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• VOXL-CAM

  Discussion regarding VOXL-CAM

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  @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

  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"
• VOXL Flight Deck
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  A

  @mkriesel , we do not have enough information to be able to pinpoint the root cause, so please try to perform the following test:

  on voxl2

  systemctl stop voxl-px4 cd /usr/share/modalai/voxl-esc-tools ./voxl-esc-scan.py

  The output should look similar to this . Run this scan back to back several times and check if all 4 ESCs are detected each time.

  If the esc scan result on voxl2 is not consistently detecting all 4 ESCs, please repeat the same test on a linux PC (you will need the aforementioned UART cable). You can download voxl-esc tools from the git repository here and run the same test, the output should look like this -- almost identical to what is expected when scanning on voxl2.

  Thank you

  Alex