[PD] gpio on the raspberry pi from within pd ?

J Oliver jaime.oliver2 at gmail.com
Wed Jul 24 11:13:10 CEST 2013

Hi Dan, 

I am Cc'ing the list, which is really your best resource. I haven't output variable voltages from the pi, but I am sure a lot of people have experience with this...



On Jul 24, 2013, at 4:39 AM, Dan Nigrin wrote:

> Hi Jaime,
> Saw this post of yours from back in April re: GPIO access from within Pd on the Raspberry Pi:
> http://lists.puredata.info/pipermail/pd-list/2013-04/102172.html 
> I'm a total Pi newbie – I don't even own one yet.  I'm considering a project with it though, where I would like to use Pd to generate some audio, and to output it to another device (a Mutable Instruments Shruthi synth filter board).  However, I also need to generate control voltages that need to get sent to the filter board, to control its various parameters (e.g. cutoff, resonance, etc...).  I also need to send +5v and ground to the filter board.
> So from your post, it seems quite straightforward to be able to access the GPIO pins from within Pd.  But I need to be able to create variable voltages (between 0 and 5v) on those pins.  In the post above, you mentioned that you send a float to the gpio object to write a value to the pin - would sending a 0.5 for example give me 2.5v on the pin?  Or is it only on/off (0 or 5v)?   If the former, I'm all set!  If the latter, I'll need to figure out how to simulate a reduced voltage at the pin (likely using PWM or something – but I'm not really sure how I would do that…)
> Any help greatly appreciated!
> Best,
> Dan
> --
> Dan Nigrin / Defective Records / http://defectiverecords.com 
> CycliC, M185 & Klee Sequencers / MC-4 & MC-202 Hack / Audio Plugin Player / General MIDI Player / Major Malfunction
> Jack OS X / http://jackosx.com 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-list/attachments/20130724/be7a1c01/attachment.htm>

More information about the Pd-list mailing list