I'm working on a camera app using Android Camera2 SDK which has button for start/stop recording, and a zoom functionality. I've integrated the DJI mobile SDK and I did the registration with the API key generated from the developer account. When I start the app, I receive a `REGISTRATION_SUCCESS` from `DJISDKManager.SDKManagerCallback()#onRegister()` and the Gimbal is connected through Bluetooth to the phone.

Now the issue is, how can I intercept the hardware button press events from the Gimbal ? For example if I press the hardware record button of the Gimbal, the camera app starts recording.

I tried something like this, but it doesn't work. I couldn't find any documentation about how to receive callbacks when hardware buttons are pressed.

    OSMOMobileHandheldController osmoMobileHandheldController = new OSMOMobileHandheldController();
        osmoMobileHandheldController.setHardwareStateCallback(hardwareState -> {

            switch (hardwareState.getRecordAndShutterButtons()) {
                case IDLE: {
                    Log.e("wkh01", "getRecordAndShutterButtons IDLE");
                    break;
                }
                case RECORD_CLICK: {
                    Log.e(TAG, "getRecordAndShutterButtons RECORD_CLICK");
                    break;
                }
                case SHUTTER_CLICK: {
                    Log.e(TAG, "getRecordAndShutterButtons SHUTTER_CLICK");
                    break;
                }
                case SHUTTER_LONG_CLICK: {
                    Log.e(TAG, "getRecordAndShutterButtons SHUTTER_LONG_CLICK");
                    break;
                }
                default: {
                    Log.e(TAG, "getRecordAndShutterButtons UNKNOWN");
                }
            }

            switch (hardwareState.getZoomState()) {
                case IDLE: {
                    Log.e(TAG, "getZoomState IDLE");
                    break;
                }
                case ZOOM_IN: {
                    Log.e(TAG, "getZoomState ZOOM_IN");
                    break;
                }
                case ZOOM_OUT: {
                    Log.e(TAG, "getZoomState ZOOM_OUT");
                    break;
                }
                default: {
                    Log.e(TAG, "getTriggerButton UNKNOWN");
                }
            }

        });

You cant just create an object. You must call the sdk to get the correct instance.
https://developer.dji.com/api-re ... ager_product_inline

So something like:
DJISDKManager.getInstance().getProduct().getHandheld.....

Thx for the reply, I did like you said

HandHeld handHeld = (HandHeld) DJISDKManager.getInstance().getProduct();         
handHeld.getHandHeldController().setHardwareStateCallback(new HardwareState.Callback() {
            @Override            
            public void onUpdate(HardwareState hardwareState) {
                     switch (hardwareState.getRecordAndShutterButtons()) {
                    case IDLE: {
                        Log.e("wkh01", "getRecordAndShutterButtons IDLE");
                        break;
                    }
                    case RECORD_CLICK: {
                        Log.e(TAG, "getRecordAndShutterButtons RECORD_CLICK");
                        break;
                    }
                    case SHUTTER_CLICK: {
                        Log.e(TAG, "getRecordAndShutterButtons SHUTTER_CLICK");
                        break;
                    }
                    case SHUTTER_LONG_CLICK: {
                        Log.e(TAG, "getRecordAndShutterButtons SHUTTER_LONG_CLICK");
                        break;
                    }
                    default: {
                        Log.e(TAG, "getRecordAndShutterButtons UNKNOWN");
                    }
                }

                switch (hardwareState.getZoomState()) {
                    case IDLE: {
                        Log.e(TAG, "getZoomState IDLE");
                        break;
                    }
                    case ZOOM_IN: {
                        Log.e(TAG, "getZoomState ZOOM_IN");
                        break;
                    }
                    case ZOOM_OUT: {
                        Log.e(TAG, "getZoomState ZOOM_OUT");
                        break;
                    }
                    default: {
                        Log.e(TAG, "getTriggerButton UNKNOWN");
                    }
                }

            }         
});

I get only IDLE state, and I get them randomly, not when I press a button...
In the log I see that handHeld is of time OSMOMobile which is correct because its my Gimbal.
But it didn't work, when I press the button I receive nothing..

It would be awesome that you could help me with this, thank you!

djiuser_b9fA0wj643ey Posted at 6-24 02:32
Thx for the reply, I did like you said

HandHeld handHeld = (HandHeld) DJISDKManager.getInstance().getProduct();         

Sounds like you not connected to the product.
Test with:
https://developer.dji.com/api-re ... ct_connected_inline
And of course you must have connected to the product first, which I exepct you have.
https://developer.dji.com/api-re ... thcompletion_inline

Thank you for your response.

Actually I tried to connect to the Gimbal using BluetoothProductConnector, but I always receive from the onResult(error) callback, error="Param Illegal (255)".
So I tried to connect through the phone's parameter by going to bluetooth and pairing manually to the Gimbal. I tried it using the sample app [Sample Code] and it says connected as you can see the below image


Before calling handHeld.getHandHeldController().setHardwareStateCallback(), I test the connectivity using handHeld.isConnected() and it returns true, so everything is fine.

I tested hardwareState.getStickVerticalDirection() and hardwareState.getStickHorizontalDirection(), by moving the joystick analog and I get approximately the correct values (left/right/up/down)
but all other functions like hardwareState.getZoomState() or hardwareState.getRecordAndShutterButtons() they always return IDLE state. (when I press the record button, for some reason it increases the audio of the phone, and the volume seek bar appears, its like Im pressing the volume button)

These are some logs from handHeld.getHandHeldController().setHardwareStateCallback():

/com.dji.sdk.sample E/wkh01: getRecordAndShutterButtons IDLE
/com.dji.sdk.sample E/wkh01: getZoomState IDLE
/com.dji.sdk.sample E/wkh01: getTriggerButton IDLE
/com.dji.sdk.sample E/wkh01: getModeButton IDLE
/com.dji.sdk.sample E/wkh01: getRecordAndShutterButtons IDLE
/com.dji.sdk.sample E/wkh01: getZoomState IDLE
/com.dji.sdk.sample E/wkh01: getTriggerButton IDLE
/com.dji.sdk.sample E/wkh01: getModeButton IDLE
/com.dji.sdk.sample E/wkh01: getRecordAndShutterButtons IDLE
/com.dji.sdk.sample E/wkh01: getZoomState IDLE
/com.dji.sdk.sample E/wkh01: getTriggerButton IDLE
/com.dji.sdk.sample E/wkh01: getModeButton IDLE

I get these even when I don't press any button.

The model name is: OM5-602S46
Im using the Sample code app to test these hardware buttons callbacks.

It would be great that you could help me on this, we need this in our company.

djiuser_b9fA0wj643ey Posted at 6-26 05:18
Thank you for your response.

Actually I tried to connect to the Gimbal using BluetoothProductConnector, but I always receive from the onResult(error) callback, error="Param Illegal (255)".

ok, I'm only used the sdk on drones, and not over bluetooth.

I don't think I can help you. If I were you, I would investigate why you cant use the sdk connect functionality. As it is now it seems like android sees your bluetooth as an device and might interfear with the events sent. A wild guess though :-/

Hope someone else can chime in.

Thank you Mats, I hope anyone else could help me on this..