# PX4 Community Q&A: June 14, 2023 **URL:** \ **Category:** PX4 Autopilot\ **Created:** [June 7, 2023, 5:00pm UTC](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616 "2023-06-07T17:00:14Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![rroche](https://discuss.px4.io/user_avatar/discuss.px4.io/rroche/32/17635_2.png) [@rroche](https://discuss.px4.io/u/rroche)\ **Post date:** [June 7, 2023, 5:00pm UTC](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616/1 "2023-06-07T17:00:14Z")
# June 14, 2023 ## Join us > **[Discord - Group Chat That’s All Fun & Games](https://discord.com/channels/1022170275984457759/1022185721450213396/1065287189791002776)** > > Discord is great for playing games and chilling with friends, or even building a worldwide community. Customize your own space to talk, play, and hang out. ## Agenda - Community Announcement - Community Q&A - General Discussions ## 📢 Community Announcement * * * ### A.1 : ## 🧑‍🤝‍🧑 Community Q&A (No deep technical discussions) * * * ### ❗ Guideline for asking a Question 1. Specify what you are trying to **achieve** 2. Specify what environment / **platform** you are using 3. Prepare a **Link** or **Document** to help understand if possible 4. First, ask the question on **Discord** or [create a **Github Issue**](https://github.com/PX4/PX4-Autopilot/issues/new/choose)! 5. If you take over 5 minutes for the question, please continue in Discord or a Github Issue. ### Q.1 : Iridium driver malfunctioning - Ludovic > [@PX4 Community Q&A: June 14, 2023](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616/2): > > Hi, we just did a “weather balloon” flight with PX4 a couple of weeks back and had a critical bug in the Iridium driver which result in a failed flight. In the logs, we can see that the states of the Iridium driver “hang” for about 40 minutes. It then recovers and after a while stop completely. Which you can see in the last graph in the picture: Here’s the log for anyone that wants to look at it in detail, here’s the link to the log: [log\_55\_2023-5-31-16-04-32.ulg - Google Drive](https://drive.google.com/file/d/1cH5qz4L-_KIkcqJ3vI1IUSXuTISNxftQ/view) Sadl… - Long duration High altitude balloon test - Iridium driver state is switching to idle, hangs, and works, then hangs, and then doesn’t continue functioning. - Flight log is 800+ MB, so couldn’t upload to flight review - Also, thermistor topics were logged `iridiumsbd_status` message stopped, then continued working. Question: Was the modem actually working? Is it actually communicating with the modem during the period it ‘hangs’? Action Item: - Figure out the structure of the module handling the iridium module communication & test via hardware on what happens when modem disconnects, etc. - Check if there are extra metrics in the modem that can be analyzed in PX4 side, to debug this ### Q.2: MAVLink stream of a custom message not working - Ludovic > [@PX4 Community Q&A: June 14, 2023](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616/3): > > Hi, I have another question. I’m trying to plot a new MAVLink message inside QGC with the MAVLink Inspector view, but I’m not able to see it on the QGC side. I have a new MAVLink stream being output on the USB connection on the Pixhawk hardware. And I’ve tested it with another interface to make sure that it is actually publishing data. And I can also see it when I execute the mavlink status streams command: And I’m sure I need to update the C library that QGC is using so that it will… Currently trying to do check Iridium SBD message via MAVLink stream, as checking the status after downloading uLog is too time consuming. Discussion: - Could try Wireshark for checking if data is coming through at least. The message: [MAVLINK Common Message Set (common.xml) | MAVLink Guide](https://mavlink.io/en/messages/common.html#ISBD_LINK_STATUS) QGC MAVLink generation part: [qgroundcontrol/src/AnalyzeView/MAVLinkInspectorController.cc at aa0f2c61b2c0dbf1913f1f8186312811ca7dbdeb · mavlink/qgroundcontrol · GitHub](https://github.com/mavlink/qgroundcontrol/blob/aa0f2c61b2c0dbf1913f1f8186312811ca7dbdeb/src/AnalyzeView/MAVLinkInspectorController.cc#L564) ### Q.3: Precision landing not working - Ivan - There are parameters to configure to use precision landing. - For some reason, landing target estimator parameter isn’t showing up. If the precision landing is not working with the drone check for this: 1. Open QGC 2. Click on QGC icon on the top right corner 3. Select Vehicle Setup 4. Click on Parameters tab from the left column 5. on the search bar look for SENS\_EN\_IRLOCK and for LTEST 6. If none of those shows then it is possible that Landing Target Estimator is not running. To fix this we will do: 1. Open QGC 2. Click on QGC icon on the top left corner 3. Click on Analyze Tools 4. Click on MAVLink Console 5. Create a folder ```auto mkdir /fs/microsd/etc ``` 1. Create a extras.txt file on the new folder ```auto echo irlock start -X >> /fs/microsd/etc/extras.txt ``` ```auto echo landing_target_estimator star >> /fs/microsd/etc/extras.txt ``` There’s a workaround solution here for example: [irlock doesn't work with the irlock Pixy camera · Issue #10210 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/issues/10210#issuecomment-889213666) Feedback: Make sure to also check especially the first pr of these: - Check this one specifically and potentially test it out (not sure if it’s up to date now) [https://github.com/PX4/PX4-Autopilot/pull/18973](https://github.com/PX4/PX4-Autopilot/pull/18973) - [Add separate precision landing library. by KonradRudin · Pull Request #20645 · PX4/PX4-Autopilot · GitHub](https://github.com/PX4/PX4-Autopilot/pull/20645) For now, irlock & precision landing wasn’t being actively maintained, so it may be broken as well. Also, e.g. landing target estimator probably should be broken out for different sensors (e.g. UWB, Ir lock, etc) - Daniel Action Item: - Ivan will submit the issue to the PX4 repository This check should access the parameter, hence the parameter should get flaged active and advertised to the ground station: > ### Q.4: ROS2 multi vehicle simulation - Aly Using [PX4 Guide (main)](https://docs.px4.io/main/en/ros/ros2_multi_vehicle.html), the namespaces aren’t configured correctly (separated out). How environment variables work/ where to find that info? Link to discord questions: [Discord](https://discordapp.com/channels/1022170275984457759/1030186476153085993/1118432400662335518), [Discord](https://discordapp.com/channels/1022170275984457759/1030186476153085993/1118539410854649917) More details: The note in the documentation highlights the issue that the first instance (px4\_instance=0) does not have an additional namespace in order to be consistent with the default behavior of the xrce-dds client on a real vehicle. I am using `sitl_multiple_run.sh` and the issue is sitll present Question: Where’s the list of topics communicated through DDS? - Currently it’s a static YAML file under the dds module. Also, when using multi-vehicle simulation, the DDS topics list are getting redirected (Standard IO), compared to when doing single vehicle simulation. Note, getting the PX4 node wrapped properly and removing the multi vehicle script with arbitrary indexing conventions, etc would resolve our pain point long term as well - Daniel Action Item: - Have an issue tracking this by Aly - Create CI workflow to make sure we support this multi-vehicle via DDS supported ### Q.5: ROS2 Humble and Docker support Answer: We aim to have them in a single container & switch over to Long term support ROS2 version as well. This was also discussed here: [PX4 Maintainers Call: June 13, 2023](https://discuss.px4.io/t/px4-maintainers-call-june-13-2023/32587#docker-containers-for-px4-benjamino-5) ## 🤔 General Discussions * * * ### D.1 : ---
**Author:** ![LudovicVanasse](https://discuss.px4.io/user_avatar/discuss.px4.io/ludovicvanasse/32/13659_2.png) [@LudovicVanasse](https://discuss.px4.io/u/LudovicVanasse)\ **Post date:** [June 12, 2023, 2:43pm UTC](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616/2 "2023-06-12T14:43:56Z")
Hi, we just did a “weather balloon” flight with PX4 a couple of weeks back and had a critical bug in the Iridium driver which result in a failed flight. In the logs, we can see that the states of the Iridium driver “hang” for about 40 minutes. It then recovers and after a while stop completely. Which you can see in the last graph in the picture: ![image](https://discuss.px4.io/uploads/default/original/2X/4/405838d36a4f6ad3d6da12e0e6d9679adb830da2.png) Here’s the log for anyone that wants to look at it in detail, here’s the link to the log: [log\_55\_2023-5-31-16-04-32.ulg - Google Drive](https://drive.google.com/file/d/1cH5qz4L-_KIkcqJ3vI1IUSXuTISNxftQ/view) Sadly, I wasn’t able to upload it to the flight preview website. There’s the tmp61\_thermistor topics that are thermistor inside the gondola to give us better temperature sensing of what’s going on in the gondola. Basically, I’m kind of asking if anyone has an idea of what might of happen and how to fix it? Thank you! Ludovic ---
**Author:** ![LudovicVanasse](https://discuss.px4.io/user_avatar/discuss.px4.io/ludovicvanasse/32/13659_2.png) [@LudovicVanasse](https://discuss.px4.io/u/LudovicVanasse)\ **Post date:** [June 13, 2023, 9:18pm UTC](https://discuss.px4.io/t/px4-community-q-a-june-14-2023/32616/3 "2023-06-13T21:18:45Z")
Hi, I have another question. I’m trying to plot a new MAVLink message inside QGC with the MAVLink Inspector view, but I’m not able to see it on the QGC side. I have a new MAVLink stream being output on the USB connection on the Pixhawk hardware. And I’ve tested it with another interface to make sure that it is actually publishing data. And I can also see it when I execute the `mavlink status streams` command: ![image](https://discuss.px4.io/uploads/default/original/2X/6/6de8afcef07c2cbc6fe25083dbe85aaa929ec6ea.png) And I’m sure I need to update the C library that QGC is using so that it will have the proper header to decode the msg. So I executed the `python3 -m mavgenerate` and generate the header with version 2 in C to the root of the c\_library\_v2 folder. Also, my new message is inside common.xml. Then I simply compile QGC with the docker instruction `docker run --rm -v ${PWD}:/project/source -v ${PWD}/build:/project/build qgc-linux-docker`. But then when I look into the MAVLink inspector, I’m not seeing anything regarding my streams ☹ . There’s this issue that mention it, but there doesn’t seem to have clear answer for me: [New MAVLink message implementation to QGroundControl · Issue #2731 · mavlink/qgroundcontrol · GitHub](https://github.com/mavlink/qgroundcontrol/issues/2731) Any help would be appreciated 🙂! Thank you again, and sorry if I’m asking too many questions 😓. Ludovic