WTB: Highspeed USB 2.0 Protocol Analyzer - Page 1
Forum section: electronics / general

author: parawizard
author_rank: Regular Contributor
timestamp: January 11, 2025, 10:43:05 am
content: Troubleshooting a side project and in need of a highspeed USB protocol analyzer. Looking for something cheaper and have my feelers out on eBay. If you have one for sale hit me up.Thanks

author: RoadRunner
author_rank: Frequent Contributor
timestamp: January 11, 2025, 10:47:41 am
content: I would not post any links to ebay or others sites butThere are many Clone of this USB protocol analyzers are on sale on various sites.I would not buy a cone but may be you are interested enough to make your self.https://github.com/ataradov/usb-sniffer

author: parawizard
author_rank: Regular Contributor
timestamp: January 11, 2025, 11:42:37 am
content: Thanks for the suggestion! I did already buy a clone. It may make it to me in a few weeks. I may populate one myself. It would be nice to work with more fleshed out software for this issue. At least wireshark has good filtering.I might grab a cheap Lecroy Mercury T2 used or a Ellisys USB Explorer 200.

author: Kean
author_rank: Unknown
timestamp: January 11, 2025, 12:09:42 pm
content: I have a Chinese clone of ataradov's design, but also a GSG Cythion. Admittedly, I've not used either yet...You should be able to by a Cythion from Crowd Supply pretty quickly.https://www.crowdsupply.com/great-scott-gadgets/cynthion

author: RoadRunner
author_rank: Frequent Contributor
timestamp: January 11, 2025, 02:11:28 pm
content: I am using ataradov's design, it work pretty well. Total Cost is also reasonable.

author: ataradov
author_rank: Super Contributor
timestamp: January 11, 2025, 03:57:37 pm
content: Note that there are a number of vendors selling assembled boards of my design on AliExpress. I don't endorse any of them, but I did evaluate this onehttps://www.aliexpress.us/item/3256807265784243.htmland out of all of them, I can recommend it. It uses correct speed grade FPGA (actually higher than needed) and the performance seems to be as good. The only thing it is missing is a trigger input. It is rarely needed, but still.

author: RoadRunner
author_rank: Frequent Contributor
timestamp: January 11, 2025, 04:30:52 pm
content: Thank you ataradov, I have assembled your Design as I had some fear of fake CYUSB chip on Chinese clone.

author: ataradov
author_rank: Super Contributor
timestamp: January 11, 2025, 04:38:06 pm
content: They are not fake clones, they are legit re-implementations because Cypress are idiots and discontinued the only good product in their whole portfolio instead of improving on it.That CBM9002A performs just as well as the original device. It was used by random shops for fakes in the past, but there is no reason to even look for the original in China, since this re-implementation it is pretty well k known established now.

author: zzattack
author_rank: Regular Contributor
timestamp: January 11, 2025, 08:45:05 pm
content: I'm very content with the 1480A by memberJohn_ITEC.

author: parawizard
author_rank: Regular Contributor
timestamp: January 12, 2025, 05:05:23 am
content: Quote from: Kean on January 11, 2025, 12:09:42 pmI looked at the Cythion but I wasn't sure yet if it's what I would want to order.Quote from: ataradov on January 11, 2025, 03:57:37 pmThis is the exact one that I ordered actually! Glad it is a good one. Thanks for making putting the design out thereQuote from: zzattack on January 11, 2025, 08:45:05 pmI sent ITIC an email about their usb protocol analyzer but haven't received a response yet. I wish there were decoders and an external trigger. Software looks good though otherwise. I might try to snag up a used Lecroy as it has both decoders and an external trigger

author: voltsandjolts
author_rank: Unknown
timestamp: January 12, 2025, 09:02:30 am
content: Quote from: zzattack on January 11, 2025, 08:45:05 pmThe ITIC software (being purpose built for USB analysis) looks much more friendly than wireshark. If John added support for Alex's open capture hardware he could make some sales of software alone.

author: voltsandjolts
author_rank: Unknown
timestamp: January 12, 2025, 09:14:14 am
content: Quote from: ataradov on January 11, 2025, 04:38:06 pmSo this can be used in your design, without any firmware changes? It's drop-in compatible with CY7C68013A?

author: Kean
author_rank: Unknown
timestamp: January 12, 2025, 10:39:24 am
content: FWIW, the one I bought has a Lattice LCMXO2-2000HC-4TG100I (industrial temp grade) and a Cypress CY7C68013A.https://vi.aliexpress.com/item/1005002287272881.htmlThe PCB layout is slightly different to the one that Alex linked above. It looks like they did that to make it a single sided assembly job.I bought this one because it came with a metal enclosure (so a little bit more expensive), but I was slightly put off that they didn't give attribution to Alex.

author: ataradov
author_rank: Super Contributor
timestamp: January 12, 2025, 03:56:55 pm
content: Quote from: voltsandjolts on January 12, 2025, 09:14:14 amYes, it is a full drop-in replacement, no firmware or hardware changes necessary.

author: mwb1100
author_rank: Frequent Contributor
timestamp: January 12, 2025, 05:53:20 pm
content: Quote from: Kean on January 12, 2025, 10:39:24 amIt's possible those changes made it incompatible with ataradov's software/firmware. This is a comment left by a buyer:QuoteIt would be interesting to know if you have a different experience.

author: ataradov
author_rank: Super Contributor
timestamp: January 12, 2025, 06:22:32 pm
content: It would be interesting to see what exactly is wrong. It may be some assembly issue. And I see a lot of user error with this project too.I don't think it is outright incompatible, but slower speed grade FPGA and removing a lot of decoupling from the cypress IC may be contributing to the issue. I have no idea how much decoupling it really needs. I've seen logic analyzers running with just a couple caps.

author: Kean
author_rank: Unknown
timestamp: January 12, 2025, 09:26:17 pm
content: Quote from: mwb1100 on January 12, 2025, 05:53:20 pmOh, thanks for pointing that out. Of course it hides the one negative review by default... but there are still 4 positive reviews.I will try to test it out later this week. I am a bit behind on some projects right now.Quote from: ataradov on January 12, 2025, 06:22:32 pmI haven't done a direct comparison against your BOM, but a rough count of capacitors doesn't show a significant reduction between the pics in those two listings. Moving the caps to the top layer may not be ideal though.And based on the photos the FPGAs in those listings they seem to be the same speed rating (4) on both boards, only in different temperature grades.

author: ataradov
author_rank: Super Contributor
timestamp: January 12, 2025, 09:56:58 pm
content: The one I linked has speed grade 6 both in the pictures and on the actual boards. At least for now. Given that it is an overkill, I assume they just put whatever they had in stock. But they also advertise that in the listing, so when advertisement goes away, I guess it would be a sign that they changed things.

author: Kean
author_rank: Unknown
timestamp: January 12, 2025, 10:23:26 pm
content: Quote from: ataradov on January 12, 2025, 09:56:58 pmI see now that it is 6 in the first photo (which I didn't check). All the other photos on that listing have speed grade 4.But I just noticed that note specifying that they are using speed grade 6, so I see why you pointed to that listing - and that I need to pay more attentionMaybe I'll buy one of their PCBs and swap it into the enclosure I have, but I suspect that may require some milling of the case to avoid damage to some of the caps close to the edge.I'll mention this to my brother as I think he also bought the same one.Thanks!

author: Kean
author_rank: Unknown
timestamp: January 15, 2025, 07:07:03 am
content: OK, I ran some tests today with the PCB that has the speed grade 4 FPGA. I was not sure what to expect if it isn't working right.I was able to use the --test command line option and get about 41-42MB/s. I then did some captures with an FTDI serial interface (full speed), and as best I can tell it is losing data.I will put in an order for one of the PCBs with speed grade 6 part and do some comparisons when it arrives.Thanks to mwb1100 & ataradov for the info.

author: ataradov
author_rank: Super Contributor
timestamp: January 15, 2025, 07:28:33 am
content: Can you share some logs? I don't expect it to subtly malfunction because of the FPGA speed grade. It would likely fail entirely. The design relies on the uninterrupted stream if one byte gets lost, the whole stream will de-synchronize. If you consistently see any frames at all, then it is likely working and any loss would be due to different reasons. The frame loss may happen on the USB PHY side, but again, FPGA grade would not matter here.The difference is not huge. The design is supposed to work at 60 MHz and in grade 4 FPGA it gets to 56 MHz or something like this. This is realistically within the margins especially at room temp.And if speed test does not fail and runs for a long time, it means that FPGA-MCU interface is stable. The test uses pseudo-random sequence generated on the FPGA side and checked on the PC. It is not just a lot of dummy data, it is actually checked for correctness.42 MB/s is a bit slow, but should not matter for FS. This is likely because of the internal motherboard hub. There must be a port with direct connection to the root hub that would get better speed.

author: parawizard
author_rank: Regular Contributor
timestamp: January 15, 2025, 08:00:20 am
content: What makes you think data is missing?I ended up picking up an used Total Phase Beagle 480 as well. I haven't received either yet. The Beagle was less than half of new retail price and is still 20x+ more expensive

author: Kean
author_rank: Unknown
timestamp: January 15, 2025, 09:14:47 am
content: Quote from: ataradov on January 15, 2025, 07:28:33 amI didn't save any captures unfortunately - they didn't seem too useful. I need to head home now (it is getting late here), but will try again in the next day or two.QuoteOK that is good to know. I wasn't sure if it would be slightly unstable at the packet level, or drop out completely.I saw some weird output in Wireshark, but wasn't sure if it was expected or not just because of what I was doing.e.g. if I set it to full speed and started a capture with no device plugged in I was getting a bunch of phy errors - but once plugged in I saw the negotiation and device descriptor queries.What made me suspect partial data loss is that I typed "Hello" into putty and only data the data packets for "H", "l", and "o" characters.Honestly I don't know USB packet structures very well, so I usually just make assumptions about what looks good or not.I have an STM32 based GPS tracker project I want to get back to where USB never worked. It has been a number of years, but I was pretty sure that was a MikroElectronica compiler/library issue.QuoteI was wondering how well the test mode actually tested it. I read the notes on github, but it didn't give a lot of detail and I didn't delve into the code.I had it plugged into a USB3 hub on my desk that comes off my USB-C docking station when I tested it earlier.While typing this I had it plugged into the USB port on the side of my laptop, and I was getting a pretty stable 46-48 MB/s for more than 15 minutes.Quote from: parawizard on January 15, 2025, 08:00:20 amAs mentioned above, I was just capturing the packets to FTDI USB serial while I typed Hello and could not see all those characters in data packets.

author: ataradov
author_rank: Super Contributor
timestamp: January 15, 2025, 02:33:18 pm
content: Quote from: Kean on January 15, 2025, 09:14:47 amThis happens sometimes. PHY picks up random noise on the floating lines and interprets it as packets. I don't try to suppress it, I just show everything that PHY shows.Quote from: Kean on January 15, 2025, 09:14:47 amAt full speed I would have expected it to capture everything, but I would need to see the logs to confirm.Quote from: Kean on January 15, 2025, 09:14:47 amIn that case the speed drop is normal, hubs will do that.

author: parawizard
author_rank: Regular Contributor
timestamp: January 20, 2025, 01:58:28 am
content: The peripheral I am working on is having difficulty connecting through the analyzer. Haven't checked out what is being reported to wireshark yet. I switched out to the best USB cables I have and it works half the time now. Note it likely has a large impedance mismatch. Didn't seem to work at all with the included cables. It's a high-speed device with a captive cable. Will reply again after I've looked at it more carefully

author: ataradov
author_rank: Super Contributor
timestamp: January 20, 2025, 02:21:54 am
content: Included cables are complete trash. Any thin and flexible cable are not likely to work. Generally USB3 cables work best. USB3 part does not do anything, but they have not bee optimized to death.And while things seem to work while USB sniffer itself is not powered, I would not use it like that, since this may cause additional issues.Ans as always, it is better to connect to the root hub ports for both the target and the sniffer itself. Any hubs in a path may cause issues.