knock sensor into DL1?

[sideways-dan]

Is it possible to use an analogue input on the DL1 (mk2) for a knock sensor? my ECU is not capable of knock sensing so it would be nice if i could get the data logger to record it and then i could use that information to display a warning on the dash.

from what i understand the signal wire from the sensor outputs a voltage which spikes when it sees knock. this should be easily displayed in the logs. the alarm may be a little but more difficult (for me anyway). the spike in voltage may only last a very short time so that would have to be picked up and the alarm signal extended. i would need something in the equation that i have that flashes the shift lights on the dash 3 when an alarm is activated.

Anyone have any ideas or experiences?

Thanks, Dan

[Support]

I would strongly suspect that the duration of the signal from the knock sensor will be way too short to do anything useful with this, you would really want to be sampling the data massively faster to do anything useful with it.

Martin

[sideways-dan]

would it be long enough to be captured and be viewed in the analysis software? I would have thought that 100hz with no smooth over should be enough to capture any knock.

[Support]

I would be surprised, if you think that at 3000rpm you get 50 rotations per second, the main combustion event is over in 1/4 of this, so if you sampled at 200Hz you would have 1 sample during the combustion event on one cylinder, you are looking for something which happens during a small fraction of this time.

Martin