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.

Already have one? The Device Guide covers the buttons, the pages and running a start from the display.

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 a 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.
Two buttons, plus power ACTION changes the page; hold it to sleep. SEQUENCE pings the start line and starts the countdown. No menus: 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.

Build one

About $55 in parts — the board, which already carries the display and the battery, plus a polycarbonate window, polarizer film, a breathable vent and marine sealant — and a case you print in ASA and TPU. No soldering. A class set of ten comes in nearer $42 a boat, because the film, sheet, vents and sealant go a long way.

The build guide has the full walkthrough on video, every part with a link, and the case files.

See the build guide →

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 →

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. The browser lists only the board — on a Mac it reads USB JTAG/serial debug unit (cu.usbmodem…). Select it and press Connect.
Wait about a minute. The device restarts on its own and shows a QR code.
In axiotrax, open Settings → Remote Display, tap Scan the QR Code and point your phone at the panel.

If the list is empty when you press Install, the computer isn’t seeing the board. Try a different cable first. If that doesn’t fix it, unplug the board, hold the SEQUENCE 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 0.14.0 — 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.