Marlin endstop read

Hello, im looking at the code but could not find (under my limitations) how does marlin evaluate an endstop trigger event. i have modded the classic endstop with an opto switch i had lying arround. the curious bit comes from the fact that while i was recalculating the Z offset i saw the led brightness was proportional to the the opto endstop trigger level (height), yet M119 did not report the event until a few 0.0Xmm lower.

i saw a few lines calling READ

bool y_min_endstop=(READ(Y_MIN_PIN) != Y_MIN_ENDSTOP_INVERTING);

but im failing at see at which level this will be true

Endstops are only digitalread. That means it can only read 1 or 0.
Now there are two different switches. NO and NC. So maybe you need to invert that.

---

Triffid Hunter's Calibration Guide

--> X <-- Drill for new Monitor

Most important Gcode.

thanks Wurstnase it does work, but I was worried since i was not sure if the trigger was a some analog read