Eeprom

MichaelDeFalco

I have a critical application that I will need to store counts.
I cannot afford to lose the counted data if power is lost.
The counts will be in the thousands per day.
How many times can eeprom be written to?
Or do I need a ckt. to detect power drain & switch to battery back-up?

Thanks,

Mike

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M.D.

rixter

I believe you can generally write around 100,000 times to a typical EEPROM as used with the BASIC Stamp. I have made temperature recording projects that poll temperature and date/time and write to EEPROM write on a BS2 for later retrieval with Stamp DAQ. But the most I was writing was up to 4 times per hour. I think the trick may to have a socketed EEPROM that you can just replace when it gets "used up". I do not know how you can test for that inevitable time however.

Rick

Mike Green

EEPROMs generally can be written somewhere between 100,000 and 1,000,000 times before the location begins to "wear out". An easy solution for you would be to use a DS1307 real time clock with a backup battery. These have 56 bytes of RAM available for the user that are backed up by the battery. SparkFun has a breakout board that includes a crystal and battery and is essentially "ready to go" (www.sparkfun.com/commerce/product_info.php?products_id=99). This is an I2C device and is included on the Parallax Professional Development Board, so there is plenty of documentation and examples of its use.

MichaelDeFalco

Thanks Mr. Green - I looked at sparfun & parallax pro. dev. board - This could work!

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M.D.