The axiotrax device

A minute on the boat

Easier to show than to describe. This runs from the pre-start countdown into racing, then through a few of the pages you can put on the screen — axiotrax’s own numbers and whatever your NMEA instruments are reporting, side by side.

Nothing on screen is computed on the device. The phone works it all out and pushes finished numbers across, which is why the display never disagrees with the app in your pocket.

Filmed on the boat, not a simulator.

Why this exists

We are a software company, and we are not going to sell you hardware. But the hardest part of a sailing instrument is knowing what to show and when — and axiotrax already does that. What was missing was somewhere to put it that survives a wet cockpit and reads at arm’s length in full sun.

So the device is built from parts you can buy for about the price of dinner, the firmware is free, and the case prints on any hobby printer. You bring the hardware; the app brings the sailing.

Reflective, not backlit The panel makes its picture out of the light already falling on it, so it gets easier to read as the sun gets brighter — the opposite of a phone. It also draws almost nothing to hold an image.
The phone does the thinking Every calculation stays in the app. The device is told where things are and what to draw, never what it means — which is why adding a new number to the app does not need new firmware, and why there is only ever one version of the truth.
One button, no menus Tap to change page. Hold to sleep. It follows your race on its own — counting down before the start, switching to your upwind numbers after the gun — and gets out of the way.
Open firmware, open case The firmware and the enclosure are published. Build one, build five, change the pages, print a different case. Driving one from the app is part of axiotrax Pro; everything else is yours.

What you need

The PCB is most of it, and that includes the display and battery. The rest is a case, a sheet of film and the patience to wait for a print.

Part	Notes	Approx.
Waveshare ESP32-S3-RLCD-4.2	One PCB — the 4.2″ reflective display and the battery are already on it	$40
Printed case — STL files	PETG or ASA. Not PLA — a sunlit cockpit will soften it	filament
Quarter-wave polarizer film	Cut to the panel. Keeps the screen readable through polarised sunglasses. One sheet does 4–10	$7
3M double-sided tape, 1 mm	High-tenacity. Bonds the film and mounts the unit — no fasteners. One roll does 4–10	$7
One unit	Buying everything from scratch	~$55
Each, building ten	The film and tape are already paid for	~$42

The film and the tape are the only things that come in quantity, and one of each covers four to ten units. That makes a fleet cheaper per boat than a single build — a class set of ten is closer to $42 a unit than $55.

The board link is an Amazon affiliate link — if you buy through it we earn a small commission at no extra cost to you. Buy it anywhere you like; nothing about the build depends on where it came from.

Everything above is preliminary and being tested by a handful of people right now. If you are one of them, the things we most want to hear about are battery life over a full day and how the panel reads in glare with polarised sunglasses.

Where to put it

Everyone who sails with one arrives at the same answer within about ten minutes: the mast. It is where your eyes already go, it reads from the rail and from the helm, and it keeps the screen clear of everything else going on in the cockpit.

So we drew the brackets — two sizes covering most one-design and sportboat rigs, plus a mount for anyone already sailing with a Vakaros Atlas 2. All with room behind for the boom lines. They are free to axiotrax sailors.

See the mast brackets →

Want the CAD, not just the STLs

The case files above are ready to print and free to anyone. The source CAD is a different thing: if you want to change the mount, fit it to a different panel, or design a version for your own boat, you need the model rather than the mesh.

We will hand those over, free, to people doing something real with them — builders, coaches, sailing programs, clubs, anyone teaching this. Send us a note saying who you are and what you have in mind. That is the whole application process; we just like knowing where these end up.

Ask for the CAD files →

Install the firmware

Plug the board into this computer with a USB-C cable and press the button. Nothing to download, no toolchain, no command line.

A computer — not a phone or a tablet. Mac, Windows, Linux or Chromebook, all fine. An iPad cannot do this no matter which browser you install on it, because every browser on iPadOS is Safari underneath. Same for Android tablets.
Chrome or Edge on that computer (or another Chromium browser — Brave, Arc, Opera). Flashing needs the Web Serial API, which Safari and Firefox have chosen not to implement. In the wrong browser the Install button below is replaced by a note saying so, rather than sitting there looking ready.
A Waveshare ESP32-S3-RLCD-4.2. The installer checks the chip and will refuse anything that is not an ESP32-S3, but it cannot tell one S3 board from another — flashed to a different S3, this firmware runs and draws nothing you can use.
A USB-C cable that carries data. The single most common reason a board never shows up in the port list is a charge-only cable. If nothing appears, try another cable first.
No driver to install. The S3 talks USB directly, so there is no CH340 or CP210x download — the step every other ESP32 guide starts with does not apply here.

Connect the board to a USB port with a data cable — a charge-only cable will not appear.
Press Install and pick the serial port when the browser asks.
Wait about a minute. The device restarts on its own and shows a four-digit pairing code.
In axiotrax, open Settings → Sailor Profile and add [dev] to the end of your name. The display controls are still behind that switch while this is preliminary.
Go to Settings → Remote Display Dev → Remote Display Link and tap the code you can read on the panel.

If no port appears when you press Install — unplug the board, hold the BOOT button down, plug it back in, then let go. That forces the chip into its download mode, and it will show up. You only need this if the board is unresponsive; a healthy one appears on its own.

Firmware 0.10.5 — for the Waveshare ESP32-S3-RLCD-4.2. A first install erases the board, including anything the vendor shipped and any pairing it already had. Later updates keep it. Nothing here is permanent either way: the board is always one flash away from whatever you want on it.

The beta is open

The screen is half of it.
Get the app.

The display is a window onto what axiotrax is already working out. Install the app, record a race, and it will have something to show.

Join the beta on TestFlight →

Building these with a junior program or a fleet? Email us — we would like to hear how it goes.

A screen for the data you’re already making.