[PD] arduino+solenoid concert

Hans-Christoph Steiner hans at eds.org
Sun Jun 17 20:36:47 CEST 2007


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
>
>
>
>
> 		
> ___________________________________________________________
> Telefonate ohne weitere Kosten vom PC zum PC: http:// 
> messenger.yahoo.de



------------------------------------------------------------------------ 
----

Man has survived hitherto because he was too ignorant to know how to  
realize his wishes.  Now that he can realize them, he must either  
change them, or perish.    -William Carlos Williams






More information about the Pd-list mailing list