2013/5/30 Jon Elson <[email protected]> > 5 ns is only one instruction. Do you think it can read, say, the 3 > signals from 4 encoders > and keep count, all with only one instruction? Not possible. It would > probably take > 20 -30 instructions for each encoder channel, and possibly quite a bit > more. > Assuming one PRU was dedicated to encoders, that would mean sampling the > encoders at about a 1 MHz rate. This is still fantastic (if my totally > off-the cuff > guess at how many instructions it takes is anywhere near correct) and an > incredible improvement on reading encoders via the LinuxCNC encoder > HAL component. I would not be astonished to find out that it actually > takes 200 instruction per encoder, reducing the rate to a 4 us sampling > period. > Still, not bad at all, and will handle many hobby-level machines. >
Talking about encoders, Beaglebone must be good with serial ones. SPI should not be a problem at all, but what about BISS? I got a few very nice motors with those encoders, and I'd like to test them at least. Anyone knows something about BISS on Beaglebone? (advices on MESA solution welcome too) Andrew ------------------------------------------------------------------------------ Introducing AppDynamics Lite, a free troubleshooting tool for Java/.NET Get 100% visibility into your production application - at no cost. Code-level diagnostics for performance bottlenecks with <2% overhead Download for free and get started troubleshooting in minutes. http://p.sf.net/sfu/appdyn_d2d_ap1 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
