Hi everybody

I have a question about using this sensor as a main reference to nail some glitchs under the bonnet.

I need to get rpm from the crankshaft sensor via math channel. As far as I know we have to use the math fuction freq(channel) to acomplish this but all I get is a flat line in my scope ( 4423 and 6.9.14.16).

The fuction I am using is: (freq(A)*60)/60 of course this is equivalent to freq(A) but anyway all I get is a flat line in the upper side of the screen.

I was been told that it is useful the derivative of the signal and try to get the peaks on the derivative to get the time of each falling edge on the signal and knowing the crank angle between the falling edges, do the calculations to convert time to RPM and then filter the signal missing points. Any suggestion?

I think this is the strategy TiePie guys use in their program

It would be nice being able to calculate RPM many times for only one crankshaft revolution so that we will be able to see individual changes as long as every single cylinder contributes to engine power. I think the current software version is able to do it but I don't know how to do it yet!

Another issue is about the trigger for this signal. I used to use the "interval" type and condition "greater than", so I noticed than sometimes works. So I would like to know what is the best trigger for the crankshaft position sensor inductive type as well.

Thanks in advance

Dario