AVR-Chat

At 08:14 PM 7/14/04 +0000, you wrote:
>But if the internal eeprom is similar to eeprom chips the limit is
>something on the order of 100,000 writes ?  That would allow three
>changes every day for the next --- 100 years ?   I would expect a
>change once or twice a week.

For things like sampling time I expect that would be true.  For data 
maybe/maybe not.

>I guess simplicity would be a key factor.  what is the easiest way to
>send the AVR the data and what is the easiest way to keep it thru a
>power loss.

The simplest method I have run into is to use FRAM. The write speed of 
SRAM, the non-volatile nature of EE and an endurance of something like 1e9 
cycles.  Ramtron now makes serial FRAMs in up to 256Kb (thats bits).


>Eventually, this will be connected to a memory card like a MMC or SD
>or CF, but I think one could not put program variables on that ?

Sure you could, then you could set up the sample schedule on an MMC and 
plug it in and record the collected data back to it.  You may want to save 
that complexity for a second iteration though.

>(realizing the trees have branches......)

Branches have twigs :)

Robert

" 'Freedom' has no meaning of itself.  There are always restrictions,
be they legal, genetic, or physical.  If you don't believe me, try to
chew a radio signal. "

                         Kelvin Throop, III