[PD] Arduino, any feedback to help me choose the model?

[Pierre Massat]

Hi,
I just ordered a Uno, i think it will suffice.

Martin, I'd like to replace my pot with an optical sensor if it's quieter.
Only i've never used one. How does it work? How do i put this in the pedal?

Looks like i'm not nearly through asking questions about arduino...

Pierre

2011/4/10 Martin Peach <martin.peach at sympatico.ca>

> 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 <pimassat at gmail.com
>> <mailto:pimassat at 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.lopes at ist.utl.pt <mailto:pedro.lopes at ist.utl.pt>
>>
>> website: http://web.ist.utl.pt/Pedro.Lopes /
>> http://pedrolopesresearch.wordpress.com/ |
>> http://twitter.com/plopesresearch
>>
>>
>>
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