[linux-audio-user] [OT] DIY serial input devices?

[michael at michaelshiloh.com]

Does your computer have a parallel port? There are tons of examples on
the web of how to do simple digital IO on the parallel port. Even if the
port itself is unidirectional, there are a couple of status lines (busy,
paper out) that can be read.

m


On Thu, 5 May 2005, Paul Coccoli wrote:

> I've been thinking about a way to interface a footswitch to my
> computer for triggering things like sooperlooper and fweelin.  I've
> got a sustain pedal for my MIDI controller on the way, but it got me
> thinking.  I've got a perfectly good serial port on the back of my
> computer, doing nothing.  I'd like to put it to work, but my hardware
> skillz are, well, lacking.
>
> I've figured out this much: you can wire a simple loopback by
> connecting DTR to DCD and DSR and connecting RTS to CTS.  What if you
> insert a switch between these?  E.g. connect RTS to the sleeve pin of
> a female 1/4" TS jack and CTS to the tip pin.  Could you then plug in
> a sustain pedal?
>
> I've seen software that monitors the state of the pins on the serial
> port, so I'm not worried about that part.  I'm just not sure if the
> hardware would work.  Like when the switch is open, do you connect CTS
> to ground?  I don't know enough about this stuff.
>
> Any hardware hackers out there?  Am I crazy?  I suspect there's more
> to it than what I've said here.  Could I wire up a TRS jack and a TS
> jack and plug in my amp footswitch (2 switches) and a sustain pedal?
>
>