[Matt] was looking into some software that allows him to use his audio card as a means to control analog audio devices. After seeing how it worked, he got an idea to try to do the opposite. He is sending a signal into his audio input, and piping it to a pice of MIDI software. The input he has chose is a foot switch. To create the signal, he simply needed to supply voltage while the switch was depressed. You can see above that he used a battery and a simple contact switch to send the signal. He then piped it to a virtual MIDI port using Maple Virtual MIDI Cable. Unfortunately, this isn’t suitable for knobs, but that may be next on his list.
How is this passive?
Hmm… that is a good question – passive usually means that a voltage isn’t sent from a device.
@hogiewan:
Author here, I described the switch as “passive” because that’s how it started out and the hardware was pretty much trivial. But you’re right, I should have just described it as a “Simple MIDI footswitch” or something. Mea culpa.
I’m suprised there isn’t even a resistor in series…. Current limiting devices are your Friend!
haha, right on jay. And always isolate mains power. You wouldn’t want to let the magic smoke out.
Honestly this is a pretty lame hack. 2 x 16bit 44khz for a binary signal activated by his foot. That’s a lot of redundant data and processing. It would be easier to pull apart an old mouse or keyboard and use glovepie.
I’m at a total loss with midi. been trying to set up for glovepie and can’t figure it out. Maybe the OP would be willing to help. Then maybe I could build this also and put it to good use.
This would have been easier with the lpt port, yes your pc without one still has one, look for the header inside.
I’m quite a noob so I’m missing the point of this.
what is this supposed to do? control some software application function via an analog switch connected to the midi port? emulate a keystroke?
@anonymous: you’re not the only one. So, what does it actually do?
Orrr… You could just go the sysex route. Really not sure how this hack is totally useful. Although releasing a fake audio program with a fake soundbank and then having a website with a midi file that is linked to that app and let the drive-by malware begin. Anyhoo, keep plugging away.
I’m looking at the miduino card by tom scarff http://tomscarff.110mb.co/products_prices.htmmiduino
to get input that can start/pause/continue a song using the song position indicator. we’ve bumped into a problem with not having an external clock in external sync mode. this sort of relates to the foot pedal. Any suggestions? I need to have a bunch of these up and running before halloween!