AVR-Chat

<snip>
> >soil temperature and soil moisture will be very slow change 
variables
> >so even with a time stamp, it would be a valid concept.
> 
> Actually no, the idea as stated was that the signal started at one 
value 
> and went in a monotonic fashion to another (no up and downs) and 
therefor 
> the total number of samples could be computed in advance even if 
the time 
> span is not known.  True, but it doesn't work for your inputs.
> The extension suggested (basically a difference encoding) would 
work for 
> some of your inputs, but not for light

I think we are agreeing that somethings like soil temperature, that 
will take hours to change under normal circumstances can be run thru 
a differential calculation and only when the answer is not zero, 
would it record the data.

The only fast change I can forsee is watering.  When one waters a 
plant, the soil temperature changes rapidly and with large variations 
from the previous point.



> >as for light, this brings up an interesting study and probably one
> >that will gain students interests and that is comparing the growth
> >rate of identical plants in varying conditions.
> >
> >Will a tomato plant for instance, grow faster with 4 hours of 
direct
> >sun or with 8 hours of the the same total light intensity ?
> 
> More interestingly what effect is there if the 4 hours is 
distributed in 
> say 5 minute segments (ie 5 on 5 off)?  Is that any different from 
4 
> on/4off at 8 at 50%.


ah, the nature of research...  who knows what the answer will be.  
Seems to be a simple project though.

Dave