[time-nuts] Lady Heather numbers

Achim Vollhardt avollhar at physik.uzh.ch
Fri Mar 8 11:05:38 EST 2013

Hi Peter,

first of all, LH can only 'control' temperature, if it has a hand to do 
so.. meaning it can steer the RTS line of the RS232 to control a small 
fan via PWM. Actually, it could also heat (by putting there a heating 
element) but I haven't seen anybody doing it yet. If there is no heater, 
heating is done by letting Thunderbolt warm up on its own.

So if the measured temperature is above the setpoint, the fan will be 
switched on, otherwise not. Of course the controller is a much more 
sophisticated PID controller and the output is PWM so it can actually 
regulate the fan speed such, that a nice stable temperature can be 
achieved. I think you have to search this mailing list for all these 
infos, is has been discussed quite some times.

Keystrokes: These have to be found when checking the .cpp files in the 
leady heather package. Sorry, it has been a while for me .. I'll leave 
that up to you.


> I am not convinced the temperature control in mine is functional. For example,
> the temperature target seems to not do anything at all.  With the box insulated
> the internal temperature is around 46 C and nothing changes if I set that number
> to 40 or 50 C, it is still around that 46 plus or minus 1 or 2 C as the
> environment changes.
> What do you mean by having your fan steered by the LH temperature controller?
> As for the optimization, I can't find that key combination.  Is there anywhere a
> COMPLETE listing of all the key functions for the program?
> Peter

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