On Sun, Jan 4, 2009 at 11:01 AM, Olin Lathrop wrote: > 4e fte wrote: >> considering rpm ignition signal to be a square wave (in the case of a >> toyota ignition system at least), could someone please guide me as to >> how I could count the rpm when properly interfaced to a 16F84A. > > No, that would be silly. Return the 16F84A before the museum finds it > missing, and get a real PIC with a CCP module. A CCP module in capture mode > is the best thing for doing what you want. The 16F88 and 16F648A both have > CCP modules, various other possibly useful peripherals, come in the same > footprint, and cost less than the 16F84A. > > Since this is apparently a one-off hobby project, I wouldn't even bother > with a PIC 16 at all. Unless you really need the space, get a handful of > 18F2620 and use them for this project and future ones. Think of the 12 and > 14 bit cores as being for high volume projects. About their only advantage > for hobbyists is if a small package is really required, but that's rare. > 18F2620 - $5 16F886 - $2 For simple one off projects, I'd rather buy a handful of 886s. 10 x 16F886 = $20 10 x 18F2620 = $50 Starts adding up - but only if you're a student and on a budget like I am. -- solarwind -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist