Arduino Real Time Clock Bargain Of The Century!!!!
The DS-3231 "The Industry's most accurate RTC" by Maxim Semiconductor has an accuracy of +-1 min per year.
www.Macetech.com has some of their DS3231 "ChronoDots" with a manufacturing defect ...
the headers were installed upside down. They reduced the price by 47% to only $7.99 (US).
(I told them to de-solder the headers and bought two of them - they even included the lithium batteries)
For those who use the I2C DS-1307 which has an accuracy of +-2 minutes per month this is a real bargin
because you pay $20 from Sparkfun for their DS-1307 board and only $5 from Futurlec.
The I2C wire software that works for the DS-1307 should work for the DS-3231 with no modifications.
Get them before they run out of stock!
Link: Macetech
Thanks for the mention, Andy...please note that we won't be desoldering any more headers on the discounted ChronoDots in the future, they're sold as-is from this point.
Let me know if you need any hints getting these running. Typically, any code that uses the DS1307 will work with the DS3231.
I just replaced my DS-1307 and dropped the ChronoDot in my development system and it works with no modifications whatsoever! The I2C address of 0x68 (104 dec) is the same.
BTW ... Digikey has the DS-3231 SO16 chip for ~$7 and the battery for about $1 and this does
not include the printed circuit board ... what a steal.