Re: Data logging... how to.

Mich wrote: 
I'm in a little project, trying to tackle a few problems.

I need to measure a temperature, and store it for later readout.
I will be using an AVR for temp. reading, and doing some other stuff.
The temperature will need to be stored in hourly samples, with a runningtime
for about nearly a year.

In my idea i would be storing  hour-day-month-year-temp. I calculated that a
needed about 4 bytes for this, so for nearly a year, i'd be oke with 256Kx8,
which i prolly need to do external from the AVR.
Now, after the year, the data will be shifted continously , so there will
always be the latest data reading about 12 months back.

Questions:
- Am i going the right route with simply storing in hhddmmyytt, or am i
wasting ram space?
- Would i need to shift every time all 256Kbytes one adress down, and place
the latest value on top, or would a 'current pointer' do the job,  which
could be used in the MSB from the 4 bytes, which is prolly not used.

Any help appriciated.


Thankx,

Mich




Hi,

Here's what I did for storing a lot of sample data...

http://members.cox.net/berniekm/spydar.html

Basically, only store delta times. I needed to know the absolute time, so I do that with the program that reads the data from the unit.

Some of this may apply to you.

--
Luhan Monat: luhanis(at)yahoo(dot)com
http://members.cox.net/berniekm
"Any sufficiently advanced magick is
indistinguishable from technology."
.

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