Converting 0-12v square wave to 0-5v square wave for tachometer

Aftermarket automotive ignition systems output a 0-12v square wave for a tachometer signal. Racing data recorders and modern autos use 0-5v inputs. There appears to a large market for a device to do the conversion and possibly add some filtering. I’d like to know if the BOB-09118 can be used for this purpose. I couldn’t find any instructions on usiing it for specific situations. Any help would be appreciaated.

Should work, you will need to add a resistor to the input side of the board though because I believe it’s setup for 5 volt logic.

I suggest to add 1K to 2K to the input side of BOB-09118. 1K, plus the on board 220 R would limit the LED current to 10 mA. The absolute maximum per input LED is 30 mA.