as always - long and painful https://youtu.be/RErLu73-Xno
On Wed, Nov 25, 2020 at 11:44 AM Sam Sokolik <samco...@gmail.com> wrote: > Mainly showing how low the frequency responce is... You can already see > the phase shifting and much faster than 1hz it gets worse plus > attenuation... > > On Wed, Nov 25, 2020, 11:19 AM John Dammeyer <jo...@autoartisans.com> > wrote: > >> Sam, >> I'm not sure what the purpose of the 1 Hz sin wave modulation is. Why >> and what are you trying to show with that? >> John >> >> >> > -----Original Message----- >> > From: Sam Sokolik [mailto:samco...@gmail.com] >> > Sent: November-24-20 8:21 PM >> > To: Enhanced Machine Controller (EMC) >> > Subject: [Emc-users] Interesting observations with a cheap bob's analog >> out. >> > >> > Granted.. I know these are pretty basic. You can usually find them for >> > under 10 dollars. They do work quite well though. I was working on >> some >> > youtube content and was goofing around with this bob and the printer >> port. >> > Setting up a pwmgen to test the analog out unearthed some things.. >> > >> > -It isn't very linear. lincurve is your friend.. It can be off by as >> much >> > as .5v over the range. >> > -it is sloooowwwww. It is most likely a simple low pass. The photo >> here >> > is of a 1khz pwm signal modulated by a 1hz (yes - hz) sin wave. You >> can >> > already see it is phase shifting. 10hz and it is attenuated to about >> 2v >> > p-p. >> > -the pwm frequency didn't really affect the linearness or performance. >> > >> > http://electronicsam.com/images/greenmachine/IMG_20201124_183913.jpg >> > >> > one of these bobs... >> > >> > http://electronicsam.com/images/greenmachine/IMG_20201124_183919.jpg >> > >> > Still pretty cool what you can do with the printer port still ('I'm not >> > dead yet!') and rt_preempt. (50us base thread) This could be why I >> wasn't >> > able to get a very tight spindle speed control on the little emco lathe. >> > (I am using this bob's analog out driven from mesa pwm) And you are >> > certainly not going to control an analog servo with it ;) >> > >> > sam >> > >> > _______________________________________________ >> > Emc-users mailing list >> > Emc-users@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
