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6 years ago.
LPC1768 RTC not working properly with battery backup.
I have two LPC1768 modules and neither will keep the time with a battery, CR2032, to back up the clock. One resets the seconds to 0 while the other seems to startup with some random value, sometimes negative when powered on, with or without the battery. Both seem to work OK (haven't checked the accuracy) when set as long as powered on. Has anyone seen these problems? Any ideas as to what to try? My units don't have the diode that one post suggests removing. Anyone added an external RTC to LPC1768? Thanks.