_udp and lwip for DDS Micro

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_udp and lwip for DDS Micro


I have developed a simple DDS Micro application. One installed in my labtop running Windows, another into my ARM STM32F469 micro-controller. For the laptop, the transport uses the built-in _udp and the embedded used the lwip. Both were tested using the Admin Console. Here are some observations.

  1. Admin Console is able to display the Participant, Publisher, and the topic of the application running on Laptop.
  2. When clicked over Participant in the Admin Console, it displayed all the unicast and multicast locators
  3. Admin Console is able to display the Participant, but no Publisher and the topic of the application running on the embedded board.
  4. When clicked over the Participant in the Admin Console, we discovered that "metatraffic_unicast_locator" is "empty".

May I know where had gone wrong with the embedded one? Two codes are almost identical except one is using "_udp" (for the laptop), and the other is using "lwip" (lwip is used for the embedded board).

Please help as my project is appraching the deadline and I still cannot get the basic working.

I attached the screen-shots for your reference.



Image icon laptop.png87.18 KB
Image icon embedded.png83.84 KB
Howard's picture
Last seen: 16 hours 33 min ago
Joined: 11/29/2012
Posts: 580


Unfortunately, there's not enough info...it would be great if you were able to post the code for both the Laptop and Embedded versions of the same app. The code that intializes Connext Micro would be sufficient.

Also, for issues like this, it would be useful to have a Wireshark trace so that we can see the packets being sent back and forth from the Windows box to the Embedded box.

Finally, in Windows 10, I've noticed that depending on the network type ("domain", "private", "public") the Windows firewall sometimes block some but not all of the communications needed by DDS.  So discovery runs to a point where applications can find out about each other, but not fully discover for communications.

I suggest to try turning off the Windows firewall (even if you're not running Windows 10) and see if that affects anything.

If not, then when you start your DDS application on your Embedded board, is the NIC card and network stack up and running?  If not, it's possible that Micro may not be able to initialize correctly.

If none of the ideas above help, please send code and wireshark traces...