J Oliver wrote: > > 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…)
You can add a resistor and capacitor to build a RC filter, and you'll get a voltage out of pwm. You will have to experiment with different values to get something stable and fast enough. See these pages for some information about that: http://jeelabs.org/2013/06/30/from-pwm-to-voltage/ http://dev.emcelettronica.com/how-to-use-pwm-to-generate-analog-or-analogue-voltage-digital-circuits-part-2 http://sim.okawa-denshi.jp/en/PWMtool.php As of 3.3V to 5V you can use a transistor before the RC filter. -- Charlot _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
