With tinyG energized (does not have to be moving), probe the Ymin lead at tinyG while you operate, then release the limit switch, monitoring the voltage. It should toggle between 3.3v and ground.
I performed this and when the switch wasn’t tripped the VOM read .03 volts. When the I tripped the switch the VOM read .11 volts. I checked all my other switches to see how they would react and I would read around .03 volts before they got tripped and when they were tripped they would read 3.1 volts.
So now, with tinyG energised but the motors relaxed (by default, this is two seconds after a reset), manually move your Y toward 0 and observe the voltage at Ymin. Is the gantry movement mechanically triggering the switch, causing Ymin to go from ground to 3.3V(on voltmeter)
I performed this also and just as before the Y Min lead would read .03 volts before tripped and just .11 volts when it was tripped.
Here are the parameters I have on the Tiny G.
Tiny G Settings
