Re: "Capture Aborted! Device Not Found!" after update

A cheap logic analyzer. Get one for $50, including worldwide shipping. A collaboration between the Gadget Factory and Dangerous Prototypes.

Re: "Capture Aborted! Device Not Found!" after update

Postby jawi » Tue Jan 18, 2011 3:18 am

frank26080115 wrote:I just wondered about the CDC stuff because I have a genuine Saleae Logic, and a Saleae Logic clone from ITead Studio called Mini Logic (which also works as an USBee and Altera USB Blaster). ITead Studio was able to reverse engineer the Saleae Logic and USBee so that he can make a clone that is compatible with their software (which wasn't hard, I think the Cypress chip is basically a USB FIFO bridge in all three cases, configured via EEPROM, the clone just had several EEPROM settings to load). I do have a software USB packet analyzer. I would like to see if it is possible to achieve the same thing with the OLS.

Great work with the open source stuff, but the USBee client software can analyze USB packets at a low level, which I hold in high regard


I've been playing with the idea to write a USB decoder tool, however, with the current OLS, sampling USB is only possible for USB1.1. An alternative could be to simply use the USB-protocol stack of the PIC controller directly, and let it "sniff" the USB signals. This way we could support both USB1.1 and USB2. I believe this is also how the USBee hardware does it...

Edit: an alternative would be to use a dedicated USB-sniffer, such as the (very promising!) OpenVizsla project.
Last edited by jawi on Tue Jan 18, 2011 3:20 am, edited 1 time in total.
when good software is not an alternative...
User avatar
jawi
Developer
Developer
 
Posts: 596
Joined: Thu May 27, 2010 2:54 am
Location: The Netherlands

Re: "Capture Aborted! Device Not Found!" after update

Postby rsdio » Tue Jan 18, 2011 5:46 am

frank26080115 wrote:ITead Studio was able to reverse engineer the Saleae Logic and USBee so that he can make a clone that is compatible with their software (which wasn't hard, I think the Cypress chip is basically a USB FIFO bridge in all three cases, configured via EEPROM, the clone just had several EEPROM settings to load). I do have a software USB packet analyzer. I would like to see if it is possible to achieve the same thing with the OLS.
I would not recommend this.  Saleae logic needs a real-time protocol yet is not designed to take advantage of the appropriate USB features for real-time.  As a result, since Saleae logic does not negotiate for guaranteed bandwidth, many LA captures fail.  This makes the product really annoying, because the failed capture is always the one where you lose the data you need.  The limited 24 MHz sampling rate is exacerbated by the fact that failures become more frequent at the highest rates.  Some people have pointed out that Bulk transfers have error correction and retransmission, while Isochronous transfers do not.  However, despite getting many other things wrong, the designers of USB understood that it is pointless to have the option of retransmission when you're already using the maximum bandwidth, or even a smaller but fixed bandwidth.  Isochronous still allows error detection.

Anyway, I don't think it would be a good idea to try to turn the OLS into a Saleae logic emulator, because the performance would really suffer.  About the only thing to be gained from this would be access to the gorgeous front end software.  However, front ends are a dime a dozen, and it's probably better to spend time writing a nice front end for OLS that supports sample rates above 24 MHz and channel counts beyond 8 inputs, instead of trying to reverse engineer some kind of compatibility.  Besides, I don't think Joe would appreciate anyone attempting to use his front end for another product.  I sure hope Itead had permission...

Don't get me wrong: The Saleae logic is a beautiful piece of hardware and software.  I'd love to have a tiny, milled aluminum enclosure for every Dangerous Gadget I own.  I bought extra clips from Saleae for use with my OLS.  I think the front end software is the nicest thing I've seen in a long time.  But with all those great features, the Saleae logic still needs some serious work in the protocol department, because the way it uses USB is not appropriate.  Emulating this part of the equation would be a really bad choice for the OLS.
User avatar
rsdio
Developer
Developer
 
Posts: 1407
Joined: Sun Feb 28, 2010 10:53 pm
Location: Seattle

Re:

Postby mrjoda » Sat Nov 12, 2016 10:02 am

hi guys, i have same problem as author of topick and this dude https://www.youtube.com/watch?v=b4142knk5pk

after i bought it, i tried it and it wont work so i flashed new firmware, it tooks few hours because were problems with PIC flash. I flashed new Demon FW (now i cant flash older FW (errors)).

it doesnt work with any SW software (official, Jawis or PulseView) and i am really pissed of because i spend 67€ for not working crap.


can you help me please ?

thanks
Attachments
Screenshot_1.jpg
flash.jpg
mrjoda
Newbie
Newbie
 
Posts: 39
Joined: Sun Mar 01, 2015 11:08 am

Previous

Return to Open Bench Logic Sniffer

cron