Re: poor man's IO?

["E. Lee Dickinson" <lee@xxxxxxxxxxxxxxxxxxxxx>]

"wkearney99" <wkearney99@xxxxxxxxxxx> wrote in message
news:3tSdnc1BCNmzs3jfRVn-iQ@xxxxxxxxxxxxxxxx
> I'm aware of that one can use a gamepad or joystick to provide a "poor
> man's
> I/O interface" for input signals.  But how about output relay closures?
> What's available with a USB interface that would lend itself to being used
> for controlling switches, presumably with external relays?  I'm thinking
> of
> using something like this for handling stuff like the 12v signalling
> question posed in another thread.  I'm not insisting on taking the cheap
> way
> out but would prefer to find something in the sub-$50 range.  Perhaps with
> at least 8 outputs?

There's a parallel port relay board available at www.electronickits.com - 8
relays. They also have a serial version at around $60, iirc.

The parallel port one is actually very simple, and you can find plans for an
equivalent all over the 'net, and in a number of books. Basically, an
optoisolator, transistor, and a relay.