AVR-Chat

--- In AVR-Chat@yahoogroups.com, Robert Adsett <subscriptions@a...> 
wrote:
> At 09:40 PM 7/15/04 +0000, you wrote:
> >--- In AVR-Chat@yahoogroups.com, Robert Adsett <subscriptions@a...>
> >wrote:
> > > Speaking of small amounts of data, have you checked to see how 
your
> > > analysis program responds to the amount of data you've been 
talking
> >about yet?
> >
> >No.
> >
> >The most likely candidates will be a spreadsheet or an Access
> >database.
> >The most common use will be to print a full graph and then sections
> >of interesting parts of it.
> 
> Definitely check real soon now.  I strongly suspect this will limit 
your 
> data collection more than your ability to store it locally as you 
collect 
> it. 

On my CNC computer in the basement, the Compac 166 with 64 meg of 
memory. Win98se

Excel shows 65,536 lines and reports that 32,000 points is the limit 
for a single column for a chart.

It takes about 3 seconds to get a graph of the 32,000 points.

With a small amount of mathematical reduction, that offers a 
highlight  of the points of interest.

A single point reading once a minute is 10,080 readings per week.  
That means that a reading once each 10 seconds would be 60,480 points 
and would fit in one spreadsheet column.

I did a little more on Excel.  12 columns of 24,000 readings per 
column and it takes almost a minute to render the graph.

Since it is not possible to print a graph of any value with that many 
points, mathematical reduction will be reguired.

But, hourly and daily totals and averages will be easily done and 
those graphs are printable if the massive data points are available 
for reference.

This means the brute force method of 'just log everything all the 
time' could be done, but with something on the order of 130,000 
readings per week including a time stamp. All the points can be 3 
digit integers including the time. 

I'm thinking that means the brute force reading will eclipse the 
limit of a ram or eeprom.

But, from this information, this does not seem to be a stop on the 
project.

Finding time to learn C is ! 

Dave