On Sunday 02 May 2021 05:58:24 Thomas J Powderly wrote: > Hi Gene > > On 5/1/21 8:32 PM, Gene Heskett wrote: > > On Saturday 01 May 2021 09:12:41 Thomas J Powderly wrote: > >> Hello > >> here is an esp32 stepgen for linuxcnc > >> > >> this snuck under my radar, i missed it by a few months > >> > >> it maybe of use > >> > >> The example setup was > >> > >> laptop > eth > w5500 module > esp32 > stepper drives > stepper > >> motors > >> > >> the video shows the linuxCNC logo running and a single closed loop > >> stepper > >> > >> https://www.youtube.com/watch?v=_Goi4YVU0js > >> > >> the github has the code > >> > >> https://github.com/Deotti-cl/linuxcnc-esp32 > >> > >> i haven't looked hard yet > >> > >> but i think the comms are really spi > >> > >> and so it might hookup to a pi with a very short cable. > >> > >> tomp > > > > Looking at the driver, no, its udp over ethernet. > > you have to how he solved his problem. > > He used udp, true, but the info flows from a laptop to an ethernet > port to a w5500 > > which connects to the esp32 thru spi. > > So the ethernet and udp is not needed if a raspberry pi replaces his > laptop, > > and spi is used to the esp32. > > Yes his driver uses udp, and his hdwr converts the packets to spi. > > I think the system can be simplified with a new driver. > > >> _______________________________________________ > >> Emc-developers mailing list > >> Emc-developers@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > Cheers, Gene Heskett > > on another note: > > MXMaster has re-written the arisc driver (stepgen) for orangepi > > I am running it now with great video, AXIS, and 6meters/minute, > > And I have just gotten (same as you) the servo-steppers > > """ > > Three-phase 57 Series LC57H380+LCDA357H nema 23 closed loop stepper > motor and drive > > """ > > They were a great deal off alibaba at 50 bucks each with 21$ shipping > each. > > So, I can bench test these crazy fast steprates. > Actually, thats no faster than a normal 2 phase, because they are both using BBLB opto's in the control interfaces. So they'll likely puke and stall before they get to 300 kilohertz step rates. I have gotten to 300 kilohertz using a function generator as a signal source so I can optimize the step pulse width as I speed it up. But thats a very critical brick wall, and the stall instant is impressive with its violence, the motor jumps several inches up in the air if not restrained. To get any great amount faster will require switching those opto's out for a texas instruments charge pump like capacitatively coupled isolator. A tech I've not kept up with as it also has a speed limit in the sub-5 megahertz range the last time I looked. Then of course the ultimate limit is the coil inductance of the motors vs the supply voltages needed for the higher speeds. To get above 3,000 rpm with any useable amount of working power is going to take a new generation in switching transistors with much higher voltages just to overcome the inductance. And at some point, the comms folks like the FCC are going to yell about the emitted RFI. They have rules now, but very poorly enforced for lack of manpower, so its considerable now, to the extent my wireless, portable house phones can't be used in the garage within 15 feet or so of one of my machines.
Because switching is the only way to fly even for servos, both are guilty of being noisy as can be. Some of that noise ca be contained by useing Clark Wire & cables "star-quad" microphone cable which is very well shielded for the motor cable, but its also a little small for a 5 amp motor, heating just enough to notice. I'm only switching the h-bridge driving the bs-1's servo motor at a measly 4 kilohertz, but I can hear it in my house phones using the 2.4 gigahertz band. The actual switching in those BTS 7960 half bridges is that fast. Its also why there is zero heating at 24 volts in a teeny little board rated at 43 amps at 27 volts, even if its running at 50% continuously. In short its an amazing board for $6.13/copy, but its also a noisy SOB. Noisy because the motor cable supplied with the motor isn't at all shielded, just simple twisted pair. I have petitioned Susan Clark to have a 20 guage version made, just for stepper motor wiring, but it hasn't happened. For a 24 guage, with 120 db of shielding, its as supple as overcooked pasta, and right at home in a crowded cable chain. > > take care & stay safe I'm trying, taking all the reommended vitamins and trace elements and have no intention of taking the "jab", its a future death sentence the nedxt time you are exposed. OTOH, at 86, how much longer do I have either way? Artificial help is whats keeping me going now with a pacemaker and a TAVR in my heart already. And 8 years left in the pacemaker battery. You do the same TomP. > tomp > > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
