ModalAI Forum

Can you share a picture of your setup? Is the Quectel RM502Q-AE installed?

We have not done a direct comparison. In general though, all of those systems typically achieve 1-1.5% drift over distance which is something we see pretty consistently with the qvio-server

Thanks for posting the ssl fix. We're looking into this. We don't typically use rosdep for anything. Is there something specific you need to get working?

A more traditional ROS experience is easy to achieve running Ubuntu in a Docker on VOXL : https://docs.modalai.com/docker-on-voxl/

Your understanding is correct, ModalAI's supported configurations are a result of Qualcomm limitations

It would have shipped with everything tested and working. What do you mean by "passed the wizard"?

The system was tested in VIO mode for 20 minutes before shipping. All drones are very sensitive to frame modifications, so this needs to be done carefully

• Were you able to fly successfully before frame modifications?
• How well does it fly manually? Have you looked at the logs in manual.mode for vibration?
• Can you please share a log of the VIO output?
• If you reset all of the software, you may need to recalibrate the cameras
• It looks like there are loose parts hanging off of the drone. VIO is VERY sensitive to vibration. Can you revert your frame modifications and try again?

You should be able to use the open source PX4 avoidance, but it may require a bit of an atypical architecture. When trying to use big ROS projects we recommended running Ubuntu on VOXL in Docker

The base Yocto layer should be ROS core and expose the VIO and depth from stereo modules:

• voxl-cam-ros
• snap_vio
• depth-from-stereo

Then the Ubuntu OS in the Docker should subscribe to the appropriate hardware layer topics to execute the PX4 Autonomy

We should have this better documented, but keep asking on this thread and we'll try to get you going. Shouldn't be any major blockers, but a few tweaks are probably necessary.

Are you flipping the fastboot switch back? Your symptom is consistent with leaving the fastboot switch engaged instead of setting it back to normal after a few seconds

Might be worth watching the tutorial here if you're unsure

We do not have a thermal option available today, though the Flir Boson and Lepton have been integrated by customers in the past using USB

Stereo cameras need to be co-planar and mounted rigidly. Then they need to be calibrated. Otherwise you should be able to mount wherever convenient

You can see an example of how to write telemetry on top of a video frame here
https://gitlab.com/voxl-public/modal-pipe-architecture/voxl-qvio-server/-/blob/master/server/main.cpp#L715

We haven't tried the Avoidance stack in a while, so it's probably going to come down to what you are more comfortable with. If you are comfortable with Gazebo, SITL might be a good way to go.

The trick with ROS always comes down to making sure all of the nodes are talking to each other. There is a good tutorial on debugging ROS here

You'll want to have a list of the ROS topics the Ubuntu PX4 Avoidance stack requires, and then a list of the ROS topics the yocto base layer is providing. Then you'll need to map the two together.

You should only have one roscore, which should likely be in the Yocto layer. Your PC implementation should be able to see that if you have ROS_IP, etc configured properly.

The most valuable tool right now will probably be rostopic list and rostopic echo. Run ros topic on each of the layers:

• yocto base layer
• Ubuntu Docker
• PC workstation

Make sure you see the proper topics in each location and that they are publishing data.

Regarding stereo, I don't think that PX4 docs section is applicable. That RosDfsExample node should already be publishing a disparity map and point cloud. You can see it is publishing the disparity map here and point cloud here

For VIO use voxl-inspect-qvio

For GPS use voxl-inspect-gps

The source code for those is here

It is not something we have direct support for since the flight controller is built in.

Here is how you connect VOXL to an external flight controller: https://docs.modalai.com/how-to-connect-voxl-to-pixhawk/

The normal UART is not exposed on VOXL Flight, so you would have to modify the code on VOXL to use a different UART

VOXL Connectors

ModalAI technical documentation for VOXL and VOXL 2 Companion Computers for PX4 and ArduPilot Obstacle Avoidance and GPS-denied navigation, assembled in the USA

ModalAI Technical Docs (docs.modalai.com)

Why use Docker for this? voxl-logger is setup to do this for you already

It is the way for software to tell which TOF driver should be used. Setting to 1 supports the HAL3 method you are using, setting to 0 supports the older libCamera method using tof_cam_ros

The HAL3 method is intended to give the developer more control over the pipeline

Have you looked at the video tutorial here? https://docs.modalai.com/configure-extrinsics/

You will need to change the code in voxl-vision-px4 to use a different UART. I don't think betaflight supports mavlink though as a control mechanism. What are you hoping to connect between VOXL and betaflight?

Please review the External UDP Mavlink Connection documentation

Assuming the ipk is installed, can you please then run this command and then try the ROS node again?

setprop persist.camera.modalai.tof 1

posted a few basics in the docs https://docs.modalai.com/voxl-tflite-server/

You can see exactly where the image comes in her: https://gitlab.com/voxl-public/modal-pipe-architecture/voxl-tflite-server/-/blob/master/server/threads.cpp#L105