Controlling a DC inverter machine

[grayhawk]

Originally Posted by AC_Hacker

Well grayhawk,

You certainly have my attention.

I for one am very glad that you are posting your progress in such useful detail.

What kind of USB based logic analyzer are you using? I saw several on ebay that I thought were interesting... some very inexpensive ones, too and they looked to be easily offer the bandwidth I would need for a project that is not unrelated to your project.

Keep up the good work!

Best,

-AC

The small analyzer I'm using is the 8 bit Saleae Logic 1.1.15. But another one my brother uses is the Open Bench Logic Sniffer. Sparkfun.com has both of them I believe. I'd like to write a protocol analyzer for this one, once I understand the data stream well enough.

For this kind of stuff, it doesn't need to be super fast.

GH

[grayhawk]

I have found the source code for an example protocol analyzer, to use as a starting point. This one is for the Sony SIRC protocol, but I'll translate it ovet to the 'space' or pulse distance encoding. Maybe a day to do that.

So I should have some real results soon.

In the meantime, I posted on the Finnish web forum a couple of questions as to the Sanyo protocol & to see if anyone knew what YMGI is using for sure. Near as I can tell, YMGI is just an empty building, with a bunch of scripts & bots running.

GH

[grayhawk]

A minor surprise.
I received the little IR receiver from SparkFun & started looking at the actual YMGI remote signals.

They are different from the Sanyo wired remote. So I will proceed with the YMGI remote as the 'standard'. They still appear to be 'space' or pulse distance coded; but there are much fewer bits. That's OK, makes it easier to implement.

bc

[grayhawk]

I didn't have a lot of time to work on this today as we were working on our long distance wireless links; but I did capture a few traces for various keys pressed. The first group of bits is always 35 bits long.

This image shows 4 packets captured for 4 different keys pressed.



In tabular form & easier to read:

First 35 bits of scans for YMGI heat pump:

1: 10010010000100000000011110111010010 don't know which button was pressed
2: 10011010000100000000011110111010010 fan button was pressed
3: 10011010010100000000011110011010010 plus button was pressed
4: 10011010100100000000011110011010010 minus button was pressed

GH

[Acuario]

It's been a while since I posted about my progress with controlling the Daikin; the summer has been hot and busy so I've had little time to play. I did start developing the control system with a PIC development board but soon ran out of space (it only has a very small memory) so I'm now going to port it to a Raspberry Pi - watch this space!

I ended up using the pic board for my greenhouse project - see elsewhere on this forum.

Acuario

[wauzestyle]

Originally Posted by Acuario

Here it is. The device that interfaces from the TTL logic to the power leads is the HF6 3EB - probably a custom device as I can't find any reference to it anywhere. The rest is just basic RS232 to TTL level conversion stuff.

The CUT is where I break the comms from the internal unit to be able to send my own commands.

The CLK signal from the HF6 doesn't appear to be doing much as the data isn't synchronised to it in any way. It runs at 100Hz. I may be wrong but for the moment I'm not worrying about it.

Nigel

Hello Acuario,

thanks for all the information about the daiking airco communication. I whas wondering if you get all this working now?

i want to control a daikin outdoorunit (standalone) with this serial interface. this communication goes treu one extra wire to the indoor unit. Do you have any suggestions to control only the outdoor unit without the indoor unit electrical connected?

love youre posts!

gr jeffrey

ps iam not able to send you a message directly/

[Acuario]

That is pretty much what I was doing - I used my pc to control the external machine. The internal bits were still connected as it provided me the interface from the rs232 to the external box - this goes via the (unknown what it is exacly) HF6.

I bought a second hand Daikin control board from ebay that has a HF6 on it for when I get around to building my controller. If you trace the wiring you'll find all 3 wires go to this device. I tried a simple hack using some opto-isolators to try to simulate the control circuit but no luck. Keep a look out for a board with a HF6 on it!

Sadly I've been somewhat busy with all sorts of other stuff and haven't had time to do anything with the Daikin. Hopefully soon...

[grayhawk]

Having the usual problem of too much to do with too little time to do it, I've opted for the easy way out to control the YMGI heat pump at my hangar.

I am just recording the IR commands fro the handheld remote for a few key commands, and then using a Raspberry PI small computer with IR transmitter to send them at the hangar. This can be done remotely over the internet.

I only have 4 commands in my configuration file for now:
OFF
HEAT_ON
COOL_ON
AUTO_ON

IN the event someone with some real knowledge reads this, does anyone know who builds the YMGI heat pump or what the complete command coding is (with checksum). It appears the command stream is about 64 bits long.

Also does anyone know if I can patch into the inside unit control board and drive the signal directly, so as to avoid the need for IR?

Thanks

[grayhawk]

Originally Posted by S-F

Xringer, if you aren't going to dig deeper like I said you're just going to have to trust me when I say that it's almost impossible to control a mini split with an IR blaster. Both AC and IR blaster manufacturers have been talking about this for years and to my knowledge no one has managed to get it to work.

I have a small computer (Raspberry Pi) with an IR transmitter, controlling a YMGI mini-split heat pump in my hangar 4 miles away. I can turn it on, shut it off over the internet,

More to come as I figure out more of the data coding.

[jeff5may]

grayhawk,

Looks to me as if YMGI is a partner of Hiseer international, formally known as:

Guangzhou Hiseer Air Conditioning Co., Ltd

They seem to be a chinese contract manufacturer who will build whatever (relatively smallish) number of predesigned units with your name on them. It looks like YMGI in America is basically a storefront/marketing headquarters for the USA market.

I perused the YMGI website, and found very little useful information. The good stuff is either not built yet (training, documentation, service & support) or behind a wall you have to apply to get past. My guess is there's not much on the other side of the wall, either.

This company seems to be the norm in the industry nowadays. You must be an authorized service dealer to reach anyone with expertise. Even then, an abnormally painful and thoroughly boring series of conversations must be made with the "wizard" to determine anything.

The "wizard" is careful not to disclose anything to you that would simplify the repair or troubleshooting process on your end. Board or unit level repair is usually prescribed, with plug-and-play results. Sometimes I feel as if the "wizard" has no clue what's wrong, so he just sends the whole unit. Of course, he wants the old one back to diagnose it at his bench.

The good news is that the unit is probably the "house that Jack built", i.e. someone elses' hand-me down parts from prior production runs. Hiseer grabs the guts from a "no longer available" unit line, reflashes the EEPROM with their control codes, and slaps a silkscreen on the unit. Presto! It's now a YMGI!

All you really have to do with these units is look into the guts to find out where they originated. The hardware is designed once, then recycled for as long as economical. As for control codes, source code, or a master program chart, this stuff stays inside the r & d department. It will pretty much need to be reverse engineered.