RPM data to Arduino

[1durgasriram_144]

My bike have an Tachometer wire from ECU to Bike Dashboard(Digital) which shows the RPM in bar. So i want to read the data from the tachometer wire with Arduino .so for this 1st i have tested the wire with multimeter for voltage readings then i got 7volt when engine is in off state and 4 volt fluctuating in engine on state and when i rev the engine the 4 volt is not getting changed much.so then i tried with voltage divider connection which consists of one 10k and one 5 resistor connected to D2. but i'm not getting the proper data ,so can anyone help me to read this and print the output data in searial monitor

[gilshultz]

Connect a scope to it, I think it is either PWM or VPWM.

[1durgasriram_144]

i dont have any oscilloscope or something , and thanks for ur quick response

[the2ndtierney]

Hello,

Can you clarify the difference between this post and your other one?

Bike RPM Signal to Arduino input

Hello guys,I'm new to the form ,I need a help for reading bike rpm signal to Arduino input, my bike have an inbuilt rpm signal wire which directly comes from ecu to dashboard,so I want to read the data from it ,so please help me in this guys, I have used a voltage divider as the bike rpm signal will be in 12v but the values showing in serial monitor are not understanding for me as each time showing a new value ,so if anyone have completed this previously,help me out

[1durgasriram_144]

yeah , previously i just asked help with the basic information and in the next post i have clearly mentioned what i am going through and what the stuff i have like voltage readings and all. Sorry if i have done anything wrong or violated any guide forms.
thanks for ur response

[DaveX]

Code?

I'd check the voltages at the divider and then try FreqCount Library, for Measuring Frequencies in the 1 kHz to 5 MHz Range