Rotax engine tachometer help

Hello, I’m trying to measure RPM for a Rotax aircraft engine. The signal you get from the engine is described in the attached picture below. Can anyone help me with that? Do i have to limit the voltage? i beleive i have to connect it to a digital port and mesure the pulses somehow, 1 pulse is one rotation of the engine.

rotax tachometer specs.PNG

The image from the OP. How to post images.

1k series resistor, schottky diode clamps to the 0V, 5V rails, LM339 comparator (compare to about 1V?), pull-up resistor, Arduino pin

(Actually make that 4k7 series resistor, don't want to pull the 5V rail up in voltage...)

Thank you for the reply MarkT, I just got the LM339 , the resistor, etc... and i'm trying to find out the connection diagram. I have very basic knowledge on electronics and i'm prety lost trying to understand how to connect them. I got the mainidea which i believe is to convert the analog signal to a square digital signal for the arduino digital port to be able to recognise it. I beleive we have to use one of the 4 inputs of LM339 and get an output for the arduino port. I its not to much trouble can you please upload a conection diagram?

I am quite new to electronics and arduino and i am facing exactly this problem. Please did you eventually get this to work and what circuit diagram did you use.

hi, someone still working on this project? I'd like to realize sometnihg similar, but I have a very low knowlege on electronics ad arduino, too...