Probably the thing will read quieter if the pots are lower resistance.
The data sheet for the atmega microcontroller used in the arduino says
hat the impedance of the analog source should be less than 10kOhm. Also
putting a .1uF capacitor from the analog pin to ground will smooth out
glitchy noise. (And averaging a few values in software helps too.)
The arduino can send its data as MIDI by using two 220 Ohm resistors
(one from 5V to MIDI pin 4, the other from TX to MIDI pin 5, ground to
pin 3) and a baud rate of 31250. That can eliminate noise caused by the
USB connection, but you have to program the MIDI messages yourself
instead of using pduino, as well as powering the arduino from a battery
(quiet) or AC adapter (noisy).
I have built a MIDI pedal that uses an optical sensor to detect the
pedal position. It is much quieter than a potentiometer.
Martin
On 2011-04-10 10:56, Pedro Lopes wrote:
You can filter out some noise if that happens. I have done several
arduino projects (namely public installations or sculptures with
sensors), one thing I learned is that you can always filter the (some)
noise, by ignoring some values and so forth.
Another fun aspect is that in public installations whenever I connected
the arduino to the AC power outlets (instead of battery) the noise was
much higher. (which makes sense, since AC powers of houses, steet, etc..
are actually noisy (have you ever noticed that AC induces noise on most
laptop on-board sound-cards - due to ground loop and so forth) )
>use i wanted to use a pot to control a delay length (you can hear
gliches if the delay length jumps from one value to another rapidly).
But don't panic about it, its workable. You can defined thresholds, and
if it varies withing a certain range you will not consider as the pot
has moved, if you do not have noise: even better. But electricity is not
perfect, components are definitely not perfect either :)
Best,
Pedro
On Sun, Apr 10, 2011 at 3:50 PM, Pierre Massat <pimas...@gmail.com
<mailto:pimas...@gmail.com>> wrote:
uctuate a little"? This could be anoying if they fluctuate too much,
because i wanted to use a pot to control a delay length (you can
hear gliches if the delay length jumps from one value to another
rapidly).
--
Pedro Lopes (MSc)
contact: pedro.lo...@ist.utl.pt <mailto:pedro.lo...@ist.utl.pt>
website: http://web.ist.utl.pt/Pedro.Lopes /
http://pedrolopesresearch.wordpress.com/ | http://twitter.com/plopesresearch
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