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Topic: DS1307 reading time (Read 1 time) previous topic - next topic


I use this https://github.com/davidhbrown/RealTimeClockDS1307 library and am very happy with it, though I'm not so happy with the accuracy of the DS1307 (mine looses 7.6 seconds per day but have found a clunk way to improve it).

Yeah, I've mucked around with a bunch of them, and that's the one I eventually settled on as well.  The DS1307 library that Adafruit uses (forked from JeeLabs) is a decent start, but I seem to remember running into limitations fairly quickly.  IIRC the time setting code was weird?  It's been a while.

The DS3231 is nice and relatively straightforward plugin replacement for the 1307, but depending on your budget, the 1307 and supporting crystal/battery/etc can be had for under $2.  If you're designing a new PCB, swapping a TH 1307 for a SMD 3231 is no big deal, but if you need to adapt it to protoboard and have to buy a $15 Chronodot or similar, the price differential starts to add up.  The 1307 is accurate enough for most applications.  Within reason.


Hmmm, good to know.  I'm looking at making a watch so it kinda needs to be pretty accurate
Accelerate to 88 miles per hour.


By the time you buy that hardware and get the code to set/reset it it is cheaper to do a GPS... the time signal only needs 1 or 2 sats... works for me...

I would love to have GPS accuracy in my clocks but they don't pick-up a signal in the house. I even have a problem picking up MSF radio time signal in some places.

If you have electric service inside the house then you have a bedrock-solid pulse source that a Hall sensor should be able to pick up.
I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.


I've never done anything with hall effect sensors. I don't understand them.  What do they do?
Accelerate to 88 miles per hour.


I've never done anything with hall effect sensors. I don't understand them.  What do they do?

Sense magnets. You supply power and ground, they provide a signal. Some of them are just high/low when they see any magnetic field, some are pole specific, others are one pole on until it sees the other pole.

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