Doing a little research, thought I'd post my idea in case anyone has any thoughts to contribute. I would like to add two features to a GRBL setup that think would make some functions possible for Plasma cutting and a decent LCD display. The standard setup for GRBL is: --> PC/G-Code Sender --> GRBL --> Drivers --> Motors With a Serial Proxy like XLCD, the data stream looks like this: --> PC/G-Code --> XLCD --> GRBL --> Drivers --> Motor |-------------------------------> LCD If the arduino running XLCD is fast enough, my thought is to configure it like this to satisfy an external THC module for plasma cutting: THC |--> PC/G-Code --> XLCD --> GRBL --> Drivers --> Motors |-------------------------------> LCD Of the two types of common THC, one sends up/down commands that could be interpreted by the XLCD module, and can insert G-Gode commands in the data stream to GRBL that moves the Z axis up and down. The XLCD module could also be programmed to insert the appropriate delays or feedback from the Plasma/THC for starting the arc, and resuming the cutting once the arc is established. In the case of my machine, the XLCD could have this functionality disabled for standard milling. Just thinking out loud, but if a standard Arduino could process quickly enough without bogging down the g-code stream from the PC, then I think this would be a rather straight forward way to impliment these features. Link to XLCD: https://github.com/xpix/XLCD/wiki Any thoughts on this would be appreciated... I haven't had the time to really sit down and pic apart what is already available in the XLCD code set.
After thinking about this a little more, I don't think it'd work for the Plasma/THC. The reason is that a single G-Code generate a long motion in the CNC, which would require many THC adjustments within. I do like, however, the concept of using a second Arduino to spy the G-Code stream to operate an LCD. I may still explore this. For the THC - there is a second type of THC that intercepts the Step/Dir signals and adds additional up/down commands for them. I may give this a try.