I did some testing with a multimeter and it turns out, that the wires are connected the following way:
Controller → Control Box
P → Key1
R → D-TX
T → D-RX
5 → +5V
G → G
I hooked up my logic analyzer to the holes in the controller and I get different readings if I press the buttons. The problem is that I have no idea how to properly analyze any of that data. Which settings to use in the logic analyzer software ( I use Logic 2 by saleae) and how to decode them.
Any tips/ideas on that? 
I don’t use logic analysers much.
But Sigok software that I use (and presumably others) have “UART decoders” you can turn on.
See images.
I would initially see if you can figure out which wire of the Rx or tx is sending height data from the controller to the handset.
There should be quite a lot of data changing on this wire, as it’s sending data to update the screen. I think it will be on the “R” pin.
Once you’ve confirmed you’ve got UART codes, you’re into decoding stage (which again I don’t have much experience with).
You probably want to decide soon if you’re going down a Home Assistant+ ESPHome route, and get ready for that.
You can also start decoding messages with the ESPHome UART debugger.
And then I’d also start a thread on the ESPHome Discord and cross your fingers that @ssieb might help you out. Refer to Desky and this thread etc.
That’s where the real guru’s are active;) There will be a lot of experience over there with decoding and also the next step after that, which could be building a custom component.
I can help you a bit over there over too.
Decode UART
This guy seems to have the same desk.
I don’t seem to have access to that discord channel. Is it on the esphome discord?
Edit: Nevermind, I joined the discord. Thanks for mentioning me!
I got the sigrok pulseview software working. My main problem is knowing which parts of the data are corresponding with the button presses because there is a constant data flow even if no button is pressed and the LED Display is off. And I couldn’t find a timestamp function to start and stop, when I press a button 
One thing that might be worth checking (and again with me not knowing much about these things) is if your analyser needs to be grounded properly.
I know I had lots of noise coming through when I was reading data on my esp32 without correct grounding.
There are two kinds of these splitters and unfortunately, they look identical and they are often not described correctly. I was looking for this kind that lets you run 2 100Mb connections over a single wire, but once I instead received the kind that duplicates all wires on both sides. So they do exist if you can find them.
Any luck in connecting this desk to Home Assistant? I have the same desk controller and would love to integrate it in Home Assistant
Any updates here ? I have the same desk controller!
Hey everyone, thanks for your interest! Unfortunately, I couldn‘t figure out the wiring of the desk and I don‘t have the time to investigate any further.
You‘re best bet is to probably join the ESPHome Discord and ask around for help. There‘s a lot of smart people there that could potentially help you out.
Best of luck!
& let me know, if you were able to figure it out.
I was able to capture UART data with ESPHome, but don’t know how to decode/use it. Maybe @ssieb can help if I share the captured UART data ?
Thanks!!
Possibly. Create a thread on the esphome Discord off-topic channel.
It seems like I also do have the same Controller. Could some provide a pin diagram so I can also connect it up to a ESP8266?
Have you gotten anywhere with this?
A key reason why you didn’t get much luck with the RJ45 splitter is because this desk’s controller actually uses RJ50 - note how there’s 10 pins in the RJ connector (and 10 labeled pins on the board too!).
For some reason your motor controller also seems to have a B and a D UART channel (B-TX, B-RX, and D-RX and D-TX). Key 1 and Key 2 most likely connect to direct keys on the control panel (e.g. Memory button).
I’m in a similar conundrum, my desk uses a JSM-2.1-0.3W motor controller, which also employs an RJ50 jack instead of RJ45. I’ve only pulled the hand controller apart as of now, but it only shows a handful of pins (with the weirdest colour assignments, black and white are RX/TX, blue is ground, green is 5V, and there’s also a U_G and a DC pin, latter I think has the full 24/36V rail exposed from the motor controller, but I’ll have to take that apart to confirm it).
Check out the Desktronic thread - it’s the same controller, and you can get it to work “okay”, albeit in a proxy mode, which is a bit janky.
I’m still working on trying to get the secondary UART working, which is used by e.g. the official (but unavailable for purchase) BT dongle.
