I suppose you're right about the different types of controllers being attached to the arduino. It's definitely better to keep the pullup resistors off as default!
I think it just needs an extra line on the help patch so people would know about this "feature" and how to use it. Ingo > Von: Martin Peach [mailto:martin.pe...@sympatico.ca] > Roman Haefeli wrote: > > 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 > > And shining through that is the actual microcontroller. It's useful to > read the data sheet to see what is possible: > http://www.atmel.com/dyn/resources/prod_documents/doc8271.pdf > > > 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. > > Or if the pin was connected to a relay or something. This is why most of > the pins default to high-impedance input after a reset. > > Martin _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
