Device setup
There are two parts, both handled here in the browser: flashing the firmware onto the head unit over USB, and building offline map tiles for its SD card. Everything runs locally on your computer — no data is uploaded.
01 — Flash firmware
This writes the firmware to the head unit directly from the browser over a USB cable, using the Web Serial API — no separate installer or command line. It runs entirely on your computer; nothing is uploaded.
Plug it into your computer with a USB-C cable. Put it in flashing mode:
hold BOOT, tap RESET, then
let go of BOOT. Click Connect and pick the
usbmodem / USB Serial port that appears.
Pick a version from the dropdown. The newest is already selected, so you can usually leave it as-is.
The latest release is selected by default.
Click Flash firmware and wait for it to finish — it takes about a minute. When it’s done, tap RESET on the head unit and it boots into the new firmware.
02 — Generate an offline map
Pick an area and the browser bakes the very same H3 map tiles the companion app builds — one .ebm per hexagon under /maps/tiles on the SD card. Everything runs locally from OpenStreetMap data (via Overpass); nothing is uploaded. (The app additionally bakes in elevation; that’s the one thing the browser leaves out.)
Pan and zoom to where you ride, then Draw a box (drag across the map) or Use current view. Keep it modest — a city or a county is fine; a whole state is too much data for one download.
Pan and zoom to your area, then draw a box or use the current view.
Click Generate map — it fetches the roads for your area and bakes the
.ebm right here in your browser.
Download the tiles, then unzip onto the SD card’s root and they land in
/maps/tiles automatically — over the built-in USB-drive mode, or with
a card reader. They show up on the map screen the next time you ride through that area.