USB Snoopy

What is it?

USB Snoopy is a little software tool for Windows 98 to watch traffic on the USB bus. It can be used for a multitude of purposes, including debugging your own code, and eaves-dropping on devices' traffic.

On this page, you can find the very first version - warning: it is largely unfinished. We are working on a much improved version, but due to the big demand out there for a tool like this (not everyone can afford one of those wonderful toys from CATC - a cheaper alternative might be available from Catalyst Enterprises (I have not tried this one, but it's supposed to be more powerful CATC, right, Joe? ;-)), we decided to put it up for public consumption.

How does it work?

USB Snoopy is currently made up of three pieces:

Where can I get it?

Get the current package (version 0.12), source and binaries, here (341KB)
Get the older package (version 0.1), source and binaries, here (342KB)


The format output by USB Snoopy is strongly based on the way Windows handles USB transfer requests. It tries to be somewhat smart about omitting data that is irrelevant. For example, if you read from a device, you only need to print the buffer's contents after the read returns. There are a number of things that can go wrong, or that might confuse you. Here are a few hints:

Revision History

Version 0.12 (05/11/2000):

Version 0.1 (04/07/2000):

Todo (whenever I get some time...)


If you are using Linux USB and want to play back a log that you captured with USB Snoopy (Version 0.1), you might be interested in John's usb-robot, a nifty tool which takes a USB Snoopy log and plays back the captured data to a device.


...go out to everyone who downloaded the package, tried it, lived through a number of crashes and got back with some comments or concrete suggestions/bugs. If you want me to add your name here, let me know.

Other stuff...

As always, no liability is assumed for anything. If the filter burns down your house, puts you out of business or out of your mind or anything else, we're not responsible. It's not meant for any illegal purpose. Sorry - had to say that (CYA).

Who did this? did the UI, did the filter. Drop us a note if you like it or hate it, or if you have any good ideas what could be done with it.

This page sucks. Heck, we're software people, not designers! :-)

and the counter is... :-)