home made heatpump

[WyrTwister]

Originally Posted by matic33

I only use it for heating. It could be used for cooling to but i have radiators installed. I use it for heating till outside temperature is about -5 then i start heating with pellets.

I have gree minisplit LOMO 70 indor unit: GWH24QE outdoor unit: K3DNB6G.

I get what I want from it. Water temperature is about 50 degrees which is enought for me.
I only have I problem with electronics outdoor unit wont work without indor unit.
So i had to connect indor controller. I placed intor heat exchange sensor at the end of condenser set room temperature to 30 degrees so that unit will not stop because of room temperature. When the water temperature get to 50 degrees i simply use thermostat to swich off power fro unit. It means that compressor work at full power all the time.

I am asking if there is some kind of comtroller to make uotdor unit work without indoor unit to get propre controls.

Matic

Are you speaking of degrees F or degrees C ?

God bless
Wyr

[Fionn]

Definitely C

[jeff5may]

Originally Posted by matic33

Thanks for answer
does anybody know how communication between indoor and outdoor unit work.

Nearly all of the newer units use proprietary serial comms. A very few of the units have classic low voltage control wires. A lot of the newer units use a power line interface much like power line ethernet adapters. This is the main reason they won't work if one of the units is connected backwards. Either the data is flipped, so that highs from one unit show up as lows to the other; or the data is carried on one line, and one unit is deaf to the other.

Figuring out what type of data transport mechanism your unit uses and the control codes used to do what mode or function becomes an exercise in computer science. If you're a computer scientist, go for it. Having a working indoor unit, a remote control, or both on hand would make the project much easier. If not, you'd better learn a lot about computer science and have lots of time to spend on the task. Once the operation is decoded, a "fake indoor unit" module would have to be made to keep the outdoor unit under control.

Then again, maybe you could call Gree and find out if they make some sort of "master control" that does what you are looking for.

[NiHaoMike]

Not sure which Gree you have but I remember reading that the ones with Wifi use a high frequency interconnect similar to DSL. Maybe it's even one of the features of the Qualcomm chip that handles all the wireless and whatnot.

[AC_Hacker]

Originally Posted by matic33

Thanks for answer...

In spring I will see if i can hack signal.
It is a long time since i was doing anything on electronics and it may be interesting.

I wish you good luck with this project. Being able to crack the communication code on minisplits is quite a bit more challenging than many people think.

Acquario has attempted this, and learned quite a lot.

For one, the serial protocol seems to conform to the RS-232 standard.

Further, it looks like the controller does not just send a simple ON or OFF, rather it sends a whole frame of data, regarding the various aspects of operating states. The state, and the ON or OFF is within that frame.

I'm not a serial communications expert at all, and have very much to learn.

Please keep us posted on your progress. If the communication scheme with a minisplit can be fully understood, it will open up very many new possibilities.

You might search EcoRenovator for "Acquario" to see if you can find any existing info. You also might try using EcoRenovator email, to contact him directly.

Good Luck

-AC_Hacker

[Xringer]

Here's the FCC info on the RF link.. https://fccid.io/2ADAP-SAA1FB1F

[NiHaoMike]

That's for the remote, which appears to use BLE. But it's the indoor unit that has the BLE chip, which he wants to get rid of. The outdoor unit communicates with the indoor unit over some unknown protocol.

I think the next step is to take a picture of the outdoor unit board where the indoor unit connects so we can see the coupling transformer or optoisolators and have an idea where to start. Hoping it's optoisolators (low frequency) since a high frequency link is going to be hard to reverse engineer even with a scope.