Thanks for the information. It is good to hear the voice of experience.

As for GRBL development that seems to have stopped or slowed down to a significant extent on all platforms. It is my understanding that one of the key developers is working with on a major rewrite of the code to be more modern and to prepare to better leverage more advance hardware. I have no idea if this is what is actually happening at the moment but many of the repos have not seen significantly can’t updates in a long time.

I don’t see this as a bad thing as it highlights that the current versions of GRBL are pretty reliable. One can only hope that the refactoring is still on track because this should permit far more functionality on ARM.
Quote Originally Posted by jfong View Post
Even though I use Linuxcnc, mach3 and UCCNC on my machines, I play around and compile test every grbl, marlin, smoothie etc port that is available.

ESP32/grbl is the newest port but still some rough edges. I like it but slow usb serial. Plenty fast for 3axis cnc but too slow for laser raster engraving. Neat WiFi web based interface available.

LPC1769/grbl-lpc is what runs my CO2 laser because it is the fastest grbl port available. The development has stopped and there are some features of original grbl that still hasn’t been ported over. 4 axis only. Over 100khz step rate. Fast raster CO2 engraving capability.

STM32/grbl is a mostly a full grbl port with 6 axis capability. The STM32 is 72mhz so not as fast as the 120mhz LPC1769. Good enough for 95khz step pulse rate. New dev has picked up development work and added new features and bug fixes.

Mega2560/grbl is a full grbl port but hindered by the 16mhz atmega2560 speed. Up to 6 axis available. About 30khz step pulse rate.

Uno/grbl. This is the original master code running on a atmega328 arduino Uno. The most reliable and stable version. Max step pulse is about 30khz. I would recommend using this version for beginners since it has the most users and knowledge base. 3 axis only. Arduino Uno is cheap to buy.


For a full featured controller on a budget. You can’t really do better than free Linuxcnc running on a spare PC laying around. If it doesn’t have a built in parallel port for I/O, a $8 pci parallel port card can be purchased. Linuxcnc isn’t the easiest to configure though.
I wish it was that easy to find a suitable PC just last I got around. The other problem is that most of these old PC’s are massive boxes often bigger that the machines they are driving. As such I’m not a big fan of going the old PC route. A small PI, Odroid C2 or similar card running a G-Cide sender seems like a better solution these days s. A complete controller can be easily bolted to the machines that are likely to be driven by such controllers.