Hello,
  
  I'm trying to run the Payload SDK sample on a Linux machine. When I  run the sample, it connects to the Skyport V2 successfully, but it  fails to connect to the aircraft (See attached console_output document).  I checked a lot of resources on the internet as well as your PSDK  documentation,  but I cannot find out what can be the problem. Hopefully anyone can help me out with this.
  
  Attached you can find a screenshot of the DJI assistant and a schematic overview of the hardware setup.

Console output:

  
Get current log index: 26

[2441509.205][module_core]-[Info]-[PsdkCore_Init:76]Payload SDK Version : V2.2.1-beta.0-build.315

[2441509.226][module_core]-[Info]-[PsdkCore_WaitAdapterConnection:234]Connect to Skyport V2 or X-Port success

[2441509.246][module_core]-[Info]-[PsdkCore_PrintAdapterSerialNumber:278]Get serial number of Skyport V2 or X-Port is 39CDH6P0010053

[2441509.246][module_core]-[Info]-[PsdkCore_Init:130]Updating PSDK policy file.

[2441509.276][module_aircraftinfo]-[Info]-[PsdkAircraftInfo_GetDevelopmentKitTypeAsyncCallback:483]PSDK adapter type is Skyport V2.

[2441509.458][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 1, retryTimes = 3, cmdSet = 3, cmdId = 253

[2441509.661][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 1, retryTimes = 2, cmdSet = 3, cmdId = 253

[2441509.863][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 1, retryTimes = 1, cmdSet = 3, cmdId = 253

[2441510.065][module_command]-[Error]-[PsdkCommand_SendASyncHandle:866]Command async send error 1

[2441510.065][module_aircraftinfo]-[Warn]-[PsdkAircraftInfo_GetAircraftTypeAsyncCallback:416]get aircraft type timeout.

[2441510.246][module_core]-[Info]-[PsdkCore_Init:133]PSDK policy file update success.

[2441510.746][module_core]-[Info]-[PsdkCore_Init:146]PSDK is connecting aircraft.

[2441511.246][module_core]-[Info]-[PsdkCore_Init:146]PSDK is connecting aircraft.

[2441511.478][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 0, retryTimes = 3, cmdSet = 3, cmdId = 253

[2441511.680][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 0, retryTimes = 2, cmdSet = 3, cmdId = 253

[2441511.747][module_core]-[Info]-[PsdkCore_Init:146]PSDK is connecting aircraft.

[2441511.882][module_command]-[Warn]-[PsdkCommand_SendASyncHandle:858]Command async send retry: index = 0, retryTimes = 1, cmdSet = 3, cmdId = 253

[2441512.084][module_command]-[Error]-[PsdkCommand_SendASyncHandle:866]Command async send error 0

[2441512.084][module_aircraftinfo]-[Warn]-[PsdkAircraftInfo_GetAircraftTypeAsyncCallback:416]get aircraft type timeout.

[2441512.247][module_core]-[Info]-[PsdkCore_Init:146]PSDK is connecting aircraft.

Apparently based on another thread you have to connect the aicraft to DJI Assistant 2, go into the Payload menu and click on 'Bind' whilst you are having you payload running.
Then relaunch your payload and voila

In my case, I am unable to get the "Connect to Skyport V2 or X-Port success" message. Did you connect only the UART port? What is your development board?

Hi, djiuser_gWypjWbOEfA3

I was in the same situation as you.
Did you solve it ?