3 x astra_embedded_s camera, cannot run all 3 cameras

[falinuxKr]

• target: aarch64, x86_64

• OS: ubuntu 20.04, 22.04

• ROS_DISTRO: foxy, humble

• issue: need three astra embedded S cameras [(https://shop.orbbec3d.com/Astra-Embedded-S) at a time. Two cameras work pretty well with pre-defined launch file, however, 3th camera does not work at all. Modified launch file added. Pls review it and comment what's wrong.

• what I tried, 1) use USB 3.0 hub with external power supply 2) PCIe to USB 3.0 extension card with separate power feeding 3) monitor USB bandwidth by usbtop

Thanks

• to attach this launch file, I modified file extension from py to txt. multi_camera.launch.txt

[jian-dong]

Hello @falinuxKr what resolution are you using and how many streams are on?

[falinuxKr]

Hello @falinuxKr what resolution are you using and how many streams are on?

Hello @jian-dong, All cameras-RGB, Depth, IR- have 640x480 30fps by default.

Sorry. RGB has 640x480 @30, and depth/ir have 640x400@30.

[jian-dong]

Hello @falinuxKr This resolution setting exceeds the maximum bandwidth of USB 3.0; you can lower the resolution and frame rate and try again.

[falinuxKr]

Hello @falinuxKr This resolution setting exceeds the maximum bandwidth of USB 3.0; you can lower the resolution and frame rate and try again.

Thanks @jian-dong,

Would you look into what I did?

1. USB bandwidth

• depth camera uses USB 3.x and generates about 20MB data sometimes I thought therefore that USB 3.x(5Gbps) bandwidth is enough to cover whole 3 cameras.
• RGB camera uses USB 2.0(HS) and it does not burden to bandwidth, I think

2. recommended resolutions

• depth, RGB and IR camera's recommended resolution to connect 3 Astra Embedded S at a time

Thanks

[falinuxKr]

@jian-dong

I changed Depth to 320x200 @5, and IR to 320x200@5. RGB as it is. According tolist_camera_profile_mode_mode, RGB does not have lower mode than 640x480@30. But failed to see all 3 cameras. Depth and IR of one camera show very low outputs(fps) instead of other 2 cameras.

[zhonghong322]

Please modify the buffer size of the kernel and test it with the following command, making sure to run it with root permissions.

echo 128 > /sys/module/usbcore/parameters/usbfs_memory_mb
cat /sys/module/usbcore/parameters/usbfs_memory_mb

After modifying the kernel buffer size, we tested it with three devices and it worked fine.

[falinuxKr]

@zhonghong322 VERY thanks. You saved lots of time.