Noozer wrote:
Anyone have a simple digital tachometer schematic handy?

I want to put a 4 digit LED tach into my van. Resolution of 50rpm is fine.
Fed by the TACH output of a six cylinder GMC on distributor coil.

If it isn't much more difficult, I'd like to be able to drive a bar graph of
12 to 16 LEDs as well.

How about doing it the old-fashioned analog way ? An
LM2907/2917 as F-V converter, and a 4 1/2-digit DVM module
for readout. Another venerable IC, the LM3914 could provide
the bar graph display, two of them for a 20-dot scale.