Quote:
Originally Posted by AC_Hacker
Yeah, this sounds great. One problem with that approach that I'm wrestling with is, assuming that the TEST KEY is a toggle (ON & OFF),
then how will the system know what state the heat pump is in? I mean, if the process skips a beat, then the unit will go OFF when heat is required, and go ON when too much heat has been reached.
Best,
-AC
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I've been thinking about the test button, and what the control table enables you to do.?.
• Once push : Ignore Communication error.
• Twice push : Comp. ON, / Outdoor Fan ON / Reversing Valve Coil ON(only Heating Model) / Crank Case heater Coil ON(only Heating Model)
• 3 Times push : Comp. ON, Outdoor Fan ON / Reversing Valve Coil OFF(only Heating Model) / Crank Case Heater Coil OFF(only Heating Model)
• 4 Times push : Same
• 5 Times push : Error LED(Red) ON
• 6 Times push : Comp OFF, Outdoor FAN OFF
• 7 Times push : Reset
The diagram shows where you need to attach a logic zero (ground).
Each button press puts a Ground pulse (0 Volts) into R58, that feeds Pin 1 of the micro controller.
I would use an Opto Isolator, to keep outside power supplies, and static voltages off Pin 1.
By experimenting with the button, you should be able to tell, if there is a time-out for a test mode run. (My guess is No Time-out).
Leave it in heating mode for hours.. If it stays, you don't have to re-command it..
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Next item, is there a
standard 'command' time-delay? After you push twice (heating mode),
can you just wait 5 seconds and push it twice again? And stay in heating mode??
If there is a few seconds of command time-delay, then control will be easier.
The nice part about using a Micro controller (like the CAI board),
it can generate the required number of pulses, very accurately.
If the programming of the pulse width & spacing is done right,
(to simulate a finger on the button)
there will be no need for feed-back, you can just assume it's in the requested mode.
If it did fail to be in the mode requested, the pulse program needs tweaking.
This is the perfect app for the CAI board! It's temperature inputs, used with
a TTL input from a thermostat would be super easy to implement.