[PD] problem with arduino digital ins - Pduino-0.5beta8 / Firmata 2.1

Roman Haefeli reduzierer at yahoo.de
Wed Jun 30 15:19:55 CEST 2010


On Wed, 2010-06-30 at 14:12 +0200, Ingo Scherzinger wrote:
> Hi Roman,
> 
> this solution is working also. So in this case it's not really necessary to
> change the firmata itself. Anyway, I would prefer to have this behaviour as
> the default behaviour, i.e. included in firmata. At least all of this this
> should be documented.

Actually, it is here: 
http://www.arduino.cc/en/Tutorial/DigitalPins

It's not firmata exposing this functionality, but the arduino. So I
think it's correct that Firmata handles it transparently, so that from
Pd you are still able to decide yourself, whether you actually want that
pull-up resistor or not. 

Enabling it per default is _not_ a good idea, since there are many
applications, where you deliberately want the pull-up resistor not to be
enabled. Imagine a sensor with a very high impedance (for instance, an
LDR in series with a fixed 1 MOhm resistor), with the pull-up resistor
activated the input would always be HIGH, because the internal resistor
would brutishly pull the voltage up.

Roman








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