Hi there, On 20 Jan 2004, Chris Fowler wrote:
> On Tue, 2004-01-20 at 19:40, Greg KH wrote: > > On Mon, Jan 19, 2004 at 12:39:42PM +0100, [EMAIL PROTECTED] wrote: > > > Somebody knows if it is possible to read the electrical state of the pins in a > > > USB port? > > > > Sure, with a multimeter :) > > But from the OS, no. > > So you're saying there's a chance! Not without extra equipment. There are lots of ways to enable voltage measurements to be made using a PC, but they generally require you to fit a card into the machine. Many such cards exist, some have a large number of input/output ports (for measuring both digital and analogue levels on many points for example, or for recording measurements of voltage levels). Some devices don't need a card fitted to the PC as they can use the existing I/O on the machine. Some can (almost) turn your PC into an oscilloscope. See for example http://www.picotech.com/pc_oscilloscope.html But if you need an oscilloscope then what you need is an oscilloscope. It all very much depends on what you need to do. The PC will never be fast enough to match the performance of the purpose-built instrument with real-time dual trace. Nor without very great expense can it have things like flexible triggering functions, huge sensitivity ranges, high input impedances, high linearity, infinitely variable controls. You'll also need to modify the USB hardware so you can physically gain access to the metal parts which carry the voltages. Not entirely trivial, I'd generally do it by making a small extension box, with a male and female connector wired straight through, so that I didn't have to damage any of the other parts. 73, Ged. ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
