Hello, I’ve been programming the Olimex P64 board for the last couple of weeks. I wondered if anyone else has seen significant drift with the RTC. At first I thought my PIT routine was mucking up, but after using the PIT to instrument the RTC, I found that the RTC clock wasn’t the prescribed 32768Hz. Now, I realize there is no watch crystal and therefore it’s not going to be greatly accurate. However, are there any suggestions on making it more accurate, so I can use it for an RTC?
On device init I measure the RTC clock by setting it to trigger at 4000 cycles, then I use the PIT to measure how many microseconds elapse in that time. Right now I’m measuring the RTC clock source at 33480Hz. Is this perhaps due to the wrong/bad components in the SCK RC circuit? I would assume that if they went to the trouble to put an RTC in the chip, that it could be accurate.
Thanks,
–Perry