Increase sensitivity of the knock sensor interface

[masterx81]

Hi!
In case of single sensor, wouldn't be interesting to check also the 2nd harmonic of the signal?
The tpic permit to program the bandpass frequency up to 20khz, most engines have base frequency under 10khz, so it's easy to program the second channel to the double of the base frequency (i've seen in the pdf that it's possible to have different settings for both channels). So, we connect the single sensor to both channels, if we get detontion on the first channel, we can check if also on the second channel the signal have passed the background noise (much less at higher frequencies). This will limit a lot the false positives due to background noise, and maybe detect easyer a not-so-bad knock.

[AbatelliCristian]

I think is good idea.

Attach photo analisy knock file

[tpsretard2]

I would second this idea also as long as you can log both.

But you can always just input the harmonic frequency