LoRa tracker

Convoy without coverage: which device you need, how to pair it, what the group sees and how far it reaches.

A convoy normally shares positions over the internet. Where there is no cell signal — a mountain valley, forest, border country — a LoRa tracker takes over: member positions travel by radio, device to device, and land on the same DirtMap map.

Which device

A palm-sized LoRa radio with its own GPS and battery, connected to the phone over Bluetooth. We test with the Seeed SenseCAP Card Tracker T1000-E (card-sized, about $39, several days of runtime) — but any similar LoRa tracker running open mesh firmware works, as long as it exposes the standard Bluetooth service.

One device per car. The trackers talk to each other; the phone only reads its own over Bluetooth.

In Europe they use the licence-free 868 MHz band — no subscription, no SIM, no monthly fee.

First-time setup

  1. Turn the tracker on and put it in pairing mode (on the T1000-E: press the button twice).
  2. In DirtMap: Profile → LoRa tracker → Search for device, then pick it from the list.
  3. Once connected, the menu header shows its name and battery. Use Rename tracker to give it a name people recognise (“Car 2”) — that is the name others see on their map.
  4. Every convoy member does the same with their own unit. Important: the trackers must share one radio channel (factory defaults already do).

One practical detail: on the factory channel positions may travel deliberately blurred (errors of several hundred metres). If you see that, set the channel’s position precision to “precise” in the tracker’s own configuration app, on both devices.

What you see on the trail

  • Members appear in the same list and on the same map as online — marked with an antenna badge to say the position came by radio.
  • Next to it, the age of the last packet (”45s”, “3m”), so you can tell how fresh it is.
  • The menu shows the battery of your tracker and of the convoy’s trackers.
  • All of it works in airplane mode, as long as Bluetooth is on.
  • When cell coverage returns, the app simply uses whichever source is fresher — nothing to switch.

Range

It depends on the terrain, and promising a number would be dishonest:

  • wooded valley, hills in between: a few hundred metres,
  • open ground, a ridge or along water: several kilometres,
  • members in between relay each other’s packets, so the convoy’s chain reaches further than any single hop.

Positions also refresh less often than online: roughly every 15 seconds while moving, once a minute at rest — deliberately, to spare the radio band and the battery. The dot steps rather than glides.

If it does not work

  • The tracker is not found: toggle Bluetooth off and on and put the tracker back into pairing mode; only one app can be connected at a time (close the manufacturer’s configuration app).
  • You cannot see the others: check that both trackers are on the same channel and that both phones run DirtMap in the same convoy.
  • Stuck on “connected” with no data: the app re-reads the radio every 30 seconds and rebuilds the link after three minutes of silence — if it still sits there, disconnect and reconnect from the menu.