What's going on with these 314 byte SRKXXZS Mitsubishi Heavy IR codes?

[erraticallyefficient]

Hi, I have a SRKXXZS Mitsubishi Heavy Air Conditioner, with a RLA502A700L remote.

Unfortunately, I don't have an ESP8266 to collect the IR codes from the remote, however I do have a Broadlink RM4 mini.

The Broadlink RM4 is integrated with Home Assistant, and I've been running the learn commands with Node Red to collect the base64 output for each command. My intent here was to decode the bytes, then setup my own simple Node Red flow to build new ones based on the commands I want to send to the AC.

However, when I look at the collection of collected IR bytes, I'm not seeing the patterns I expect to see!

Given that this issue is possibly with the Broadlink, I didn't want to make an issue on this github. But also given that this github has the best resources I've seen so far...
https://github.com/crankyoldgit/IRremoteESP8266/wiki/Adding-support-for-a-new-AC-protocol etc
and you've already tackled some variants of the Mitsubishi Heavy, I thought you guys might have some idea what's going on here, and point me in the right direction!

Here is my collection of base64 commands, and my attempt to decide them into something meaningful. The colours are just to highlight patterns. (Or lack thereof!)
https://docs.google.com/spreadsheets/d/1F1DyulrEQg6hQ89R8tkbdz888bEwiuDR4h9Qynh81Cs/edit?usp=sharing

I collected these in sequence, and avoided changing any other settings on the remote between collections. The sequence of temp ups and downs were re-collected a day later, and I didn't reset the clock... However, as you can see, I'm getting a lot more bytes back than the complete examples you have of Mitsubishi heavy remotes, and there's no consistent value changes, even when I do something as simple as walking through the complete temperature range.

Does anyone have any tips on what I might be doing wrong, and/or how this could be decoded?

Thanks in advance!

[crankyoldgit]

Note sure how I can help with this, other than to offer constructive advice.
I'm not familiar with the Broadlink RM4 or it's Base64 encoding of an IR message. It doesn't immediately appear to be friendly for a user to be able to see what is going on with the underlying IR message.

• I think the de-Base64 data isn't a simple raw implementation, rather some Broadlink specific format. Do you know what structure it is in?
• Do you have a way of converting the Base64 data/Broadlink structure to our raw format?
• Do you have an Arduino board with an IR demodulator you could use?
• Looking at the spreadsheet, my guess is each hexadecimal byte pair is in fact a length of a "mark" and of a "space"
  e.g. two small values together (like 0E 0C) probably is a 0 bit, and one small & one larger value together (like 0E 26) is probably a 1 bit. That's just a guess. But maybe it will help you.

[crankyoldgit]

How did you go? Just following up.

[erraticallyefficient]

Hey @crankyoldgit !

I did end up successfully breaking it down into meaningful bytes, but when it came to then decoding what all of them meant, and then being able to assemble them back into meaningful commands... I ran out of time, and ended up sending pre-recorded base64 commands, with known states.

It's not really what I wanted, but it does seem to work reasonably well for my purposes.

Thanks for your help though. It was a good learning experience for me getting the decoding right!

[fusionstream]

@erraticallyefficient If you'd like to work on this with me lemme know. I almost died doing it the way you did with my mitsubishi non-heavy remote (only just found this) and I was only 80% done. The SRK has way way way more permutations. I will first be decoding the Broadlink Base_64 codes to pronto via irgen and then looking for patterns from there because using the pure broadlink base64 code makes it impossible to determine a pattern

[erraticallyefficient]

Hey @fusionstream, happy to share my analysis with you if you think it might help. I've noticed lately that the pre-recorded commands aren't ideal, and it would be great to have the option to actually build them... Here's where I got up to (more than a year ago) https://docs.google.com/spreadsheets/d/1EuBlM2E2GA1RXqkR003A-dTZbsN83f-X5WoSBk9whGA/edit?usp=sharing

I think the closest I got was "Sheet13", where I was guessing as to the intent of each byte. So far I'd isolated
mode | on/off | temp | intensity | fan

Let me know if this helps, or if you're already beyond this point!

[fusionstream]

Happy to have it! Thank you for sharing.

Especially this one:

So far I'd isolated
mode | on/off | temp | intensity | fan

Will help heaps!