On 07/03/2011 19:14, PICdude wrote: > For four cylinders you will > get 266.67 Hz at 8000 rpm. or a more believable 26.7 Hz at 800rpm. --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .