I got a z probe to do a semi-automatic tool change, its normally closed.
The problem is that I cannot mix this probe with a touch plate because it’s normally open, its there a way to use the estop pins to use the the z probe?
If not, I can make a normally closed touch plate, but don´t know if I can set grbl to use it in that way.
You can convert a NC circuit to a NO (and vice versa) with a jellybean BJT and a resistor or two. I also have a NC work probe that required an interface circuit to function properly with the C3D board. I don’t believe it’s possible to use an e-stop input for probing unless you’re willing and able to hack on grbl itself to accomplish it.
I would recommend converting your z probe to make it NO and then just placing it in parallel with the touch plate. The C3D board’s probe input is pulled up to 5V and is active-low. If you’re comfortable reading a simple schematic and wiring it up, I can document what worked for me.
Hi Sean!
Yes it will be nice to have those shematics, 
Here you go. This is what worked for me.
Sorry that the schematic is re-drawn from memory; the exact identity of the NPN transistor and value of the resistor aren’t top-of-mind, but they’re not critical in either case. I want to say I used something like a 2N2222. Just make sure not to exceed your transistor’s base current specification - with a 10k resistor this ends up being in the ballpark of 0.5mA which is fine for a 2N2222.
Thanks!
I will try this as soon as I can find an electronic store open jajaj. 
Take a virtual beer! 
It worked great!
Thanks
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