Rules for projects section?

[davidsrsb]

If you are talking about this one, it did involve KiCads ngspice interface, so a tenuous connection at least.

[SOLVED] OpAmp-based logic level tester in ngSpice

Hello! I am struggling with simulating the attached circuit in ngSpice. It is meant to be a logic level tester, so when the voltage is above a certain threshold (set by the potentiometer midpoint VBIAS), it would light up an LED. However, OpAmp U1 (LM324) seems to switch regardless of the voltage on its inverting input. Since I am new to KiCad, I am not sure if I got the right SPICE model for LM324 (and I found it by googling anyways). Could anyone who can code in SPICE help me understand if I …