Chad, > Are you following the procedures in App Note 504 to ensure you do >not read during a register update? Well, I never read that App-Note before now. Therefore, I can't truthfully say that I abided by all of what's listed in it. I'm currently dotting the `I's' and crossing the `T's' with respect to 504. Ill let you know what the results are! Thanks for the information... Thanks, Eric --- In , Chad Russel <chadrussel@y...> wrote: > Are you following the procedures in App Note 504 to ensure you do not > read during a register update? > > Chad > > --- Phil <phil1960us@y...> wrote: > > > > > its always a good idea. does the PIC have a bypass cap? I'd try > > putting one on each IC (not just the whole board). it may not solve > > the problem but is fairly cheap and easy. > > > > you might also check the chip errata if you haven't already. > > > > --- In , "pondindustrial" > > <pondindustrial@y...> > > wrote: > > > > > > No bypass caps at the RTC, but yes across the supply entering the > > > development board... > > > > > > Are you thinking a cap at the RTC power pins would solve it? > > > > > > > > > > > > > > > > > > --- In , "Phil" <phil1960us@y...> wrote: > > > > > > > > got bypass caps? > > > > > > > > --- In , "pondindustrial" > > > <pondindustrial@y...> > > > > wrote: > > > > > > > > > > Hi group, > > > > > > > > > > I recently placed a DS1307 RTC on a breadboard and wired it to > > a > > > > > PIC16F877 and started reading data. I was displaying this data > > on > > > a > > > > > PC through serial, via VB. Every once in a while (couple of > > > minutes) > > > > > I would read a mess for the date and time, but ONLY for the > > date > > > and > > > > > time values, hence, the delimiters (/: etc.) displayed as > > > expected, > > > > > no corruption. > > > > > > > > > > At the time, I attributed the problem to the rats nest of comm. > > > > > wires > > > > > strung across the breadboard and didn't give it much further > > > thought, > > > > > especially since the delimiters continued to display properly > > > (which > > > > > are added in the PIC of course) and only the RTC data did not, > > > i.e.: > > > > > garbage in, garbage out! Well, a few days ago I wired in a 4x20 > > > > > LCD > > > > > and started displaying the data on it instead of the PC, I > > still > > > got > > > > > the garbage, as expected. I then soldered the RTC to the PIC > > > > > development board I'm using and made sure all communication > > wires > > > > > were short and isolated as best possible between the RTC and > > PIC, > > > > > I'll be dammed, I'm still displaying the intermittent garbage. > > > > > > > > > > Any clues where the source is, IMO it has to be coming from the > > > > > RTC > > > > > correct? But why, and how can I possibly get rid of it? > > > > > > > > > > As a footnote, I also added a separate routine immediately > > > following > > > > > the date/time routine to display an incrementing variable on a > > > > > different line on the LCD, the incrementing variable never > > > displays > > > > > corrupted, only the RTC data > > > > > > > > > > Thanks in anticipation! > > > > > Eric > > > > > > > > ===== > My software has no bugs, only undocumented features. > > __________________________________________________ > |