Can anyone suggest a RTC IC which supports I2C communication,battery backup input, and alarm?. i.e with combined features of DS1307(which don't have alarm) and DS1337(which don't have battery backup).
Have you looked at the DS3231? Probably only available in SMD but it’s not that hard to solder. Or buy a module on Ebay, I have a couple and they work great.
DS3231/2/4, M41T00,MAX3231,MAX6916, PCF2127,PCF2129A
EDIT: Oh DIP, don't know if these are available in DIP.
Not sure I know of any DIP types with those features.
If you want to avoid soldering SMT, there are breakout boards available, e.g. the Chonodot for the Maxim Integrated DS3231.
I sell a few breakout boards for the Microchip MCP79411/12, link below.
I bought an MCP79410 module from an unnamed person… and it works a treat, Easy to use with the code provided by the forum member that supplied the module… Jack… somebody…
Highly accurate with a temperature sensor as the oscillator can be digitally compensated for changes in ambient temperature…
I was recently thinking about adding a temperature sensor to the RTC board, that would be real convenient for a temperature compensation algorithm. Have you already done this?
And thanks for the props
Yeah, I use a DHT22, more ! fer the buck… Not that it’s really required as I am not comfortable in temperatures that make the clock inaccurate… Great function tho. easily implemented Too.
Microchip's SMT temperature sensors look pretty interesting. Many are I2C devices. That would tend to keep code size down, not needing another protocol.
In my case RH data is as important as temperature... The clock module replaced a 'difficult' GPS receiver using the Time Library... It would lose about 10 seconds when synced every 24 hours and it needed a nearly clear view of the sky... worked by my window.. Mostly but when I moved it to my bedside it was poor at best... Cheaper to replicate as well, as good GPS devices are still $16.++ on the 'bay..
Thanks you all for your suggestions :). I wish there was an IC which has the features I mentioned. :~