Hi!
I'm testing the onboard SDK with a N3 flight controller.

The drone is a custom build and the vehicle is flying great.

The N3 is using the firmware: v1.7.7.0

The test I'm doing is using the ROS Onboard SDK, I'm aware that version 4.0 of the onboard SDK is not compatible with the N3, but I switch to the branch 3.8.1 which apparently supports the N3.

I have my API cable properly setup with a USB TTL cable to my computer which runs linux and I followed all instructions in the documentation of DJI.

I registered my app in the developer site and I have my app ID and the key, which I installed in two locations:

* /home/user/.ros/UserConfig.txt
* in the ros launch file: `src/Onboard-SDK-ROS/dji_sdk/launch/sdk.launch`

My UserConfig file looks like this:

```

app_id : xxxx

app_key : xxxx

device : /dev/ttyUSB0

baudrate : 921600

```

(I just put xxxx on the id and key for security)

Using the DJI Assistant 2 application, I enabled in the SDK section:

* Enable API Control: active
* Ground Station Status: active
* Enable SDK Failsafe Action: active and set to hover

When launching the sample ros launch file I get the next output:

```
~/catkin_ws$ roslaunch src/Onboard-SDK-ROS/dji_sdk/launch/sdk.launch
... logging to /home/aldux/.ros/log/dc499c4c-af5f-11ea-932b-5c5f67f52409/roslaunch-x1-4783.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://x1:34267/

SUMMARY
========

PARAMETERS
* /dji_sdk/align_time: False
* /dji_sdk/app_id: xxx
* /dji_sdk/app_version: 1
* /dji_sdk/baud_rate: 921600
* /dji_sdk/enc_key: xxx...
* /dji_sdk/serial_name: /dev/ttyUSB0
* /dji_sdk/use_broadcast: False
* /rosdistro: melodic
* /rosversion: 1.14.6

NODES
  /
    dji_sdk (dji_sdk/dji_sdk_node)

auto-starting new master
process[master]: started with pid [4793]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to dc499c4c-af5f-11ea-932b-5c5f67f52409
process[rosout-1]: started with pid [4804]
started core service [/rosout]
process[dji_sdk-2]: started with pid [4807]
[ INFO] [1592263684.701623437]: Advanced Sensing is Enabled on M210.

STATUS/1 @ init, L55: Attempting to open device /dev/ttyUSB0 with baudrate 921600...

STATUS/1 @ init, L65: ...Serial started successfully.

STATUS/1 @ parseDroneVersionInfo, L727: Device Serial No. = xxxx

STATUS/1 @ parseDroneVersionInfo, L729: Hardware = N3

STATUS/1 @ parseDroneVersionInfo, L730: Firmware = 3.3.8.47

ERRORLOG/1 @ initVirtualRC, L1103: Virtual RC is not supported on this platform!

ERRORLOG/1 @ AdvancedSensing, L58: Please make sure the connected drone is a M210 and firmware version is supported.

[ERROR] [1592263686.918042177]: drone activation error
[ERROR] [1592263686.918157802]: Vehicle initialization failed
```


That means the communication between drone and computer is working, as it successfully identifies the N3 and the firmware...

The issue is: drone activation error

I read online that the app needs to be activated using either the Go App or the Assistant 2 app... but my drone does not have LB2, so I cannot use the Go App to activate...

And the assistant 2 app never prompts me for the activation... I'm using version v2.0.3 of the DJI Assistant in windows.

What can I do to proceed and activate my app??


Any help will be appreciated.

Note that you are using N3 flight controller, so you need to switch off the ADVANCED_SENSING function and modify the code dji_sdk_node.cpp as follows:

This is a picture of a reply to an email from DJI, after the modification is saved, recompile it.

yes! thanks, that made it work!