at dawn.
Straight answer
Red night mode isn't ours to claim — plenty of devices have one. What's ours is the discipline: pure red channel, every app and not just the map, tuned so the screen stays readable at arm's length while your eyes stay adapted. On the hardware panel, that's the difference between a checkbox and coming home able to see.
Manual is standard. Automatic is the upgrade. The one-tap switch ships on every unit; the ambient light sensor that flips it for you is an add-on option, fitted at build or by return.
The exact palette the software ships (_PALETTE_NIGHT in gf_ui.py) — green and blue read zero on every value, pixel-audited at each release. Judge the colour on the unit's own panel, not a desktop monitor.
New in the suite
The Meshtastic phone apps are great — until your phone is dead or absent. Radio Config puts the entire node configuration on the terminal itself, built and tested against the Heltec WiFi LoRa 32 V4. Every setting the device and the phone apps expose — over USB, or over Bluetooth LE so a paired radio can sit on a mast while you configure it from your hand.
Second screen
The terminal serves a web app to any phone on its hotspot or LAN. No app store, no account, no cloud — pair once with a 6-digit code shown on the unit, and your phone becomes a second screen even while the terminal is mounted on a mast, packed in a bag, or two rooms away. Try the live demo — enter the code and explore.
Comes with every unit. The server runs as a boot service — your phone connects before a single window is opened. Phone Link is just the switch and the pairing code.
Interactive demo · pairing code 3F9A21BC · simulated telemetry
Two ways to run it
The exact same software, either way. Load it onto hardware you already own, or get a GREYFATHOM terminal with it installed and tuned on purpose-built, field-ready hardware. Turn it on and go.
Option A · Software
Download the full installation package and put it on your own Raspberry Pi 5. Ideal if you already build and maintain your own field hardware.
Delivered as a single install package
See software pricingOption B · Device
The software you just read about, pre-installed and tuned on rugged, field-built hardware — from a pocketable node to a base-station terminal. Radio, GPS, and power fitted and tested.
Configured to your mission
Configure a terminal01 · The line
Three rungs, one standard. A node that lives in a jacket. A gasketed Linux handheld built for the field. And a terminal in a Pelican case that runs the map, the mesh, and the mission. Everything here talks to everything else.
Rung 01 · Join the mesh
GFT-1C COMPACT and GFT-1E NODE. No screen, no compute — just a radio, a cell, and a gasketed shell. Every one you add extends the network for everyone else on it.
From $89 ENCLOSURE KIT
Rung 02 · Carry the compute
GFT-5 MINI. A Raspberry Pi 5 and a mesh radio inside a carbon-nylon chassis drawn around the electronics from the first millimetre. Position, mesh, and Linux in one hand.
From $199 KIT · $749 ASSEMBLED
Rung 03 · Run the mission
GFT-7 and GFT-X. A real keyboard, a real screen, and the full GREYFATHOM OS suite — maps, TAK, SDR, and an assistant that never phones home.
From $889 GFT-7 ASSEMBLED
Flagship · Pi 5 handheld
Gasketed Linux handheld with an onboard mesh radio.
$749 vented
$899 gasketed · $199 enclosure kit
Endurance mesh node
The one you hand to someone who's out all day.
$199 assembled
$99 enclosure kit
Carry mesh node
Because a node you leave at home protects nobody.
$179 assembled
$89 enclosure kit
Carry terminal
Opens flat on a tailgate. Closes into a Pelican Vault V100.
$889 assembled
One price, every tool enabled — fitted modules decide what each tool can do.
Command terminal
A real desk that closes into a Pelican 1500.
$1,339 assembled
One price, every tool enabled — fitted modules decide what each tool can do.
In development
A keyboard handheld, and a way to issue twenty nodes at once.
Soon first article / architecture
Specifications not verified
| Model | Role | Compute | Radio | Display | Size & mass | From |
|---|---|---|---|---|---|---|
| GFT-1C | Compact node | Heltec WiFi LoRa 32 | SX1262 · SMA | — | 62 × 110 × 16 mm · 37 g shell | $89 |
| GFT-1E | Endurance node | Heltec WiFi LoRa 32 | SX1262 · SMA | — | 74 × 120 × 16 mm · 46 g shell | $99 |
| GFT-5 | Mini terminal | Raspberry Pi 5 | SX1262 · Heltec V4 | 5″ | 145 × 114 × 46 mm · 147 g shell | $199 |
| GFT-7 | Field terminal | Raspberry Pi 5 · 16 GB | LoRa · fitted option | 7″ | Pelican Vault V100 | $889 |
| GFT-X | Base station | Raspberry Pi 5 · 16 GB | LoRa · fitted option | 13.3″ | Pelican 1500 | $1,339 |
How the line fits together. Nodes carry the mesh. Handhelds and terminals ride on it and give you a screen, a shell, and a map. Buy the terminal you'll work at, then hand a node to everyone who needs to be on it — that's the whole architecture, and it's why the cheapest thing here is the one that makes everything else worth more.
02 · GFT-5 MINI
Most "rugged" handhelds are a consumer board wrapped in rubber. The GFT-5 is a gasketed carbon-nylon chassis designed around the electronics from the first millimetre — every standoff, rail, and gasket groove cut from one parametric model.
Inside: a Raspberry Pi 5 running your full Linux stack, a Heltec V4 riding its own bay with nylon clamp posts so nothing shorts a GPIO pad, and an L76K GNSS feeding position straight into the mesh.
The 16 mm button would have looked absurd on this wall — 44% of the side. We measured, sized down to 12 mm, and re-cut the nut relief when the mesh probe found the nut colliding with a chamfer. That is the level this thing is built to.
The Pi 5's SoC sits face-down against the rear shell. Bolt on the machined 6061-T6 cold-plate and heat leaves through a short, direct path — no fans, no vents, nothing to clog.
Not ready for the cold-plate? Print the honeycomb rear instead. Pointy-top cells, 5 mm across flats, 43% open area, and enough wall left to bond an ePTFE membrane behind it — air moves, water doesn't.
Swap between them without touching a single internal component. The mounting geometry is identical because both come from the same generator.
03 · GFT-1E NODE · GFT-1C COMPACT
LoRa doesn't need towers. Every node you add extends the network for everyone else on it. Hand these to a team and they stay in contact across terrain that eats cell coverage alive.
Both units share the same sealed construction: a complete TPU seal family — face-frame gasket, display gasket, button pad, tethered USB-C plug, pogo cap. Nothing is an afterthought, because nothing was added after the fact.
These two shells are byte-frozen against a verified baseline. Every time we change anything else in the line, they're re-checked to prove they didn't move.
04 · GFT-7 & GFT-X
A keyboard, a screen you can read at arm's length, and the full GREYFATHOM OS suite. Same operating system, same tier ladder, same discipline — one is sized to carry, the other is sized to work on.
Pelican Vault V100 · weather-resistant
The carry unit. Opens flat on a tailgate, a hood, or your knees. Small enough to keep with you, complete enough to work from.
Pelican 1500 · IP67 when closed
The working unit. A 13.3″ screen and a full keyboard with an integrated trackball — a real desk that closes into a case.
How to choose. Capability is identical — you are choosing a screen and a keyboard, not a feature set. Take the GFT-7 if the unit travels on your back and gets opened on uneven surfaces. Take the GFT-X if you will sit at it for an hour, read a map at arm's length, or hand it to someone else to read. One more difference worth weighing: the GFT-X's Pelican 1500 is IP67-rated closed (Pelican's figure, case unmodified); the GFT-7's Vault V100 is weather-resistant, not waterproof — so if the unit will meet real water, the GFT-X is the one.
The front of a GF terminal is a single printed plate: honeycomb venting, framed windows, an engraved data plate, and the trident. The same cell geometry as the GFT-5 rear, at a different scale. Below, the base plates in silver.
The same plate with nothing bright on it. Engraving in matte graphite instead of bronze, silver, or gold — legible up close, quiet at a distance. Available on any tier; the tier is recorded on the data plate rather than in the finish.
Identical geometry, identical engraving. Only the finish changes. Base plate is finished to match.
Chosen when a unit shouldn't catch light or attention. It is a finish, not a capability.
Blackout changes how the unit looks, and nothing else. It does not alter emissions, sealing, or what the radios do. A blackout Command terminal transmits exactly as loudly as a gold one.
05 · One standard
The full software is on the card the day it arrives, with every tool enabled from the first boot. There are no tiers, no unlock keys and no licence upgrade path. What a tool can do depends on what hardware is fitted — and that is the only thing that costs more, because it is a physical part.
Every tool in the suite is in the image already. There is no licence server to expire, no account to deactivate and no key to lose. A terminal that works on the bench works the same on the tenth year of a dead network.
$99 · one licence, everything in it
Charging to reveal a tool would have meant building a lock, maintaining the lock, and explaining the lock.
Comms needs a LoRa radio on the board. Position and Maps need a GNSS receiver. The spectrum tools need a receiver on the USB port. Fit the part and the tool comes alive; leave it off and the tool tells you what it is waiting for.
Fitted modules, not licence bits
One master image per architecture. The launcher probes for hardware at start and builds the menu from what it finds.
09 · Choose your loadout
No signal, and a decision to make anyway. Pick the one closest to yours and we'll name the terminal, the tier, and the nodes that put your team on the same mesh.
Search & rescue
—
10 · Why it survives
Every claim below is measured off the actual geometry that produces your part. Not a render. Not a marketing round-up.
01
Every shell is proven one connected, manifold body on disk before it ships — no holes, no stray edges. Geometry that passes a visual check can still fail on the plate, so we verify it rather than trust the eye.
02
Audited in print orientation: the faceplate has 57 mm² of roofs, all at bed level. The carry slot and honeycomb have none at all. No scars, no cleanup.
03
Dimensions come off a caliper or they don't go in the model. That rule exists because inferred numbers cost us print cycles once. They don't anymore.
04
The Heltec clamp posts take nylon M2 screws only. Steel there risks shorting a GPIO pad. Small detail — the kind that decides whether a device comes home working.
05
The top slot loops a 12 mm strap over a 4.5 mm full-height carbon-nylon beam, printed so the layer lines run across the load, not along it.
06
Five M2.5 screws and the faceplate is off. Brass heat-set inserts, not self-tappers into plastic. Rebuild it on a tailgate.
11 · Pricing
Two ways to get it. The software suite installs on a Raspberry Pi 5 you already own. Or take a terminal: a mechanical kit for people who source their own electronics, or fully assembled, flashed, and tested — built to order by tier. Every path uses the same signed tier keys; unlock in place, no re-flash.
| Product | Kit | Price | Availability |
|---|---|---|---|
| GREYFATHOM OS suite · your Pi 5 | — | $99 | Download |
| GFT-1C COMPACT | $89 | $179 | Shipping |
| GFT-1E ENDURANCE | $99 | $199 | Shipping |
| GFT-5 MINI — vented rear | $199 | $749 | Shipping |
| GFT-5 MINI — sealed cold-plate | — | $899 | Cold-plate pending |
| GFT-7 FIELD TERMINAL | — | $889 | Built to order |
| GFT-X BASE STATION | — | $1,339 | Built to order |
| Auto day/night — ambient light sensor | — | Contact | Upgrade option |
| GFT-K — keyboard terminal | — | TBA | First article |
| GFV-20 FLEET VAULT | — | Contact | Fleet enquiry |
The software suite is the same image either way — buy it once for your own Pi 5 ($99, a one-time licence with free v1.x updates), or get it pre-installed and tuned on a terminal. The signed tier keys are the same whether it's your Pi or ours. Assembled units arrive flashed and tested; kits include every printed part, the TPU seal family, and the fastener set. The LoRa radio is fitted to every unit at build, whatever the tier; the $99 Command unlock is the signed key that activates it — applied in place, no return, no re-flash. A touch panel can be added to any tier at order.
12 · Next
Two products in the shop right now. We'd rather tell you where they are than pretend they're done.
First article printed
Keyboard field terminal.
Prototype in hand. Power architecture and keyboard selection outstanding. Its CAD lives in a separate project and its specifications are not verified here.
In architecture
Twenty-bay charge & dock cradle.
For organisations issuing nodes at scale. Talk to us before you plan a fleet around it.
13 · Alternatives
You already own something that does part of this. Here is where each of them stops, in our own words, without pretending they're bad tools.
Does better
More compute, a real GPU, software you already licensed. Cheaper if you own one.
Stops when
The hotspot has no bars. The hinge takes a knee. The battery is sealed and it's hour nine. Most of your tools assumed a connection and quietly stopped working.
GREYFATHOM
Assumes no connection from the first boot, and swaps its own cells.
Does better
Lighter, cheaper, one hand, an app store, a camera. Genuinely good at maps.
Stops when
You need a keyboard, a shell, a spectrum display, or an SDR dongle on a USB port. Accounts, sign-ins, and background sync are assumed. Storage is soldered in.
GREYFATHOM
Is a computer with a shell prompt, real USB ports, and a card you can pull.
Does better
Global coverage, SOS, pocket-sized, weeks of battery. Nothing here replaces one.
Stops when
You need to read a map, hold a picture, run a log, or say more than a short message. It is a link, not a workspace, and it costs a subscription.
GREYFATHOM
Is the workspace. Carry the messenger too — we'd fit Iridium beside it, not instead of it.
14 · In the field
0312 · Ridge, no bars
Two teams are working sectors that overlap on paper and not on the ground. The GFT-X sits open on the tailgate with the mesh up, and every member is carrying a NODE. Each check-in lands as a marker. When the second team clears a draw, the picture updates for everyone who can hear a node — which is everyone, because nobody is asking a tower for permission.
GFT-X Command · 4 × GFT-1E NODE
0640 · Line brief, smoke layer
The forecast came off the truck radio and the map came off the card. Nobody has a signal and nobody needs one. The GFT-7 opens flat on a warm hood, the assignment goes into the logbook stamped and legible, and the divisions get walked on a map that doesn't stall waiting to load a tile it never cached.
GFT-7 Command · 3 × GFT-1E NODE
1450 · Transect, day eleven
Eleven days of counts, positions, and photographs. No cloud sync to fail, no account to expire, no upload quietly retrying against a dead antenna. At the end of it, a card comes out of the terminal and goes into a reader, and the record is exactly as complete as it was in the field.
GFT-X · GFT-5 MINI
Plain terms
These are serious tools, and we'd rather you trust the spec sheet than be impressed by it. Here is what a GREYFATHOM is not.
Who builds this
GREYFATHOM Systems is a small shop in Iowa City — one workbench, one person, one standard. Every unit is drawn, printed, assembled, flashed, and tested by hand. Nothing here is pulled from a catalogue, drop-shipped, or finished by a line that never sees the field it's built for.
It started at that workbench, building a cyberdeck with my son. That build turned into something else — the idea that the tools people carry past the edge of coverage should be built to the same standard as the work they do out there. GREYFATHOM was founded in 2026 in Iowa City to build exactly that.
It's not a cold start. It runs from growing up on a farm in north-central Iowa through college, the U.S. Armed Forces, fintech development, custom-engineered rugged tech for defense prime contractors, to systems administration at a world-class healthcare research institution. That's the background, aimed at one problem.
It shows in the parts you'll never see on a spec sheet. Every shell comes from a single parametric model, so nothing is a one-off. Dimensions come off a caliper or they don't make it into the design. Every part is proven a single, manifold body before a printer ever runs. It's slower — and it's why a GREYFATHOM comes home working.
I build in small batches on purpose — it keeps me close enough to the bench to answer for every unit that leaves it.
Built by hand in Iowa City, USA. Sold in small runs, direct.
GREYFATHOM
SYSTEMS
The name
A fathom is the sailor's depth measure — six feet, the span of two outstretched arms, sounded by hand with a lead line. It's the oldest self-reliant way of knowing where you stand: you measured it yourself, and nothing had to transmit it to you. Grey is the condition you do it in — overcast, smoke, dusk; the hours between full coverage and none.
That's the whole name: take your own soundings when nothing outside will tell you where you stand. The trident is the hand tool of the deep — three tines, the way the suite has three tiers — set in a shield: a capable thing inside a protective shell, the way a Pi rides in a Pelican. It's a design mark, not insignia. The stencil wordmark, the engraved-through plates, the all-red night palette — everything here is marked to be handled, not displayed.
Built in small batches in Iowa City. Printed, assembled, flashed, and tested by the person who designed them.