Logging AC signals

[dr-z400]

Hello. I am trying to capture a signal with Arduino 5V digital pin. The signal is generated by a pickup coil for a CDI type motorcycle.

Here is a link to the signal waveform: DRZ400 PICKUP COIL CRANKING - YouTube

From this information, I should be able to log it to the digital pins of Arduino (5V) by adding a high ohm resistor, a zener diode (to limit (+) voltage to 5V max) and a normal diode (to remove the (-) voltage). Am I right?

Based on the electrical diagram, it is the Blue(+) and Green(-) wires.

I have a basic knowledge on electrical engineering. Can you advise what resistors, diodes and wiring diagram please?

I've read that the signal circuit has to be of high impedance so as not to modify the pickup signal. Is this correct?

Is there a way to refine this signal such that the input to Arduino is a clean one?

I'd like to log this information to determine RPM and TDC/BTDC subsequently. Any advice is appreciated. Thank you.

[MarkT]

dr-z400:
Based on the electrical diagram, it is the Blue(+) and Green(-) wires.

What electrical diagram? What CDI pickup coil?

[dr-z400]

MarkT:
What electrical diagram? What CDI pickup coil?

Yes. The electrical diagram shows the output of the pickup coil.

[MarkT]

I see no diagram, so I repeat my questions.

[raschemmel]

Capacitor Discharge Ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars.

CDI