Hello Jinx & PIC.ers, >Date: Mon, 24 May 2004 18:45:46 +1200 >From: Jinx >Subject: Re: [PIC:] Timing intervals (in the range of minutes) > >> This actually helps me out more. I can treat every interrupt as >> a 15 second interval...4 interrupts would be a minute. :) > >If you re-load TMR0H with 27d (1Bh) you'd get 15.007744 >seconds - pretty close for minimal effort > >> >which is 4.194304s @ 4MHz internal clock (16MHz crystal) > >Here's a funny thing....just after that reply I was looking through a >bag of scavenged crystals for an application with odd timing and >actually found a 4194.304kHz. Now wondering what the heck it >would have been made for > 2 ^ 22 = 4 194 304 Using this xtal as all my designs do, lets me run a timer-tick isr at tmr0 overflows every 976 usec. It also conveniently divides down to *exactly* 1 pulse/sec. so apps. that need real-time precision can have it without arithmetic hoola-hoops. Now class, who can tell us what hoola-hoops were? best regards, John email from the desk of John Sanderson. JS Controls, PO Box 1887, Boksburg 1460, Rep. of S. Africa. Tel/Fax 011 893 4154, Cell 082 741 6275, web http://www.jscontrols.co.za Manufacturer & purveyor of laboratory force testing apparatus & related products & services. -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu