Hi folks. Running into an issue with my setup flashed with GRBL 1.1f and not sure if this can be fix via configuration or if I have a faulty CNC Shield board. With nothing connected to the end stop pins, I'm getting a triggered alarm only on X. When I do a $5=1 command, I get a Y & Z alarm so it seems like only the X stop pins are inverted. Is there a way to invert only one axis? Some insight will be greatly appreciated. Cheers!
That sounds like a short to ground. The inputs are normally pulled high on the Atmega so somewhere the circuit is pulled low. A visual inspection is called for. Then pull the 2 boards apart and see if you still get the error. If it goes away it's the shield or the connection to the shield. If it remains, it's the arduino. Look up which arduino pin is the x limit and inspect both boards with magnifying glass or scope
And if it was incorrectly wired at some point, the Arduino pin on the chip might be damaged internally (overvolt, dead short without resistors, etc) , in which case replacing the arduino will do
Yes, that is also a very real possibility though, if only used for GRBL, it's less likely since the pin would have been in input mode. Some of the chinese arduino knockoffs have some sloppy soldering and bad PCBs.
