Re: USB module for monitoring multiple on/off switches

[Uniden <uniden@xxxxxxxxxx>]

In article <4ae32b95.4247718@xxxxxxxxxxxxxxxxxx>,
shb*NO*SPAM*@comporium.net says...
> On Fri, 23 Oct 2009 17:24:43 -0500, gordon@xxxxxxxxxxxxxxxxx
> (Gordon Burditt) wrote:
>
> >>Why would somebody get a bunch of paraphenalia to hang on a USB port so they
> >>can slow the signal down?
> >
> >How many feet can a USB cable be run before it ceases working even
> >at the slowest USB speed?  If I need to run the cable to the front
> >door, back door, refrigerator, freezer, garage doors, every window,
> >some motion sensors, a couple of smoke alarms, and a keypad, that's
> >a lot of cable.  On the other hand, polling each sensor 5 times a
> >second is probably way overkill.
> >
> >Four USB-to-parallel-port devices, with the parallel-port devices
> >(with data and control lines, you may be able to sense 10 contact
> >closures each) spread around the house, might be sufficient.
> >
> Sorry, but you can't use those devices the way you mention. They
> only work with print drivers.

This type of device works. It allows for reading and controlling 16
TTL/CMOS lines:

USBmicro U401/U421 found at
http://www.circuitgizmos.com/products/cgu421/cgu421.shtml
And the drivers are a part of the OS.