6 May
2005
6 May
'05
4:59 a.m.
Paul Coccoli wrote:
<snip>
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.
Hello Paul
The answer is - it depends a little on your hardware :)
A few points;
1. RS232 is nominally a +/- 13v (ish) system - you don't want to ground
anything.
2. It's an I/O port, and should be safe against short circuits, but I'd
recommend using at least 1K series resistance when you're poking around
there :)
3. The RS232 inputs should have pull-ups/downs to bring them to valid
levels when disconnected.
In summary - with 99% of normal sane hardware, it should work (but I'd
recommend the precaution of a 1K resistor).
Best of luck
Rob