Page 1 of 1

No signal on Z endstop terminals + messed up endstop lables

Posted: Sun Oct 11, 2020 2:00 pm
by miron
Hello,

I'm looking for help with a weird issue where I get no signal on the Z endstop terminals. X and Y get 5v but the Z is dead. Also on top of that X and Y endstop terminals are switched so I need to wire X endstop into Y terminals and vice versa. Any suggestions on how to fix it? I'm guessing the pin assignment in GRBL is messed up - how should it look to work correctly?

This is an issue only with this shield. My old Chinese shield worked fine (until it died) with the exact same config. I've tested this on 2 Arduino Uno boards so I'm sure it's not a problem with that.

I'm running v1.1h (2019-08-25) release of grbl.

Thanks!

Miron

Re: No signal on Z endstop terminals + messed up endstop lables

Posted: Wed Oct 14, 2020 4:44 pm
by EccentricWorkshop
I'm not sure about the switched X and Y; it hasn't come up before from anyone. The GRBLDuino Uno Shield schematic (last page of the attachment below) shows them connected to the Arduino's D9 pin for the X limit and D10 for the Y limit which matches the pin mapping found in the cpu_map.h file of GRBL 1.1h. You can verify this on yours by probing for continuity (with it unpowered) between the left/bottom pin of the terminals and pins D9 and D10. If this is truly an issue on yours, you can swap the two pins in the cpu_map.h file, compile GRBL, then upload it to your Arduino.

With the Lim. H/L jumper set between the H (bottom) pin and center, the right/top terminals of the limit switch terminal blocks should have 5v on them. You shouldn't get 5v on the other terminal in the block because the Arduino pin is set up as in input to take a signal of either 5v or 0v depending on configuration.