I'm looking for a way to generate a bang when my LFO signal changes direction. Something in my distant memory leads me to think this could be accomplished using the second derivative of the LFO signal and looking for zero crossings.
I looked on here for "derivative" and found a couple posts about ten years old. I also seem to remember that a high pass filter is a "differentiator" but certainly the corner frequency must get involved in some important way. If I had a delay line with 2 taps coming out I'm pretty sure I could generate something suitable.