<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div apple-content-edited="true">Hi Dan, </div><div apple-content-edited="true"><br></div><div apple-content-edited="true">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...</div><div apple-content-edited="true"><br></div><div apple-content-edited="true">best,</div><div apple-content-edited="true"><br></div><div apple-content-edited="true">J</div>
<br><div><div>On Jul 24, 2013, at 4:39 AM, Dan Nigrin wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); "><div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">Hi Jaime,</div><div style="font-size: 14px; font-family: Calibri, sans-serif; "><br></div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">Saw this post of yours from back in April re: GPIO access from within Pd on the Raspberry Pi:</div><div style="font-size: 14px; font-family: Calibri, sans-serif; "><br></div><div style="font-size: 14px; font-family: Calibri, sans-serif; "><a href="http://lists.puredata.info/pipermail/pd-list/2013-04/102172.html">http://lists.puredata.info/pipermail/pd-list/2013-04/102172.html</a> </div><div style="font-size: 14px; font-family: Calibri, sans-serif; "><br></div><div>I'm a total Pi newbie – I don't even own one yet. <span style="background-color: rgb(255, 255, 255); color: rgb(34, 34, 34); ">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.</span></div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); "><br></div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); ">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 <b><i>variable</i></b> 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…)</div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); "><br></div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); ">Any help greatly appreciated!</div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255); "><br></div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); "><span style="background-color: rgb(255, 254, 254);">Best,</span></div><div style="margin: 0px; padding: 0px; border: 0px; vertical-align: baseline; color: rgb(34, 34, 34); "><span style="background-color: rgb(254, 253, 253);">Dan</span></div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">--</div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">Dan Nigrin / Defective Records / <a href="http://defectiverecords.com/" target="_blank">http://defectiverecords.com</a> </div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">CycliC, M185 & Klee Sequencers / MC-4 & MC-202 Hack / Audio Plugin Player / General MIDI Player / Major Malfunction</div><div style="font-size: 14px; font-family: Calibri, sans-serif; ">Jack OS X / <a href="http://jackosx.com/" target="_blank">http://jackosx.com</a> </div></div><br></div>
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