- Thu May 28, 2020 12:23 am #43194
A straight open-collector pulse from the UAF2115 chip on the back of my cluster (from a 1993 Volvo 240) into the flex input with the onboard 2.49k pullup to 5v resulted in some wild fluctuations in speed at idle. It would jump randomly from 3-15kph, and increase proportionally while driving. I once saw 400kph! The filtering/smoothing didn't work, but I don't know if that's due to the signal I was using or a firmware issue.noisymime wrote: ↑Sun May 24, 2020 10:44 pmYou can use the secondary trigger input (if not otherwise used) or any of the other 'interrupt enabled' inputs. If you've got one of the newer boards with an Ethanol/Flex input broken out, that works well.
The signal was perfect with a 330 ohm pullup to 12v on top of the onboard 2.49k ohm pullup to 5v, but that voltage would have killed my ecu pretty fast I bet .