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Re: TinyRTC I2C Module DS1307 + AT24C32N

Posted: Fri Oct 12, 2018 7:11 am
by philwilkinson40
similar but not the same!
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Re: TinyRTC I2C Module DS1307 + AT24C32N

Posted: Fri Oct 12, 2018 7:58 am
by mcauser
Judging from these schematics, another thing you could try testing continuity between the battery terminals and the DS1307 IC
https://robotdyn.com/pub/media/0G-00005 ... ATALOG.pdf

Pin 3 Vbat
Pin 4 GND

Re: TinyRTC I2C Module DS1307 + AT24C32N

Posted: Sun Oct 14, 2018 8:49 am
by philwilkinson40
continuity appeared fine.

With a more detailed search around I found others complaining of similar problems. In common with the author of the link, the D1 diode was defective on both my shields. I removed the diode and resistor R5 completely and the RTC module now works.
As the IC appears to be ok with the maximum output of the CR1220 I have no idea what the purpose of the diode and resistor are in the circuit.

Anyway, the issue was entirely hardware related so apologies to bother the author of this excellent driver!! Thanks Mike :D

Re: bizarre circuit design

Posted: Tue Oct 16, 2018 5:59 pm
by pythoncoder
I guess the diode protects against a reverse-fitted battery. What a revolting way to do it. :!:

R5 only makes sense if they have shares in a battery manufacturer.