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Old 08-19-13, 09:32 PM   #25
AC_Hacker
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Quote:
Originally Posted by Acuario View Post
It's a totally custom controller. The individual machine controller uses a pic 16F628A built on a pcb that I designed and the main controller has a 16F877 built on a pic board I bought off ebay.
It uses a PIC..? I'm not so familiar with that, it is somehow comparable to the Arduino?

Also, I'm curious about how you contend with defrost? I would guess that you have a thermistor situated in the coils somewhere near the place where you have observed frost forming, and when it gets to some level that would indicate that frost is actually forming, your PIC executes a routine wherein it changes the state of the reversing valve, thus effectively reversing the positions of evaporator and condenser, and directs hot refrigerant into the frosted evaporator for a duration of maybe a minute, after which it restores the state of the reversing valve, and re-commences normal operation... did I get close?

Also, since my ASHP's mystery controller card is totally holding me up, could I persuade you to sell me one of your cards?

By the way, I did find someone who is working on a Panasonic mini-split and they posted some code HERE, possibly it could be useful to you in your quest to slay the Inverter Dragon.

Best,

-AC
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