Hi, I have this circuit that is basically 12v that goes down to 3.3 for a pin of a microcontroller.. its work perfectly but if the voltage goes up, then of course the current that goes through R2 rise as well, if it does, the zener lose the current that makes him work. I need to p[rotect the pin at all cost, so there an a efective way to protect the pin? There an effective way? It can be another circuit

 

You already have two threads on this topic (soon only one).
https://forum.allaboutcircuits.com/...m-accidental-overvoltage.203226/#post-1939776