USB analyzer - Page 1
Forum section: electronics / projects

author: trampas
author_rank: Regular Contributor
timestamp: February 28, 2025, 05:50:26 pm
content: I am doing some USB driver work. I have been having issues with USB working sometimes and not others, as such I am looking for a good logic analyzer for USB.I have a Saleae Logic Pro and it works great, but it is a bit hard to decipher the USB analyzer/plug in. There is just so many packets and trying to figure out where things go off the rails is hard.I have a Total Phase Beagle USB 12 protocol analyzer and it does a good job of showing some data, but does not really help on timing issues. I have the Cynthion device from Great Scott Gadgets and it is more like the Beagle analyzer.I saw that Sigrok had a pretty neat looking decoder,I was wondering if anyone had a recommendation on what is a good tool for USB diagnostics?Note I am amazed no one makes a tool that really analyzes the data, for example inspects the device descriptors and analyzes the data and packets and point out areas of concern. For example I had device descriptors wrong and I would have thought the analyzers would notice the error. Also I have an issue where I think one of my composite devices is being starved of the processor and causing the USB host to reset the bus. Again something I would expect an analyzer would help with.Again I am fairly new to USB so most of these problem might just be novice learning items?Thanks

author: ataradov
author_rank: Super Contributor
timestamp: February 28, 2025, 09:04:02 pm
content: My USB analyzer works quite well -https://github.com/ataradov/usb-snifferThere are multiple vendors on AliExpress that sell the hardware.https://www.aliexpress.us/item/3256807265784243.html?gatewayAdapt=glo2usawas evaluated and shows good results (https://github.com/ataradov/usb-sniffer/discussions/49).Although this is roughly equivalent to Beagle, which is as industry standard as it gets, so if it did not work for you, you are likely doing something wrong.

author: Smokey
author_rank: Super Contributor
timestamp: February 28, 2025, 09:47:47 pm
content: You could use an OpenVizsla... oh, wait... nevermind..https://www.eevblog.com/forum/crowd-funded-projects/openvizsla-still/

author: trampas
author_rank: Regular Contributor
timestamp: March 01, 2025, 12:34:05 pm
content: Thanks!I found that the Saleae and just looking at the traffic which some GPIO pins allowed me to figure out I was not servicing USB fast enough. The Beagle and Cynthion did not provide this information. Sigrok looks like it has a better decoder than Saleae does, however getting sigrok to work with my existing hardware is PITA on window. Sigrok said it would work with Saleae Pro but it lied and could not connect, most likely Saleae had a firmware update or something.Cynthion would be great if it worked with sigrok.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: March 01, 2025, 06:21:18 pm
content: Getting Sigrok to work with saleaeaeeae things is a bit of a nuisance, as it is with other FPGA devices. On startup, the PC has to load the FPGA image into the device, and those FPGA images are not part of Sigrok.I have the Kings LA2016 Logic analyzer, and this has pretty much the same issue. I had to use a Python script to extract the FPGA image from the original software, and put it in a place where Sigrok can find it. After that the LA2016 works with Sigrok without problems.