Can't get DSPro or generic USB logic analyzers working today ?? - Page 1
Forum section: electronics / general

author: MathWizard
author_rank: Super Contributor
timestamp: April 18, 2025, 10:19:43 pm
content: I'm probing something on my stereo, but neither of my LA's want to work today. I checked the signals are indeed there, 0-5V logic, with a scope. And I'm using a new USB 2 cable I bought just for the LA.For the generic USB LA, I'm using Pulseview, and it was working all winter. In the past, I ran Zadig and installed the WinUSB driver WinUSB (v6.1.7600.16385), and in windows10 DeviceManager, it shows up as 'fx2lafw' device, and says the driver is libwdi version 6.1.7600.16385. I tried to reinstall them today, but it just timed-out, as I think it's up-to date.In Pulseview, pressing run works, but it shows no data, at any speed. All winter it was recognized as a Saleae Logic, but today none of those saved settings work. And when I try changing device, and click the fx2lafw, or ftdi-la, or any other driver, and then scan for devices, nothing shows up. Except once today it did show up as a Saleae, but still when pressing run, it runs, but shows no data.Windows and USB, always seem to be a hassle. I could try uninstalling/reinstalling it all.Before trying that LA, I tried my new DreamSource U3pro32 for the 1st time today. I installed it's software, and connecting to a USB3 port, with the USB2 cable, it warns me to use a USB3 port. But IDK if it tests what port/cable I'm using. The self-test passes no problem, and shows data on all channels.But so far looking at the stereo, it only seemed to detect a couple of 3us pulse signals, while all the slower/longer data and clock signals were missing. I've tried different simple triggers, from different channels, and no luck.Now I did only use 2 common GND wires, the 'fly-wires' as they call them are grouped as 4 signal/gnd pairs per wire bundle. I'm using 8 pairs, but I'm only using 2 of the 8 GND wires. My signals are well under 5MHz, so the pdf says that should be ok.Any idea's or help would be appreciated

author: mwb1100
author_rank: Frequent Contributor
timestamp: April 19, 2025, 01:06:03 am
content: Just in the interest of basic troubleshooting I'd suggest the following:- troubleshoot one analyzer or the other; if you try to troubleshoot both in one discussion thread it'll get hopelessly confusing. Once you get one working you can move on to troubleshoot the other one if you want.- troubleshoot on a known, regular signal first; something like the 1kHz probe compensation signal on the oscilloscope would probably be good to use. That way everyone helping out will know exactly what should show up and if they want they can replicate what you're doing (or should be doing) on their systems, assuming they have the same analyzer that you do- tell us exactly what you are working with - model, USB VID/PID, OS, OS version, driver version, software versions; consider posting configuration files if that makes sense- when you get the software to display something, a screenshot would be more useful than describing what you see. If the information you want to post is text, copy/paste it asTEXT, not as a screenshot.And you are right that Windows USB support for non-general consumer devices can be a nightmare. It's not a bad idea to uninstall/reinstall the drivers - rebooting between each step where it might make sense to reboot.Another approach you might take is to run Pulseview on a Linux VM. Current versions of VMWare and VirtualBox are free - even for commercial use - and include very good support for connecting USB devices to the guest VM. USB devices on Linux are handled much more sanely than on Windows (the one exception is often having to muck around with /etc/udev/rules.d/ config files to provide sensible permissions to access the device as a non-root user).And if you have a USB 3 based analyzer, I think you should connect it using a USB 3 port and cable - just remove that one possible source of headaches from your troubleshooting. (and if you use a VM, make sure it is configured to support USB 3 - I don't remember what they default to). And use a port directly on the computer instead of a hub if possible.

author: Ian.M
author_rank: Super Contributor
timestamp: April 19, 2025, 02:01:16 am
content: Salae Logic 8 clone (fx2lafw) analysers can be problematic if the USB cable isn't good quality and in good condition. I have seen what I believe to be the same issue - Pulseview appears to run OK and you can connect to device using the fx2lafw driver and USB interface and select the resulting 'Salae Logic' device, but when you click , it returns immediately and doesn't capture any data. IIRC there were some errors in Pulseview's log, which can be found in its Settings dialog (crossed screwdriver and wrench icon). Changing the USB cable to a thick known good one (purchased with a PICkit 2, and previously only used once), connected to a host port, not a hub resolved the issue.

author: MathWizard
author_rank: Super Contributor
timestamp: April 19, 2025, 03:18:31 am
content: AAARRRGH another false alarm I guess. Yeah it's the stereo that's not doing what I expected, not the generic LA. And the speaker's aren't hooked up.I saw a constant 5V signal in Pulseview before, but I uninstalled the USB device, cleaned the registry, rebooted, and then reinstalled Zadig and the driver anyways, and it finished.But yeah pushing the volume change and mute buttons, it seems no signals were being sent from the MCU I guess. So I didn't notice the LA probably was working. But when I turned the stereo on/off, the MCU did send some volume and channel IC commands and the LA worked.I replaced 1 of the volume IC's this week, and overall, the volume seems way lower than I remember, and the mute is not stuck on or anything. And the volume on the display changes, with the knob and remote control. And so did the signals, coming from the volume IC's when I had it on the scope the past couple of days. They changed logarithmically. And the output drivers were all working before. But now everything seems way quieter.But then today, I guess the signals just aren't getting sent all the time. I'll have to hook up the scope too. These are all reasons I was programming an ATtiny this winter, to help the stereo's MCU.Ok time to try the U3pro32 again.