On 6/11/08, Matthew Miller wrote: > On Wed, Jun 11, 2008 at 10:42:24PM -0400, M. Adam Davis wrote: > > Better designed internal oscillator, less sensitive to temperature and > > voltage change (perhaps temperature compensated?). > > > > Don't count on it for RS-232 and other timing applications if you plan > > to run it to its extremes in temperature or voltage - it can vary as > > much as +/-3.2% or so ( see figures 18-39 to 18-42 for graphs) which > > is greater than the 2.5% I usually restrict myself to when talking > > about RS-232 acceptable clock error. > > > > Still, if you drive it with a reasonable voltage, and stay within a > > restricted temperature range, then it should work reasonably well (ie, > > +/- ~1%). > > Right now at 5V and room temp. 9600 buad and 1 minute measurements work well > with the 16F689. I'll soon see how that 1 minute timer works in full sun > shine and using 3AA batteries. Data transmission over serial can occur > in-doors, but hopefully the 1 minute interval won't change too much. My experience with 16F676 and internal oscillator at 115200 is not very good. How many boards have you tested and on how many computers ? Sice then I'm not using only zero error crystals for communications and believe me it worth. Vasile -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist