DroneDot

• Reads the aircraft, not the controller

  Positions come from the flight controller over the MSDK key KeyAircraftLocation3D, so the dot on the map is where the drone is — not where the pilot is standing.

  Satellite count and GPS signal level are surfaced on the status screen so you can tell a weak fix from a lost link.

• Reports to CalTopo Shared Locations

  One unsigned GET per tick to CalTopo’s connect-key position endpoint. The aircraft appears as a live coloured dot on any team map with the Realtime Data overlay enabled, alongside every ground team.

  Click the dot for coordinates and last-update time, or Record to Map to turn the beacon into a saved live track.

• Survives a dimmed screen

  The reporter runs inside a foreground service with an ongoing notification, so dimming the controller or switching back to another app does not stop the beacon.

  Network loss never reaches the GPS listener: the report fails, the count increments, and the next tick carries on.

• No photogrammetry, orthomosaics, contours, DTMs or point clouds
• No camera, gimbal or video access of any kind
• No flight control, waypoints or automated missions
• No altitude, heading or speed — CalTopo does not display them for custom devices
• No queue and no backfill — a SAR map must never show a stale position
• No account, telemetry or analytics — the app talks to CalTopo and nowhere else

Aircraft

DJI Matrice 4TDMatrice 4D Enterprise Series — on the MSDK V5 supported-product list.

Controller

DJI RC Plus 2Android, arm64-v8a only. The RC Plus is the same platform.

SDK

DJI Mobile SDK V5, aircraft package, pinned to 5.18.0MSDK V4 does not support this airframe.

Android

minSdk 24 · targetSdk 35

CalTopo

A Team account with access to Trackable DevicesTeam Admin → Trackable Devices → Create New Access URL.

Install method

Sideload the APKDJI enterprise controllers ship without Google Play Services, so there is no Play Store to install from — the same reason DroneDeploy and Dronelink hand out APKs from their own sites.

1. Step 1

   Sideload the APK

   On a computer with the controller attached over USB and ADB enabled:

   adb install -r DroneTopo-GPS-0.3.0-arm64-v8a.apk

   Or type dronedot.nobrega.com.br/apk straight into the controller’s own browser and install from Downloads. Enable install-from-unknown-sources when prompted.

2. Step 2

   Force-stop DJI Pilot 2 — every time

   DJI Pilot 2 holds the aircraft link. While it is running, a third-party MSDK app will not connect, and the symptom is a silent failure to ever reach READY.

   On the controller: Settings → Apps → DJI Pilot 2 → Force stop. Confirm it is no longer running before launching DroneDot.

3. Step 3

   Create a connect key in CalTopo

   Team Admin → Trackable Devices → Create New Access URL, then copy the generated connect key. A generated key is harder to spoof than one you invent, and the device auto-appears in Trackable Devices on its first report — label and colour it there.

4. Step 4

   Configure DroneDot

   Open Settings and set the connect key, a device ID (for example M4TD-01), the base URL https://caltopo.com, a report interval, and leave Skip invalid fixes on so (0,0) and NaN never reach the map.

   The screen echoes the resulting call sign, {CONNECT_KEY}-{DEVICE_ID}. Check it matches the Trackable Device before you rely on it.

5. Step 5

   Start streaming

   Power the aircraft, wait for the SDK phase line to walk INITIALIZING → REGISTERING → REGISTERED and then READY, and tap Start streaming. A notification reads “Reporting as {call sign}” for as long as the beacon is live.

   On the team map, enable Map Overlays → Realtime Data → Shared Locations. The drone appears as a coloured dot.

# one request per tick — this is the entire CalTopo integration
GET {baseUrl}/api/v1/position/report/{CONNECT_KEY}?id={DEVICE_ID}&lat={LAT}&lng={LNG}

# worked example
GET https://caltopo.com/api/v1/position/report/SARTRUCKS?id=14&lat=36.47375&lng=-118.85302

# on-map call sign, composed by CalTopo — the app only echoes it
SARTRUCKS-M4TD-01

• Latest wins, nothing is queued

  A volatile holder keeps the most recent fix; a ticker sends whatever is in it. On failure the fix is dropped — the next tick sends the current position instead of backfilling a stale one.

  5–10 s is the sane band for a moving aircraft; CalTopo draws straight lines between consecutive reports, so faster reporting means a smoother track. Longer intervals suit loiter, standby or a metered link.

• Locale-safe coordinates

  lat and lng are formatted with Locale.US and %.6f, so the decimal separator is always a dot.

  A comma-decimal controller locale would otherwise emit lat=49,323750 and silently corrupt every report. It is the most common bug class in this kind of integration, and it is covered by a unit test.

• The connect key is a shared secret

  Anyone who learns it can post positions under your call sign. Treat it like a password: it lives only in the app’s Settings screen, and published builds ship with it blank.

  Rotate it in CalTopo if it leaks. DroneDot never implements the signed Team API, so a leaked connect key cannot be used to read or edit your maps.

Version

0.3.0 · released 2026-08-27

File

DroneTopo-GPS-0.3.0-arm64-v8a.apk · 339 MiB Published before the rename, so the 0.3.0 asset filename and its launcher label still read “DroneTopo GPS”. The next release drops the old name.

SHA-256

52009d49b84445f71118a28be1bed93428ebdb0c8e6c3b7661bd25aa824a89e9

ABI

arm64-v8a onlyRC Plus 2 and RC Plus. It will not install on an armeabi-v7a device.

DJI App Key

Bound to br.com.nobrega.m4td.gpsReleased builds carry a working key. Build from source if you want your own key or your own signing identity — the package name must match whatever you register.

Licence

Apache License 2.0

• Releases
• Source & build instructions
• [email protected]