how crank decoding exactly works ??
Posted: Thu Oct 25, 2018 6:11 pm
hello guys im trying to understand exactly how the decode of the crank is working.This is what i have understand so far
so by using a RISING interrupt we get the teeth number that pass the sensor plus the time the interrupt happened plus the interrupt duration
and the previus tooth interrupt time and duration.(lets use 12-1 wheel) then buy doing 360 / 12 = 30 we know eatch tooth is 30 degres
so if we are at tooth 10 we are at 300degres. now if we want to add a spark at 30deg before tdc we do 360 - 28 so the spark should happen @332 deegres.
now we know that each toth is 30deg so 332 is 11 teeth plus some time. now what i dont know is how to get exactly the 332 deg from crankshaft reading also how to handle the full engine cycle aka 720 degress rotation and how to add the TDC angle offset becouse tdc could be tooth 4 for example
so by using a RISING interrupt we get the teeth number that pass the sensor plus the time the interrupt happened plus the interrupt duration
and the previus tooth interrupt time and duration.(lets use 12-1 wheel) then buy doing 360 / 12 = 30 we know eatch tooth is 30 degres
so if we are at tooth 10 we are at 300degres. now if we want to add a spark at 30deg before tdc we do 360 - 28 so the spark should happen @332 deegres.
now we know that each toth is 30deg so 332 is 11 teeth plus some time. now what i dont know is how to get exactly the 332 deg from crankshaft reading also how to handle the full engine cycle aka 720 degress rotation and how to add the TDC angle offset becouse tdc could be tooth 4 for example