Camera orientation parameter

[Alex Kushleyev]

In order to flip orientation of IMX214 camera (actually it's a 180 degree rotation), you can do this by editing the camera configuration file:

• edit file /system/etc/camera/camera_config.xml (make sure to create a backup of the config file first)
• replace <SensorName>imx214_rot180</SensorName> with <SensorName>imx214</SensorName> - there should be several occurrences.
• this will load a different camera driver, which instructs the camera to flip the image before sending to VOXL
• actually, the default configuration in camera_config.xml is flipped/rotated for imx214, as you can see, because the way the camera is built, the image would show up flipped if using <SensorName>imx214</SensorName> on standard VOXL Flight Deck

For stereo cameras, I would suggest go ahead and try to follow this procedure for calibrating: https://docs.modalai.com/calibrate-cameras/#calibrate-stereo-cameras . This will calibrate the ov7251 camera intrinsic parameters and relative translation + rotation of the two stereo cameras in the pair. Hopefully this succeeds (like I said we have not tried rotating both stereo cameras 90 degrees, but in principle it should work). After that, you will also need to adjust the rotation of the stereo pair with respect to the drone itself, if you want to put the depth points in the correct frame. However, even before doing that last step, you can still check if stereo is working by looking at the resulting point cloud.

[Alex Kushleyev]

Also, make sure to reboot VOXL after you change camera_config.xml

[afdrus]

@Alex-Kushleyev I don't have any camera_config.xml file in the path that you specified, and it does not get created when using voxl-configure-cameras neither. Therefore, how can I change the rotation of the hires/stereos? In voxl-portal they keep being flipped.

[Alex Kushleyev]

@afdrus , the original thread was related to VOXL1. Is your question about VOXL1 or VOXL2?

Alex

[afdrus]

@Alex-Kushleyev, sorry, I missed that, my question is about VOXL2

[afdrus]

@Alex-Kushleyev then, how can I change the rotation of the hires/stereos? In voxl-portal they keep being flipped. Is it only possible to rotate the mounting of the cameras?

[Alex Kushleyev]

@afdrus please check the bottom of this thread how to rotate the hires (IMX214) camera:

Voxl-streamer rotation

@hmlow Glad it worked! For future reference, the imx214_flip driver should be available internally from SDK 1.1 (system image 1.7) onwards. Rather than downl...

ModalAI Forum (forum.modalai.com)

@modaltb do we also have rotation option for the stereo cameras (are we building rotated ov7251 drivers?)

Alex

[modaltb]

@afdrus,

We're trying to improve customizability... our approach now is we're shipping various flavors of sensors/variants/HW locations....

TLDR: here's pre-release binaries to try, these go into /usr/lib/camera:

https://storage.googleapis.com/modalai_public/forum/2023-08-18-imx214-flip/com.qti.sensor.imx214_flip.so
https://storage.googleapis.com/modalai_public/forum/2023-08-18-imx214-flip/com.qti.sensormodule.imx214_flip_0.bin
https://storage.googleapis.com/modalai_public/forum/2023-08-18-imx214-flip/com.qti.sensormodule.imx214_flip_2.bin
https://storage.googleapis.com/modalai_public/forum/2023-08-18-imx214-flip/com.qti.sensormodule.imx214_flip_3.bin
https://storage.googleapis.com/modalai_public/forum/2023-08-18-imx214-flip/com.qti.sensormodule.imx214_flip_4.bin

---

Longer version: we've started docs here: https://docs.modalai.com/voxl2-image-sensors/

Starting in SDK1.0, we began to put the sensor MODULE bin options in /usr/share/modalai/chi-cdk.

These are the binaries that tie the HW location, and also is in charge of pulling in the appropriate sensor SO in /usr/lib/camera

voxl2:/usr/share/modalai/chi-cdk$ ls
imx214  imx214-flip  imx335  imx377  imx412  imx678  irs1645  ov7251  ov7251-combo  ov7251-combo-flip  ov7251-fsin  ov7251-fsout  ov9782  ov9782-combo  ov9782-combo-flip

For example, this is our preview release, there's imx214-flip.

The idea is, you want to find the appropriate bin to use, for example my options:

voxl2:/usr/share/modalai/chi-cdk$ ls imx214-flip/
com.qti.sensormodule.imx214_flip_0.bin  com.qti.sensormodule.imx214_flip_2.bin  com.qti.sensormodule.imx214_flip_3.bin  com.qti.sensormodule.imx214_flip_4.bin

The so that will be used by these bins is /usr/lib/camera/com.qti.sensor.imx214_flip.so.

[modaltb]

@afdrus , @Alex-Kushleyev ,

Just realizing you asked for STEREO sensors haha, those should be on target already and found under /usr/share/modalai/chi-cdk/ov7251-combo-flip....

[afdrus]

@modaltb Thanks, despite the delay, for the response! I only have one last question in this regard: is it possible to rotate the stereo ov7251 by 90 degrees or currently it is only possible to flip them by 180?
This info would help me a lot. Thanks!