Chris, I must admit I had a bit of a chuckle when I read your answer. It's so easy to just do this or use that or add these and then you are good to go.
If it's that easy I expect you'll have that tablet with the wifi connection to the ESP32 and be executing G-Code by the end of August right? Other than wiring up motors and all the mechanicals, which has to be done for any CNC installation the time to get the CNC running was even less time than from now until the end of August for me. And I likely would have been using this were it not for the inverted ESTOP. https://youtu.be/9GF709ZfLRQ Instead I went the PC route and did a dual boot between LinuxCNC and WIN-XP for MACH3. After that I bought the MESA 7i92H after also mucking around with my USB SmoothStepper (MACH3) from my CNC router. I decided Linux had a better future than WIN-XP so although I still run MACH3 on the CNC router the mill has LinuxCNC. On the workbench I muck around with a Pi4 and MESA 7i92H. Go onto you tube and search Raspberry Pi and LinuxCNC and there are lots. Again one like this is much faster to set up than your suggestion and not any more expensive. https://youtu.be/qL530kJUmII I do look forward to your progress on that novel idea of a tablet, ESP32, RTOS and all the code to deal with trajectory planning. Keep us informed. Maybe some videos of the intermediate steps. Especially since as you imply it's so easy to go that route. It would be interesting if you could do it for less than https://youtu.be/X-DY6iL6NcI John > -----Original Message----- > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > Sent: August 5, 2023 4:02 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Beaglebone black latency > > Why start with a BBB/Pi4 and then add a screen and so on. > > A better starting place would be a low-cost Android tablet. Perhaps like this > one. For $120 you get the CPU (that runs Linux), a touch screen and WiFi. > What is needed is a way to connect it to a machine tool. > https://www.bestbuy.com/site/samsung-galaxy-tab-a7-lite-8-7-32gb-with- > wi-fi-dark-gray/6464584.p?skuId=6464584? > Samsung Galaxy Tab A7 Lite 8.7" 32GB with Wi-Fi Dark Gray SM- > T220NZAAXAR > bestbuy.com > > I would use something like a small 32-bit micro controller to do the > real-time > pulses and switch monitoring. If you would choose an ESP32 then the > interface to the tablet is wireless. But you could use USB as both devices > have USB built-in. USB has a built-in asocronus mode where data moves in > strict real-time. But this might not be needed if 100% of the RT loops are > onthe microcontroller. > > The ESP32 is a dual-CPU, 32-bit device with more then enough computer > power to run a CNC controller. I would 100%, for sure run an RTOS > (FreeRTOS or Mbed) on the ESP32. The tablet is just the user interface and > �MPG�. > > I am currently using ESP32 to generate PWM control for a 12-axis robot and > I�m getting sub microsecond pulse accuracy which is more then my > application needs. It is very fast and written 100% in Python. > > If the user already had an Android tablet or wanted to buy a used tablet you > really could under cut the cost of a $500 Chinese device. > > LCNC was written to take advantage of �cheap� community hardware. This > is when a basic 16-bit PC would sell for �only� about $3,500. Today�s > commodity hardware is called a �cell phone� and they are MUCH more > powerful then the old PC was. > > > > > > > On Aug 5, 2023, at 3:23 PM, John Dammeyer <jo...@autoartisans.com> > wrote: > > > > Me too. A closer look at the fine print and selecting the correct button > shows the actual CNC controller is $513 or $541 for 3 or 4 axis respectively. > The MPG is priced separately at $96. > > > > And this is why a BBB with a cape that included a Break Out Board with a > few relays etc. for under $100 would be quite the bargain. The question is > then what sort of display would be good. And you still need some sort of > MPG to go with it for also about $100. > > > > For $94 I can get, from amazon.ca a 7inch HDMI LCD (H) 1024x600 Monitor > IPS Screen Capacitive Touch Display Supports Raspberry Pi Jetson Nano > BeagleBone Black Banana Pi & Microsoft XBOX360, Sony PS4,Nintendo Switch > > > > And therein lies the problem. Creating something similar to the $500 > Chinese CNC controllers with touch screen will ultimately cost in the same > $500 range. But unless the MachineKit or LinuxCNC version is stable with a > target life similar to the life of the machine tool no one will spend the > energy > and time to make that. > > > > The market isn't big enough to justify the work required. Which is why so > many of the Beagle Capes are no longer available. Next week there's an new > ESP32 with more bells and whistles. Won't do what the Beagle does but ... > > > > John > > > > > >> -----Original Message----- > >> From: Martin Dobbins [mailto:tu...@hotmail.com] > >> Sent: August 5, 2023 11:44 AM > >> To: Enhanced Machine Controller (EMC) > >> Subject: Re: [Emc-users] Beaglebone black latency > >> > >> It makes me wonder which operating system they put on that Chinese > >> controller, and what motion control system. > >> > >> Martin > >> > >> ________________________________ > >> From: John Dammeyer > >> Sent: Friday, August 4, 2023 7:41 PM > >> To: 'Enhanced Machine Controller (EMC)' <emc- > >> us...@lists.sourceforge.net> > >> Subject: Re: [Emc-users] Beaglebone black latency > >> > >> My biggest issue with the Xylotex BBB Cape for CNC was that the logic for > >> ESTOP was inverted. ESTOP was a N/O switch so if a wire was broken you > >> wouldn't find out until you tried to save a body part from being injured > with > >> the ESTOP. > > > > > > > > _______________________________________________ > > 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
