[BlakusSenior]

Hi All,
I have a hobby Woodpecker mill and am using Grbl with an Arduino shield to control it for PCB milling.
I can run programs OK but can't seem to find a way to set z zero, I get an error if I try "G38.2 z-.5 F5" and using the leads connected to the probe terminals (is 5v on the pin 5) does not stop the down movement.
Any help appreciated.

Cheers ...... Mike B

[109jb]

What control software are you using and what version of Grbl?

Probe pin works by completing the circuit from Pin A5 to ground. Some control software has an indicator for when the probe input is triggered. If not, you can see it in the status report. Test that the probe input is working first and that it is working correctly. If using a probe that breaks the electrical contact on physical contact, you will need to invert the probe pin. There is also a config.h option for Grbl to check the probe input for the correct (no contact) at the beginning of the probe cycle. This will detect an improperly configured probe, or a probe that isn't reading correctly at the start of the cycle.

[BlakusSenior]

I use Grbl 1.1 and also for the control. My problem is that the probe wiring does not stop the motion. The pin A5 is held high internally with the Arduino and shows at 5v when open and zero when closed. AFAIK the Arduino is using a library called "probe.h"