On Jun 17, 2007, at 1:10 PM, Roman Haefeli wrote:
On Sun, 2007-06-17 at 12:41 -0400, Hans-Christoph Steiner wrote:
That's Roman of netpd fame (you can see netpd on the screen). I forgot whether Pduino was used for that or not. I would like to know. A student here at Poly in Brooklyn used Maxduino (the Max/MSP port by Marius Schebella) but had a lot of trouble with timing. I would like to see whether arduino USB can do tight timing like in that video.
yup, i used the pduino firmware, though not the arduino
abstraction. for my purpose - i wanted to work with a timegrid and a stepsequencer,
where sometimes more than solenoid were triggered at the same time - i
did not use the [arduino] abstraction in order to send only message (for
example '24' to trigger solenoid 4 and 5) instead of two messages ('16' and '8').
Seems like Pduino should have a message to send the whole button
array at once, since that's what's going on underneath. Something
like [digitalPort 29730(, where 29730 would be the bitmask of the
digital pins. Or it could directly mirror the underlying firmata
message like this: [digitalPorts 116 42( with two sets of 7-bits.
it worked quite well, but there is still room for improvements (i mean not for the pduino-project, but when arduino is used to trigger solenoids). it turned out that the length of the 'on' period is very sensible. a bit of jitter in that period causes sometimes the
solenoids to not reach the object or to hit it too strongly. since pd controls both, the on and the off time, this period is not very constant.
when i find time to learn the arduino language, i might write my own
firmware, where i can send the period as a second value, so that the arduino itself controls the timing and not pd.
I don't think that the timing problem is related to Pd but rather the
USB-serial drivers. Writing your own firmware to trigger events will
work if you send the timing, which would then be handled by the
arduino, therefore eliminating the USB-serial issue.
Instead, I think we'd all be better off if we can work together to
get Pduino working for this kind of application. This is exactly the
kind of stuff I had in mind when I wrote Pduino. I am open to
suggestions and patches.
.hc
roman
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