How can I downgrade my UHD Version from USRP on a custom installation (R2022b) ?

I have two laptops that I am running Universal Software Radio Peripheral (USRP) on. I have two X310 radios that are connected to the laptops, both of which are the same make and have the same version of MATLAB R2022b installed.

I was able to download USRP Hardware Driver (UHD) version 4.1.0.4 on the first laptop with no issue, and using the getSDRUDriverVersion command verified this for me.

However, on the other laptop, the USRP Package installed the UHD version 4.3.0.0 release. I installed this new release as it was the newest Ettus release on their github library. While it shows me that the update was successful, I'm not able to get it to function properly. This link below:

https://www.mathworks.com/matlabcentral/answers/1875572-updated-uhd-still-issuing-update-firmware-error

shows what I have already tried in order to get it to work. Because of this, I resorted to manually installing version 4.3.0.0 from the Ettus repository using a third party UHD software. The issue arises from when I run any example files - I get a warning in the form of

Warning: CenterFrequency is out of range

To circumvent this, I've tried to downgrade UHD version 4.3.0.0 to 4.1.0.4 to my laptop. I have tried completely uninstalling MATLAB, including deleting the SupportPackages folder, and reinstalling it. Still, anything I try shows me that the UHD version is stuck to 4.3.0.0. Please let me know how to downgrade my UHD version in MATLAB.

Answer 1

[MathWorks Support Team]

The issue lies within the uhd.dll configuration file present in the <C:\Windows\System32> directory. When one installs the UHD installer from the Ettus repository, this uhd.dll file gets created. However, MATLAB's USRP package installs a different version of UHD. When the uhd.dll file from Ettus is present while MATLAB is trying to install UHD, MATLAB assumes that its UHD version is the same as listed in the DLL file.

When the 'getSDRUDriverVersion' command returns the value listed in the uhd.dll file, it will list the incorrect version. Because of this, the error

Firmware build for the USRP radio is incompatible with the host code build. Update firmware version to X.X.X.X

will show.

To remove this error,

1. Uninstall the MATLAB USRP package
2. Remove the uhd.dll file from the System32 directory
3. Reinstall the MATLAB USRP package

It is important to note that even when one uninstalls the UHD from Ettus, the uhd.dll file persists in the System32 directory. It must be manually removed.