Following on from this threadhttp://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1163418637/0
I was investigating how to run a 328 from as simple mobile supply as possible.
According to spec, 4.5v (from 3 AAs) should be too low for 16Mhz operation, but my project "works" (I put it together before discovering this limitation!).
So I've just been doing a little experiment - basically I've been letting the batteries run flat to see when in conks out.
Last night it was down to 3.4v and still going strong - which should be WAY out of spec on the speed grade!
Unfortunately I forgot to turn it off when I went to bed and at some point it passed the threshold. But I got about 3 days continuous use which is not bad at all, and perfect for the application.
Obviously this is a statictical sample of one, but it's got me wondering if a 4.5v battery pack is actually a viable power source in the real world...?
What is the actual effect of running too low? Does the timing just become unreliable (which s not an issue in this case), or is there a more serious consequence?