AVR-Chat

another question, 

If one pulls in data strings, say, reads 40 sensors and then wants to
log them.

does the dataFlash on the Butterfly allow incremental writes or does
it need a block write ?

Also, if the data is strictly temperature from an LM34 (or some such)
I assume the temperature could be logged as 56.78 or 5678 ?

then if each system scan were preceeded with the time, then points,
there would not be any need for actual point references, the final
shpreadsheet could add the header and fill in the columns.

so, each line might be 

12:00:01 5678 5688 5777 (and so on)
12:01:01 5677 5692 5888 (and so on)

and be repeated for all 40 points.

would that be written after each scan, or would a whole memory block
have to be written ?

how do I calculate how much memory would be used for the on-board
dataFlash ?  


= = = = =



Also, the timing.  Timing is not critical.  on a micro with a crystal,
the internal timing can be accurate to better than a minute a week. so
a RTC might not be required.

ideally, one would pull the DC card and install a new one, press the
START button and a single line of day, date, time and whatever would
be the first line of the file, or even the file name ?

Anyone know just how accurate the timing is on a Butterfly ?  can I
get a week or more from an interanl timer ?

Dave