(VOXL2 PX4 ROS2) MPA to ROS2 Tag Detection

GlennTee

Hello. I was curious as to how I can get AprilTag detections from the MPA tag-detector service as a ros2 topic?

Zachary Lowell 0

@GlennTee one step ahead of you!

https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-mpa-to-ros2/-/blob/dev/colcon_ws/src/voxl_mpa_to_ros2/src/interfaces/tag_interface.cpp?ref_type=heads

Going to be rleased on the next sdk release - if you want it now, feel free to build and install the package.

GlennTee

@Zachary-Lowell-0 Thank you. I just tried to install and build the package (I wasn't sure in what location to put it in in Voxl2 so I put it in /home/root) and this happened:

I'm not exactly sure where to obtain the missing nlohmann_json library. I tried doing "sudo apt install nlohmann-json3-dev," but had no luck with this.

Zachary Lowell 0

You should be doing cross compilation for things like this - aka on your computer running voxl-docker -i qrb5165-emulator and then building the debian and flashing to the voxl2.

So what I currently do to build is:

clone mpa to ros2 on your parent computer
cd into repository
run voxl-docker -i qrb5165-emulator:1.5
run ./install_build_deps.sh qrb5165 dev
run ./build.sh qrb5165
run ./make_package.sh

Push via adb or scp the deb from parent computer to voxl2 and then unpackage the deb and source the right directory.

LMK if that helps at all - if you need to install nlohmann json btw you should be doing it via voxl-configure-mpa-to-ros2

Zach

GlennTee

@Zachary-Lowell-0 Thank you, I will try this

GlennTee

@GlennTee Hello again. I attempted to run all of these commands, but I ran into an error on Step 5, which is shown below:

I tried cloning the px4_ros_com package, but that did not help anything. I just also realized I never ran "voxl-configure-mpa-to-ros2" when setting up the SDK v1.4.1, could that be the reason why I'm experiencing so many problems and had to manually install packages I didn't have right off the bat such as Colcon, Eigen3, Netiface, and more? My last question is that do you know when the next SDK release will be out? Thanks again for all your help.

GlennTee

@Zachary-Lowell-0 Hello again. I attempted to run all of these commands, but I ran into an error on Step 5, which is shown below:

I tried cloning the px4_ros_com package, but that did not help anything. I just also realized I never ran "voxl-configure-mpa-to-ros2" when setting up the SDK v1.4.1, could that be the reason why I'm experiencing so many problems and had to manually install packages I didn't have right off the bat such as Colcon, Eigen3, Netiface, and more? My last question is that do you know when the next SDK release will be out? Thanks again for all your help.

Zachary Lowell 0

Hi @GlennTee you need to do a git submodule update --init --recursive on the voxl mpa ros2 code base to pull in px4 ros msgs

Zach

GlennTee

@Zachary-Lowell-0 I just tried running that command a few times but I've had no luck. Is there something I'm missing? Thanks again.

tom

@GlennTee You'll want to run that outside of the docker container, before running voxl-docker

GlennTee

@tom Hello, when you mean docker do you mean the emulator? I'm not using a docker of any sorts (as far as I know of), but I did try running the command before the emulator and this is what I got:

tom

@GlennTee yes that's what I meant. You'll have to git clone the repo instead of just downloading it in order for that to work

GlennTee

@tom Hello again. I just tried to run the command to clone the repository and I tried running ./build.sh qrb5165, but I keep getting the same error it looks like. Could you tell me the exact command I need to run in order to clone the repository? I know @Zachary Lowell 0 already outlined the commands I should follow. Thank you again.

GlennTee

@tom @Zachary-Lowell-0 Hello again. It looks like I got the build to work. I tried cloning voxl-mpa-to-ros2 and that seemed to have worked in generating the build. I also ran "git submodule update --init --recursive" to pull in the px4 messages. I tried running "ros2 launch voxl_mpa_to_ros2 voxl_mpa_to_ros2.launch" but I received the following errors as shown below.

These are the ros2 topics that show up for me as well.

Is there something I'm missing that I need in order to see the ros2 topic for AprilTag detection?

GlennTee

@tom @Zachary-Lowell-0 Looks like I got it to work, I was just running the wrong command. Is there an existing topic called "tag_detections" that should be appearing or is there another repository I need to download in order to obtain that? Thank you.