Problem with StarTech PEXUSB3S44V USB card [SOLVED]

I have installed the recommended StarTech PEXUSB3S44V USB card in a desktop, but am unable to get the Azure Kinect to work.

I followed the instructions to update the drivers provided here for DepthKit Cinema:

The driver version installed is:
Renesas USB 3.0eXtensible Host Controller - 1.0 (Microsoft)
Driver Date: 10/13/2021
Driver Version: 10.0.19041.1320

In Device Manager, the Azure Kinect is visible:
Azure Kinect 4K Camera
Azure Kinect Depth Camera

But when I try to run DepthKit or the ka4viewer.exe or AzureKinectFirmwareTool.exe, it doesn’t recognize a device.

I get this error with AzureKinectFirmwareTool.exe
PS C:\Program Files\Azure Kinect SDK v1.4.1\tools> .\AzureKinectFirmwareTool.exe -l
== Azure Kinect DK Firmware Tool ==
[2022-01-05 08:44:06.497] [error] [t=2132] D:\a\1\s\extern\Azure-Kinect-Sensor-SDK\src\usbcommand\usbcommand.c (370): find_libusb_device(). Unable to open LIBUSB at index 0
[2022-01-05 08:44:06.498] [error] [t=2132] D:\a\1\s\extern\Azure-Kinect-Sensor-SDK\src\color_mcu\color_mcu.c (74): usb_cmd_create(USB_DEVICE_COLOR_IMU_PROCESSOR, device_index, NULL, &colormcu->usb_cmd) returned failure in colormcu_create_by_index()
Found 1 connected devices:
1: Device “000167713812”
PS C:\Program Files\Azure Kinect SDK v1.4.1\tools>

Hi, @JillBoyce. Sorry to hear your sensors are failing to start streaming. This can be caused by a number of issues. The USB driver you have installed is indeed validated to work with the Azure Kinect, but here are a couple of other items to try:

  • Are you using any USB extenders? If so, bypass them and plug the sensor directly into the StarTech card via the short factory-provided USB cable to ensure the cable isn’t causing the issue.
  • Sometimes other applications, like a web browser, will take exclusive control of the sensor to use as a webcam, so make sure all other applications are closed. Windows will even sometimes use the Kinect’s microphone array as the system’s default audio device, but you can disable the microphone array in Windows Sound Settings to ensure there aren’t any conflicts.
  • You can also reset the Azure Kinect drivers in Windows by removing the sensor, showing hidden devices in Device Manager, and uninstalling the grayed-out Azure Kinect, then plugging it back in.

Try these and let us know if you’re still having issues.

Also, the version of our documentation that you linked to is no longer used. For the latest up-to-date information, see the Documentation pages on our website:

I get a “404 not Found” when clicking on the “Hardware Requirements” link under

This suggestion worked:

  • You can also reset the Azure Kinect drivers in Windows by removing the sensor, showing hidden devices in Device Manager, and uninstalling the grayed-out Azure Kinect, then plugging it back in.

The error is gone and I can view the device.

I have 4 Kinect DK devices that I can plug into the StarTech card. However, I can only get 2 devices to connect at a time. What is the expectation of how many devices I should be able to support with one card?

@JillBoyce, thanks for catching the broken link. It should work now.

The StarTech card supports up to 4 sensors. Can you provide any more detail about the two which aren’t connecting? Are the indicator LED’s on the front or back of the devices lighting up? Can you confirm that all 4 devices are powered with their own AC power supplies? Any and all information about the nature of the connection issue helps to diagnose the cause.

Update: it looks like the problem is due to the USB extender cables. If I plug in the sensors directly to the PC without the USB extender cables, all 4 of them can work.

@JillBoyce Glad you were able to isolate the issue. You can find a list of USB extenders which we have validated to work with the Azure Kinect and StarTech PCIe card here.