@Alex-Kushleyev I initially tried using an LCD screen for the checkerboard, but the camera wasn't detecting it. Should I move the camera around when transitioning between boxes on the LCD screen? Afterward, I reverted to the physical checkerboard and moved slowly during calibration. Additionally, I switched to the stereo camera configuration (https://docs.modalai.com/voxl2-camera-configs/#c-10-front-stereo-only-ov7251). Calibration completed successfully, and I was able to start the voxl-dfs-server (after renaming the intrinsics/extrinsics files to match the DFS configuration). However, I'm still not seeing valid output data in the VOXL Portal. Both the DFS server status and journal logs appear normal. Any idea what might be causing this? The orientation was labeled vertical in the extrinsics file, I updated it to horizontal since the cameras are mounted in that direction, I tried both. voxl2:~$ voxl-calibrate-camera stereo -s 6x9 -l 0.0254 Waiting for valid pipe... Please open voxl-portal in a web browser to view the camera calibrator overlay stream Running Calibration... Calibrating Left Camera using intrinsics guess for ov7251 stereo cam Matrix [512.0490656858071, 0, 317.943082105687; 0, 512.9677676044445, 249.1010817824914; 0, 0, 1] Distortion [-0.2223760024137635; 0.2834698825913266; 0.006375005556120415; 0.001380405690556171; -0.3234049381178579] distortion_model: plumb_bob Re-projection error reported by calibrateCamera: 0.618295 Calibration Succeded! Calibrating Right Camera using intrinsics guess for ov7251 stereo cam Matrix [499.9941123870856, 0, 302.2300515222531; 0, 500.0159138740167, 197.2845691878148; 0, 0, 1] Distortion [-0.1920328131645855; 0.1661211129668493; -9.2603546772169e-06; -0.0005742159007090549; -0.1386842520292771] distortion_model: plumb_bob Re-projection error reported by calibrateCamera: 0.654897 Calibration Succeded! Calibrating Extrinsics 7 frames will be processed Processing non-fisheye stereo R [0.9998717783469182, -0.01301971984148091, 0.009322754990917012; 0.01315096821001574, 0.9998132816974246, -0.01415816995820597; -0.009136678855605861, 0.01427895782876463, 0.9998563059074108] T [-0.09106229154044132; 0.0003557888497092847; -0.01247277836064075] Re-projection error reported by stereoCalibrate: 0.921971 Detected horizontal stereo pair Distance between cameras: 0.0911 Extrinsics Calibration Succeded! Saved intrinsics to: /data/modalai/opencv_stereo_intrinsics.yml Saved extrinsics to: /data/modalai/opencv_stereo_extrinsics.yml Exiting Cleanly [image: 1745965925691-ce4025ae-5114-4473-ae6a-d9e4862c4b13-image.png] cat opencv_stereo_front_extrinsics.yml %YAML:1.0 --- R: !!opencv-matrix rows: 3 cols: 3 dt: d data: [ 9.9987177834691821e-01, -1.3019719841480912e-02, 9.3227549909170124e-03, 1.3150968210015740e-02, 9.9981328169742456e-01, -1.4158169958205966e-02, -9.1366788556058610e-03, 1.4278957828764632e-02, 9.9985630590741081e-01 ] T: !!opencv-matrix rows: 3 cols: 1 dt: d data: [ -9.1062291540441320e-02, 3.5578884970928471e-04, -1.2472778360640750e-02 ] reprojection_error: 9.2197082833254862e-01 orientation: vertical calibration_time: "2025-04-29 21:24:04" cat opencv_stereo_front_intrinsics.yml %YAML:1.0 --- M1: !!opencv-matrix rows: 3 cols: 3 dt: d data: [ 5.1204906568580714e+02, 0., 3.1794308210568698e+02, 0., 5.1296776760444448e+02, 2.4910108178249143e+02, 0., 0., 1. ] D1: !!opencv-matrix rows: 5 cols: 1 dt: d data: [ -2.2237600241376348e-01, 2.8346988259132661e-01, 6.3750055561204149e-03, 1.3804056905561710e-03, -3.2340493811785792e-01 ] reprojection_error1: 6.1829492384868989e-01 M2: !!opencv-matrix rows: 3 cols: 3 dt: d data: [ 4.9999411238708558e+02, 0., 3.0223005152225312e+02, 0., 5.0001591387401669e+02, 1.9728456918781478e+02, 0., 0., 1. ] D2: !!opencv-matrix rows: 5 cols: 1 dt: d data: [ -1.9203281316458551e-01, 1.6612111296684931e-01, -9.2603546772168998e-06, -5.7421590070905486e-04, -1.3868425202927714e-01 ] reprojection_error2: 6.5489679777844001e-01 width: 640 height: 480 distortion_model: plumb_bob calibration_time: "2025-04-29 21:24:04"

@tom It worked! I tightened the screws, and it turns out it was a hardware issue. I've installed the Tailscale VPN on both the drone and my machine, and I've completed the calibration and binding. However, I'm having trouble starting the camera; it's not turning on in VLC or QGroundControl.

@Moderator If you can provide the serial number of your VOXL CAM (form MXX00000XXX) we can check to see if we have the camera calibration data backed up in our production database and provide it if so.

@Irfan-Usman Sure, see these documents VOXL 1 & VOXL CAM: https://docs.modalai.com/how-to-connect-voxl-to-pixhawk/ VOXL 2 (recommended): https://docs.modalai.com/voxl2-external-flight-controller/

@Moderator Hello, Thank you very much for your prompt response and for providing the link to the datasheet for the VOXL 1 connectors. This information is exactly what I needed. I appreciate your assistance and support.

@Joshua-Ermias yes that would be the easiest way. You can either restart the service with systemctl restart voxl-camera-server or just power cycle your VOXL

@viralp https://docs.modalai.com/image-sensor-flexes-adapters/#extending-mipi-image-sensor-cable-lengths

@Amin-Bassiri There will always be some reprojection error when computing a homography, as long as the error is below 0.5 (which it looks like yours is) you should be totally fine. Let me know if you have any other questions! Thomas

@tom Thank you so much! I was having the exact same problem with @marian. I could connect to the voxl via ssh but could not via adb shell. But could solve it after removing the /etc/udev/rules.d/51-android.rules. Try to remove the file, who are facing the same problem with me.

@Eric-Katzfey Thanks Eric, that makes sense!

Hey @KMillzOG , This doesn't help with your core issue, but I have had success running the ROS2 docker images on RaspiOS on a pi: https://docs.ros.org/en/foxy/How-To-Guides/Installing-on-Raspberry-Pi.html If you're comfortable running your software inside a Docker container, that'll solve your problem. Conveniently, you can also build a docker file for ARM or for X86, so you can run the same software on a more traditional PC or inside a CI pipeline. I also recently noticed that there is still an officially supported Ubuntu image for the Pi. I haven't tried it, but it might be another option. If you have a spare SD card, you could install ubuntu on the spare card, then see if that works for you. Then if it doesn't work you can just go back to the old SD card.

@Moderator Thanks for your quick reply. I'm relieved to be sure. Kind regards,

@Connor-Fuhrman , I am not sure. Please try to enable debug-level logging, so you may see some errors (both in your application) and voxl-streamer. In your application you can add the following : M_JournalSetLevel((M_JournalLevel) debugLevel); example: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-camera-server/-/blob/master/src/main.cpp?ref_type=heads#L301 voxl-streamer already has this option, just need a command line option : https://gitlab.com/voxl-public/voxl-sdk/services/voxl-streamer/-/blob/master/src/main.c?ref_type=heads#L383

@Amber-Elaine-Parker It's missing a TF. After launching ROS Indigo on the VOXL, open a new bash and type: rosrun tf static_transform_publisher 0 0 0 0 0 0 1 map world 10 This is enough to create the world frame and make the ToF sensor PointCloud2 message display on Rviz (if you select the world frame under global options in Rviz). However, it looks like the frame isn't oriented correctly in my case. Editing the parameters of this command might change the orientation of the new world frame. I don't know enough about ROS/VOXL SDK to confidently call this an oversight by the ModalAI team, but there should definitely be a mention that this is required somewhere within the documentation.

@fjksalf If the IP address of the VOXL is 192.168.1.1 then you need to execute export ROS_MASTER_URI=http://192.168.1.1:11311 on the Ubuntu system and then run rviz from the same terminal.

@AP123 voxl-rtsp is no longer supported and is not mentioned in that document, you need to use voxl-streamer

@serge I am also facing the same issue, did you solve it?

@Anubhav same issue here, have you figured it out?