# DJI MSDK Sample (Flutter)

A sample app demonstrating how to drive the **DJI Mobile SDK V4** from **Flutter**.

DJI does not ship an official Flutter SDK — the Mobile SDK is a native
Android/iOS library. This project therefore puts a Flutter UI on top of a thin
**native Android (Kotlin) bridge** that talks to the DJI MSDK over platform
channels. It covers the core "sample app" flow: SDK registration, product
connection, and live telemetry (battery, GPS, flight status).

> **Android only.** The DJI MSDK V4 native libraries here are wired up for
> Android. iOS would need a parallel Swift/Obj-C bridge (and a Mac to build).

## Architecture

```
┌────────────────────────┐        platform channels        ┌─────────────────────────┐
│ Flutter (Dart)         │  dji_msdk/methods  (MethodChannel)│ Android (Kotlin)        │
│  lib/main.dart         │ ───────────────────────────────▶ │  DjiSdkBridge.kt        │
│  lib/dji_service.dart  │  dji_msdk/events   (EventChannel) │   └─ DJI Mobile SDK V4  │
│                        │ ◀─────────────────────────────── │  DjiApplication.kt      │
└────────────────────────┘                                  └─────────────────────────┘
```

| File | Responsibility |
| --- | --- |
| `lib/dji_service.dart` | Dart wrapper over the method/event channels |
| `lib/main.dart` | UI: registration / connection / telemetry cards |
| `android/app/.../DjiApplication.kt` | Installs the Secneo `Helper` (required by MSDK V4) |
| `android/app/.../MainActivity.kt` | Hosts the bridge, requests runtime permissions |
| `android/app/.../DjiSdkBridge.kt` | Registration, product lifecycle, telemetry callbacks |
| `android/app/build.gradle` | DJI deps, native-lib packaging, multidex, ABI filters |

## Prerequisites

1. **Flutter** (stable) and **Android SDK** with a connected **Android device**
   (the DJI SDK does not work on emulators).
2. A **DJI drone + remote controller** supported by MSDK V4 (Phantom 4,
   Mavic 2 / Air / Mini 1, Spark, Inspire 2, etc.). The RC connects to the phone
   over USB.
3. A **DJI App Key** (see below).

## Set your DJI App Key

SDK registration will fail without a valid App Key bound to this app's
application id.

1. Sign in at <https://developer.dji.com/user/apps/> and create a new app.
   - **Package name** must be exactly: `com.dji.flutter.dji_msdk_sample`
   - SDK: **Mobile SDK**
2. Copy the generated **App Key**.
3. Paste it into [`android/gradle.properties`](android/gradle.properties):

   ```properties
   DJI_API_KEY=your_real_app_key_here
   ```

   The key is injected into `AndroidManifest.xml` at build time via a
   `manifestPlaceholder` (`com.dji.sdk.API_KEY`).

## Run

```bash
flutter pub get
flutter run            # device must be plugged in
# or just build the APK:
flutter build apk --debug
```

## Using the app

1. Launch it and grant the location / phone / mic permissions it requests.
2. Tap **Register app** — needs internet on first run; status turns green on
   success.
3. Connect the drone's remote controller to the phone over USB and power on the
   aircraft. The app auto-starts a connection on successful registration; you can
   also tap **Connect to product**.
4. Once an aircraft connects, the **Telemetry** card streams battery %, GPS
   satellite count, flight mode, altitude, and position.

## Notes & gotchas

- MSDK V4 version is pinned to `4.18` (`com.dji:dji-sdk` / `dji-sdk-provided`).
- `android.enableJetifier=true` is required — the SDK still uses legacy support
  libraries.
- The native `.so` files are kept unstripped and de-duplicated via the
  `packaging { }` block in `android/app/build.gradle`; only `armeabi-v7a` and
  `arm64-v8a` ABIs are bundled (the only ABIs DJI provides).
- This sample uses the **core** SDK, not the DJI **UX SDK** (its native UI
  widgets don't embed cleanly in Flutter).