[PD] Pduino output mode and I/O numbering differences

[David Merrill]

Georg Holzmann wrote:
> Hallo!
>
>> I'm playing around with the latest arduino object for pd, and it 
>> seems that there is a disconnect between the numbering for port I/O 
>> data-direction, and setting the value of a pin. I'm using the 
>> arduino-test.pd patch, as well as the [pd DIGITAL-OUTPUT] behavior 
>> pulled from the arduino help patch.
> I don't really understand this - you mean you can set input/output 
> mode for pin 13 with toggle 6 (and please try it in the help-patch) ?
Hi Georg,

What I'm confused about is that usually in microcontroller programming, 
there is a symmetry between setting the data direction of a pin (i.e. 
input or output), and setting/clearing a bit on that pin. For instance, 
in AVR C, if I want to assert a HIGH voltage on pin D0, I would write:

DDRD = 0x01;    // set data direction for pin 0, port D to output
PORTD |= 0x01; // set value of pin 0, port D to HIGH

..so the same value is used both to set the data direction and set the 
bit on the pin. That's what I'm confused about the example patch for 
arduino - where the same number does not get passed for data direction 
as for pin setting (see my previous attached .jpg). It's probably 
because I didn't dig into the example to see why this mapping is 
different - but since arduino/pduino is supposed to be good for physical 
computing students who know little about the nitty-gritty details of 
hardware/software integration, it should be as straightforward as possible.

The patch in the .jpg that I sent is the arduino-test.pd, with the "I/O 
the individual pins" section taken from arduino-help.pd. I'm pretty sure 
I have the latest pduino firmware - I downloaded from HCS's website 
directly yesterday.
thanks,
-David
>
>> p.s. also, clicking the "pulse all outputs" box in arduino-test.pd 
>> crashes PD after a few seconds - I suspect due to a comport problem.. 
> Do you have the latest firmware and have you tried the PWN-OUT of the 
> help patch?
>
> LG
> Georg


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MIT Media Lab
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