6 May
2005
6 May
'05
3:50 p.m.
Paul Coccoli wrote:
Hmm...so if DTR is set to +13V (0) and RTS is set to
-13V (1) for
example, then I can use switches connected to CD, DSR, and CTS so that
each pin can read 0 or 1. Is that correct?
That sounds correct.
Where do the resistors
go? Between DTR and the 3 switches and RTS and the 3 switches?
I'd be inclined to put series resistance onto each DB9 pin you utilise.
In the event of a damaged cable this would limit any short circuit
currents to levels which shouldn't cause irreparable harm.
If it were my motherboard/serial-port, I'd find the highest value
resistance that reliably works between DTR and an input (hint: use a
variable resistor and measure it's value when disconnected): I'd then
use fixed resistors of at most half that value.
Thanks for the suggestions, Rob.
You're welcome. I look forward to seeing a footswitch-virmidi app soon :)
Rob