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USB Development Tools for Embedded Devices?
engywook asks: "I am thinking about putting a USB interface onto a real-time (home-brew kernel) embedded device, (naturally) with the intent that it talk to another device. I am thinking that it would be very useful to be able to monitor the USB traffic between my device and the other device, and between that other device and (say) a PC that already knows how to talk to it. Looking around, it seems that this capability is available, but at prices in the US$10K and up realm, which is a lot more than I can afford. I am looking for pointers to tools that would accomplish this for much less money. Any ideas would be appreciated! Thanks!"
Last month's Linux Journal has an article titled "Snooping the USB Data Stream", where the author talks about exactly what you want. He talks about using Linux to monitor the data, but you can still use this method to monitor Windows talking to your device by running Windows in VMware.
I bought a Cypress USB kit a few years ago, it's quite cool. Is that company still in business? Their website seems to be gone.
True warriors use the Klingon Google
there are tons out there, cheap. ARM, even
that, and the linux kernel, is all you need to debug USB.
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
your using a custom kernel so
s id=7582
look at netbsd USB stack and see howto put that into your src
you can dump out the usb traffic under netbsd look at the src
if you want to reverse engineer a windows driver you can use VMware on linux and dump the traffic
http://www.linuxjournal.com/article.php?
or
insert a windows driver (that dumps usb traffic) and look at the dumps but this could taint the results see http://usbsnoop.sourceforge.net/
or
buy a hardware that sits inbetween the cables for $1000 see http://www.usbdeveloper.com/USBViewer/usbview.htm
really I would look at http://www.fsmlabs.com/ as you can run real time tasks and use the linux drivers for usb because that part sure as hell is not going to be real time...
it you have failed to do ANY RESEARCH at all
Terrible. F
regards
john jones
Assuming that you're happy with USB1.1 and below, one approach is to use a low-cost FPGA (Altera Cyclones are great for this, and a suitable one is $20).
Zip over to opencores.org, grab the USB 1.x MAC and PHY as a starting point....and you can start to build your own hardware USB sniffer.
The beauty of this approach is that you can do *proper* sniffing type activities such as microsecond time stamping of samples, which gets (*ahem*) tricky doing things in the software domain under Linux or Windows.
If you just want to see a vague picture of the wire, you can stick to operating system level sniffing as others have pointed out.
-psy
Seek out USB Snoop. You can monitor the goings-on between Windows and the USB device's driver. This probably won't replace a hardware USB debugger, but it's a good start.
Your usage description seems to advocate a more node-to-node based relationship between devices on the bus. An interface like firewire seems much better suited to your application than USB (master/slave). Though I suppose it could be considerably more complex to implement?
If you still need a hardware analyzer, this one looks more affordable.
Use one of the FTDI USB tranceivers instead of trying to reinvent the wheel.
http://www.ftdichip.com
They make usb chips with serial interface (drop in replacement for an RS232 transceiver) or an 8-bit parallel interface. Comes with drivers for windows and there are drivers in the kernel already.
Only does up to 12Mbit/s though.
Cheers,
Roger
Do you have any better hostages?
If all you want to do is get your USB device working, I'm not so sure you really need this capability. USB analyzers are primarily useful for testing the device for compliance with USB signal standards. That way, you only have to get your device compliance-tested once.
I've developed a few USB devices, and frankly I haven't needed an analyzer just to get the device to work. If something's happening you don't understand, set breakpoints or toggle some status LEDs to see where you are in the firmware. That, and software-based sniffing for the occasional sanity check, has been all I really needed.
Learn the standard USB device types, and if you try to reverse-engineer a proprietary device, stock up on Advil.
I've seen a lot of USB snoop suggestions, which are a fine solution. But if you don't find that acceptable, I'd suggest looking into a Controller Area Network(CAN) module instead. You can find PC adaptors for this very cheaply, sometimes as little as 20 dollars. It's specifically designed for systems where you know exactly the kind of communications that will go on, and who's more important than who. It's used in a lot of automotive situations, though there's a growing group that doesn't think it's safe enough.
I Browse at +4 Flamebait
Open Source Sysadmin
First, get a copy of USB Complete. This book provides a good reference to the USB interface, and is oriented to hardware design. It also gives a lot of useful advice on picking a USB controller.
Second, visit the Silicon labs web site. They sell a development board for their USB enabled Microcontroller which includes all cables, an assembler, and a bunch of utilities and examples. They also include a development kit for implementing the Windows drivers for your new device.
Finally, there's a utility available on the web called Snoopy which will let you capture USB packets.
It's good to use your head, but not as a battering ram.
And the worms ate into his brain.
I've had success with USB to serial converters. I bought a bunch of them for $12.00 apiece from Belkin, for example. Email me if you want more info.