Thank you for the response. It matches the experience I've had with trying to get any information out of them.

I have most of the command string figured out. I just need to spend the time & capture enough different commands to figure out creation of the checksum at the end.

I finally have some time to go back to playing with the Daikin. Hopefully some progress soon.

On my trawling of the internet I came across this from Danfoss which is interesting for anyone looking to hack inverters:

Inverter-scroll-VRJ - Danfoss

and the manual for controlling the compressor:
http://www.danfoss.com/NR/rdonlyres/...al20111117.pdf

I've also now got my hands on a Panasonic unit so as and when the Daikin is cracked and I'm up for another challenge.....

Acuario

wow
http://variablespeed.danfoss.com/NR/...lustration.jpg

15-75 hz speed range
internal oil injection
permanent magnet motor

My question is: how many wires does it have and can I hack it?

EDIT: On the first link cited above, have a look at the related content document "further technical information". This is how they are making mini-splits nowadays. Main difference: no electronic expansion or check valves indoors. Scary...

Here are some solutions.

cant post here

https://harizanov.com/2012/02/defrost/

https://harizanov.com/2013/05/re-vam...er-controller/

remote control hach

Acuario, I tried both of those links, and they do not appear to be valid URLs

Do they still work from your location??

-AC

Nope, look like they have gone :-(

There are quite a few hacks around simulating remote controls now. Search for IR Blaster. Mostly are for TV's and audio but HVAC ones are appearing too. There are also a number of mini-splits appearing with WiFi connectivity - hope your firewall is working :-)

None yet though are 'pure' hacks to hook in and control the machines directly.

The Holy Grail

-AC

After much deliberation I have decided to abandon my efforts to build a controller for an inverter machine.

I achieved my initial goal which was to decode the protocol of a Daikin machine and control it from a PC. It was never installed but I did eventually decode sufficient of the protocol to be able to select the mode, start and stop the external unit and keep it running and monitor various parameters that the machine was sending.

There are several reasons for this which I will explain.
It appears that every manufacturer has their own protocol between internal and external units. I hacked into the Daikin, a Panasonic and a Samsung and each was substantially different. Also different series of machines will almost certainly also have variances. This being the case it is almost inevitable that whatever work I did to 'crack' one machine combination wouldn't work on another combination.

Anyone who wanted to use an inverter would, as such, need to start almost from the beginning. The investigations I have done may help if someone really wanted to try but without a fairly deep understanding of both electronics (for the required interfaces and subsequent controller design) and software engineering for both the protocol analysis and subsequent controller software then it would be a frustrating and disappointing venture.

There are many 'traditional' machines that have fairly basic control capabilities using relays to control valve, fan, compressor, heater available without suffering the frustrations of attempting to use an inverter machine. These provide their own interesting challenges without adding the complexities of multi-tasking operating systems and decoding unknown protocols. These machines, although not the most efficient, should provide sufficient challenge for most people for the foreseeable future.

I'm continuing with my design for a universal heat pump controller using a typical on/off machine and will provide more details in a different thread. As winter is now approaching I'll hopefully be able to refine the defrost detect and defrost a bit more - I'm trying different methods such as differential air pressure and temperature at the moment.

If anyone feels up to the challenge and needs any pointers on inverter control then I'll be happy to let them know what I discovered.

Possibly, in some future, someone will design a universal controller but I think they will need to go to the extreme of controlling the individual items with their own controller rather than hacking into and using what exists.

There are other approaches for the die hard such as maybe using the combination of indoor and outdoor units but with the outdoor unit connected to a heat exchanger rather than the indoor unit. This would involve retaining all of the electronics of the indoor unit and controlling it with, maybe, an IR buster app. I leave it to the hackers imagination....

Acuario

The same thing happened when AC and I got the general purpose controller thread going. There is really no such thing as a standard configuration. Everyone has different equipment and goals, and it is very difficult to get everyone on the same page. What we ended up with was half a dozen rigs, each tailored to different configurations. In general, we failed to make a generic rig that anyone can use on what have you, but I still consider the endeavor relatively successful. Many of us produced working systems during the thread.

Since then, I have been made aware of the fact that there are generic control systems available for cheap on the market. I have purchased a few of them, and they do an excellent job for the price. I believe one of them was around 50 dollars, and the other was even less. The brand I bought is Qunda. They also make universal remote controls (go figure).

Yes you are correct, everyone has their own goals. The problem with the inverter is that the control system is so complex that the effort/reward for the 'community' is too high and I don't think it would ever be used other than as an interesting talking point.

The generic controllers are great if you just want to connect up and run with whatever you have built, I have one running on a system with under floor heating and it seems to work fine. The downside is you have no control or possibility of extending/experimenting etc. but as a basic quick cheap solution they seem to work fine.

I've now got my own 'home made' controller up and running so for anyone who wants that level of control complete with web interface then that is also an option. I'll publish it in a separate thread.