On May 26, 2006, at 5:33 PM, Martin Peach wrote:
Hans-Christoph Steiner wrote:
I just realized the answer to my question about getting positive- only voltages from the sound card. The DC filters will probably
remove the DC offset, therefore, the output voltage on a PWM
signal will also be centered again on 0, and therefore swing from
negative to positive. I do remember getting some very low
frequencies out of a computer when testing speakers. But I
haven't actually tested this [pwm~] object for electronics. But
it would be nice to have a very well implemented [pwm~], so its
great that this discussion happened. I did use the [pwm] object with a MIDI-controlled relay box,
worked quite well at 30-60Hz on a biggish DC motor.But that sounds like you're sending MIDI messages at a rate
determined by the [pwm], so bandwidth is limited by MIDI to ~1kHz.
Better to program your relay box to do pwm with the pulse width
controlled by MIDI, instead of using MIDI just to turn the motor on
and off.
Sometimes you make do with what you have in the amount of time you
have. I make no claims that this was a great solution. But it does
work.
.hc
"Terrorism is not an enemy. It cannot be defeated. It's a tactic.
It's about as sensible to say we declare war on night attacks and
expect we're going to win that war. We're not going to win the war
on terrorism."
- retired U.S. Army general,
William Odom