How to debug USB related issues

Projects LimeSDR
1

Hello all,

I’ve had recurring issues with USB, when working with one or more SDRs. Depending on which USB3 port I plug them, they may not all work together.

Is there a way to debug or see what’s happening at the USB level, to understand more what the problem might be, on Linux or Windows?

I also wonder if interference could explain some of the problems, eg if the USB cables of several SDRs are next to each other, or if they pass near other possible sources of interference (PSU, motherboard, …). USB3 cables are supposed to be shielded, but maybe it’s not enough?

2

Hi, could you be more specific, which SDR devices you are using, and are you plugging them directly into the motherboard, or are you using USB hubs? What is the power source for the SDRs, only USB port, or are they externally powered?

3

I’m using LimeSDR USB, some plugged straight on the motherboard, some on PCIe extension boards. They are all powered through USB.

What I usually try is to put one SDR on one USB controller, as I tend to see more issues when they share one controller.

4

LimeSDR-USB can draw quite a lot of power from the USB port, some motherboards don’t like that, and can disable the port, or the port might not be able to provide enough power and the device would brown out. So I guess if your plugging in multiple SDRs in related ports or something like that, it could be a powering issue.
Best would be to provide power to the SDR boards externally, or use through a externally powered USB hub.