Windows下的DJI OSDK

Question

I'm trying to get the DJI OSDK up and running from windows environment, but am hitting a few road blocks along the way. Know the SDK has been published for Windows 10, but not yet including the .Net API for M200 / 600 (what I'm trying to interface).

So I first figured my best chance for getting it running on Windows is by trying to run a linux sample application from windows (via Visual studio 2017). Struggled with linux dependencies in the beginning but eventually figured it out by writing a Windows Serial conn class and including pthread.dll for windows (with some minor additional alterations and included #if _WIN32 etc...)

After quite a bit of coding and debugging (also tried Qt sample app via VS tools - whole can of worms on it's own), I'm still struggling with my "Hello world" application from the drone / RPA. (Even the rest works where I export it to a DLL and implement in c# environment, but besides the point).

After connecting to the platform (basically initialization and serial port opening) the Activate function sends your app ID + key to the RPA and receives an acknowledgement: This being my code:

    bool threadSupport = true;  //disable first so that able to debug
    vehicle = new Vehicle(Port, baud, threadSupport, AdvancedSensing);

    //test if connection works fine
    if (!vehicle->protocolLayer->getDriver()->getDeviceStatus())
    {
        //not working, delete current instances
        delete (vehicle);
        vehicle = nullptr;  //set back to null pointer
    }

    DJI::OSDK::Vehicle::ActivateData actData;
    actData.ID = appID;
    actData.encKey = new char[65];
    strcpy(actData.encKey, key);
    actData.version = getFWVersion();

    ACK::ErrorCode ack = vehicle->activate(&actData, 1);

The activation function returns 'invalid feedback':

STATUS/1 @ DJI::OSDK::Win_serial_device::init, L47: Attempting to open device COM21 with baudrate 230400...

STATUS/1 @ DJI::OSDK::Win_serial_device::init, L75: ...Serial started successfully.

ERRORLOG/1 @ getDroneVersion, L1378: Drone version not obtained! Please do not proceed. Possible reasons: Serial port connection:

• SDK is not enabled, please check DJI Assistant2 SDK -> [v] Enable API Control.

• Baudrate is not correct, please double-check from DJI Assistant2 -> SDK -> baudrate.

• TX and RX pins are inverted.

• Serial port is occupied by another program. * Permission required. Please do 'sudo usermod -a -G dialout $USER' (you do not need to replace $USER with your username). Then logout and login again

ERRORLOG/1 @ activate, L1267: Unable to initialize some vehicle components! STATUS/1 @ getErrorCodeMessage, L656: Activate STATUS/1 @ getCommonErrorCodeMessage, L722: ACK_NO_RESPONSE_ERROR

...Already checked the suggested issues, but can't pick up anything apparent. At this point not knowing if the problem is hardware-, software (with altered code and threading). If anyone with DJI platforms (M-range), or on the DJI dev. team can please assist? I'm desperate to get this working! :(

I've also shared the code solution on Github DJI OSDK Win Console

Answer 1

Hi Im shenghai and I have been running DJI hardware for non-GPS/LIDAR/Vision based autonomous research for 3 years.

It is a typical problem which DJI wont tell you the full list. Here is a checklist that I come up with

(1) Connect API cable first. Then Run OSDK. then connect simulator cable then run DJI assistant. There is proper sequence shit which DJI don't feel obliged to share.

(2) Ensure your cable is 3.3, not 5

(3) Tx Rx swap. Common problem. Can check by realterm

(4) Ensure your DJI go app is running and the controller is powered on b4 start serial connection

(5) Ensure app id and enc key is correct. And the account this id and key are associated is also running in ur tablet. We encounter this issue for some special compassless firmware, if you have close relationships with DJI they will provide u with lots of shit to test.

(6) Ensure your Serial have authority. In ubuntu is sudo chmod a+rw /dev/serial/by-id/usb-XXmanufactoridXX-port0. Windows forgot. haven`t use it for years

(7) Ensure your API is enabled in DJI assistant. Also for a quick check, disconnect and connect to the assistant, ensure API is still checked. We have a bad experience with it. No matter how many time i check, it went uncheck. Took us a while to find the bug

(8) Ensure you are running current Assistant 2. For matrix should be DJI assistant for Matrix. For a different drone, there is a different version. I know its complex. no idea why they do so.

(9) Ensure you OSDK build is complete and functional. No missing dependency or funny errors. It happens a lot with new 3.7 and 3.8 stereo vision system

That's pretty much all I can think so far.