Enabling IMU Stream stops frames from being received in the RGB Stream

[GSNCodes]

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Required Info
Camera Model	D435i
Firmware Version	05.14.00.00
Operating System & Version	Linux - Ubuntu 20.04
Kernel Version (Linux Only)	5.15.0-58-generic
Platform	PC/
SDK Version	2.53
Language	opencv/Python
Segment	Robot

Issue Description

Enabling IMU Stream stops frames from being received in the RGB Stream (As well as Depth Steam). I want to record both IMU and RGB Data. Once we stop the motion module/ IMU Stream we get the image frames again in a while. Any help would be greatly appreciated !

[MartyG-RealSense]

Hi @GSNCodes Does the issue still occur if you only enable RGB and Motion Module, and do not enable Depth? The RealSense Viewer tool has a known issue where enabling three streams simultaneously can cause No Frames Received on one of the streams if one of those enabled streams is the Motion Module.

There is no solution for this in the Viewer except to either not enable the Motion Module or to be careful to only enable two streams simultaneously (RGB and Motion Module, or Depth and Motion Module). This is because the Motion Module is the trigger for the problem, so it does not matter which order the streams are enabled in if one of them is the Motion Module.

If you need to enable three stream types then a workaround in Python is to create two pipelines and place Depth + RGB on one pipeline and the IMU (Motion Module) on its own on the other pipeline, as demonstrated in the script at #5628 (comment)

[GSNCodes]

Hi @MartyG-RealSense Thank you for the quick response. No Frames are received when I enable only the RGB and Motion Module (As shown in the screenshot attached). I have not enabled the Depth module. Is there a fix or workaround to get data from both the RGB and Motion modules?

[MartyG-RealSense]

Thank you for the clarification that you have not enabled Depth. I wanted to make sure that all three streams had not been enabled at some point and then Depth disabled, leaving RGB and Motion Module enabled but the No Frames Received problem still persisting.

I note that the USB connection is shown as 2.1 beside the camera name at the top of the Viewer's options side-panel, indicating that the camera is being detected as being on a slow USB 2 connection and so cannot access the full capabilities that are available on a faster USB 3 connection. Can you confirm please that the camera is plugged into a USB 3 port on your computer. Also, are you using the official 1 meter USB cable supplied with the camera or a longer USB cable of your own choice?

[GSNCodes]

Hi @MartyG-RealSense The problem persists and I have not enabled all the three streams. The camera is indeed plugged into a USB 3 port and I am using the official cable.

[MartyG-RealSense]

What method did you use to install the librealsense SDK, please?

1. From Debian packages.

2. From source code with CMake, patching the kernel with patch script patch-realsense-ubuntu-lts-hwe.sh to provide support for kernel 5.15 (the patch script patch-realsense-ubuntu-lts.sh is not suitable for kernel 5.15).

3. From source code with CMake using the RSUSB backend installation method, which bypasses the kernel and so is not dependent on Linux versions or kernel versions and does not require kernel patching.

[MartyG-RealSense]

Hi @GSNCodes Do you require further assistance with this case, please? Thanks!

[GSNCodes]

Hi @MartyG-RealSense
I used the second method "From source code with CMake, patching the kernel with patch script patch-realsense-ubuntu-lts-hwe.sh to provide support for kernel 5.15 (the patch script patch-realsense-ubuntu-lts.sh is not suitable for kernel 5.15)."

[MartyG-RealSense]

What computer or computing device are you using Ubuntu 20,04 on, please (for example a Raspberry Pi or a desktop / laptop PC). If it is a Raspberry Pi board then they also have known problems related to streaming the IMU, as described at #11089

[GSNCodes]

Hi @MartyG-RealSense
I'm using a Ubuntu 20.04 laptop.

[MartyG-RealSense]

Is the laptop that 20.04 is running on a modern machine or an old one?

The 3rd option presented in #11365 (comment) - building librealsense with RSUSB backend = true - would confirm whether the problem with the RGB stream is related to a conflict between librealsense and the kernel version on your computer. Although librealsense supports kernel 5.15 in general in SDK 2.53.1, some kernel versions of the same generation but with different minor version numbers can work better than others (such as 5.11.28 working but 5.11.30 not working).

[MartyG-RealSense]

Hi @GSNCodes Do you require further assistance with this case, please? Thanks!

[MartyG-RealSense]

Case closed due to no further comments received.