LETARTARE
commented
10 years ago I do not know if this will solve your problem, but you can try using this new version : https://github.com/zapmaker/GrblHoming/tree/Letartare it has a button 'Pause' which uses "! (feed hold) " and " ~ (start cycle) " regardless of hardware inputs.
Seeing some incorrect feed hold behavior in 3.6.1 that I can't reproduce in 3.5 (albeit in different operating systems):
Case A (Failing): While using the included code, GrblController 3.6.1 (Windows) fails to feed hold; feed hold is ignored and the code finishes and returns "Code sent successfully with no errors," without me pressing the cycle start button (connected to A2) at the programmatic feed hold ('!').
Case B (Working): While using the same code and machine, GrblController 3.5 (Mac) correctly feed holds; code pauses at '!' until cycle start (A2) is pressed.
Background: -I've verified that "Filter file commands before sending" is ignored in both cases. -Using Grbl 0.9g -Autostart set to false ($14=0) (not sure if this is important)
... Gcode (parenthetic comments added here for explanation) ... (Put machine in known good state) $H G53G0X0Y0Z0 G92.1 G10 L2 P2 X0Y0Z0 G55 G20 G90
(Position gantry for tool change) G0 X-0.325 Y-.75
(In Case B, machine pauses here to change tool, but doesn't in Case A) !
(feed hold doesn't appear to stop until the buffer clears, so I've copied the previous command 16 times to ensure the buffer flushes out; not sure if this is incorrect GRBL behavior*, but it's irrelevant here) G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75 G0 X-0.325 Y-.75
(Cutting commands begin here with the new tool) G0 Z-0.3
... *I've filed a bug report for this issue here: https://github.com/grbl/grbl/issues/465