Re: MMIR X-10 Macro IR Module

[Marc_F_Hult <MFHult@xxxxxxxxxxxxxxxxxxxxx>]

On Fri, 21 Sep 2007 16:41:57 -0400, "Robert Green"
<ROBERT_GREEN1963@xxxxxxxxx> wrote in message
<Wa6dndmIqKpisWnbnZ2dnUVZ_tmhnZ2d@xxxxxxx>:

>If the HomeVision unit is put to any kind of temperature related-chore,
>it's a pretty good assumption that I'll use a look-up table instead of my
>bad math.

A 'look-up table' is conventionally a table that one looks up values in,
often to use as a starting point for interpolation.

More likely what you would want/have to do owing to programming limitations
is to set up 'events' defined by values. That's conceptually  a different
exercise.

This approach also works well in practice for many conventional HA tasks.

For example in our brick house, which takes forever to change temperatures
owing to the large thermal mass (heat capacity), these five 'events' cover
most of the HVAC need:

85F --> SummerNotHomeTooWarm
78F --> SummerAtHomeTooWarm

68F --> WinterAtHomeTooCold
60F --> WinterNotHomeTooCold
50F --> WinterTooColdEmergency

One can simply determine experimentally (by measurement) the binary output
of the ADC at these five temperatures with whatever temperature sensor you
choose (LM3*, thermistor. thermocouple, etc) and set the 'event' equal to
that byte value (assuming 8-bit ADC).

One can then (also) tweak the system as desired by circumstances by
changing the value of the constants without messing around with the rule
set (i.e., the control logic) which is where many errors creep in.

.. Marc
Marc_F_Hult
www.ECOntrol.org