I have GRBL .9j running on a genuine UNO. I'm feeding it with the Universal Gcode Sender. I'm having issues with pause commands. I'm running a CNC on 2 of the three axises of my mill. I still have to set Z manually every time it transits. I have several programs that work perfectly without any pauses, but because they don't ever adjust the Z axis, the tool gets dragged around making a bunch of unwanted cuts. I've added a bunch of pauses to allow me to manually adjust Z and then restart the cycle. First I attempted to use ! the GRBL the feed hold command. Unfortunately that stopped everything as soon as the command was sent, even if there where commands in the queue to be processed. Then I switched to M0 and M1 commands. The machine stops predictably now, but on the restoration it seems to jump ahead of where it should be. It sometimes it will skip a whole series of commands. However, I am getting confirmation that the command was sent and the return OK.
Anyone have any insight?
Thank you