Hi to all, There is some thing I do not clearly understand about VW battle engine. th= e=20 rotor has 4 magnets on it and the board has 1 hall effect sensor with none latch version so each magnet will control ea= ch=20 cylinder. lets say 8000 engine RPM I divide by 60 to get the frequency 8000/60=3D133.33 since 4 pulses is one= =20 revolution x4 I get 533.33.=20 I have been told 133.33 is my frequency but the way I calculate 133.33 is e= ach=20 cylinder not looking at the hall sensor. it sounds like 133.33x4 should be 533.33 not 133.33 since 1 revolution is 4= =20 pulses?=20 my question is witch one is correct 133.33 or 533.33 my understanding is it should be 533.33 thanks Andre =20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .