[lm-sensors] A better fan control program
paul at lshift.net
Wed Jun 28 14:13:40 CEST 2006
Mark M. Hoffman wrote:
> I skimmed through the blog entry and the earlier one which it references.
> In your first attempt you reinvented the 'P' part of a PID control loop.
> Don't give up! ;) There's a *ton* of info about PID controllers on the
> web. If you're still interested, you could start here:
Very interesting stuff, thanks!
My quick reading of this stuff indicates a possible problem. On my
system at least, I can only read the temperature in whole degrees;
lm-sensors returns a number in thousandths of a degree, but sadly the
last three digits are always zero. This means that our differentiation
of the temperature will be very crude, which could make it difficult to
build a functioning PID controller.
How can I find out the maximum safe operating temperature of my current
CPU? Since my first priority is something that works on my current
system, the only reason for me to pick this up again and explore in more
detail is if I can afford to slow the fan even when the system is flat
out, which means I need to know how fast I can run it.
 Paul Crowley
 LShift Ltd
  www.lshift.net
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