Intercept RJ45 connector to emulate key events on Standing desk controller (TiMotion TC16)

[distante]

I have an Standing Desk (height adjustable desk) that is controlled by this:

It has an RJ45 cable at the end that goes into the the desk control box

For what I have found, this is the official page of that controller https://www.timotion.com/en/products/control-boxes/tc16-series

I am searching for a way to integrate it into home assistant while keeping the “offline” functionality as it is.

My first idea was to buy something like this and connect it to an ESP32 board with ESPhome from where I can emulate the same button press that are done in the keypad.

That said, maybe I am being naive about how that thing works. Did anyone have done something similar?

Cheers!

[WallyR (Wally)]

You misunderstand the merger/splitter plug you have found.
Normally an ethernet cable only use wire 1+2 and 4+5 of the 8 wires available.
The merger/splitter plug will move wire 1+2 to 7+8 and 4+5 to 3+6 for one of the two connectors, thereby utilizing all 8 wires on the cable connected to the side with only 1 connector and later using the same plug to again split them out into two normal ethernet connectors.

In other words, for both connectors on the side with 2 connectors there will be no connection on wire 3,6,7 and 8.

[aceindy]

That said, the RJ45 connector most likely doesn’t even use a LAN signal, but just uses the 8 wires (or some of them) to control/feedback the actuator…

Did some searching…is this interesting?

Desky Standing Desk (ESPHome) [Works with Desky, Uplift, Jiecang, Assmann & others]

To get started: Take a look at the Option #1: ESPHome pass-through dongle solution Then check out the Option #2 Custom control panel (for more advanced set-up and features). This project could void your warranty or cause safety risks. Proceed at your own risk (I did;). Possible compatibility with other desks: Lots of desks use the same controllers. There’s a decent chance that if your desk uses a ‘Jiecang controller’ then this solution may work with no/minimal further changes. It likely w…

[WallyR (Wally)]

If the RJ45 connector is the only one connected to the button panel, then it is not that simply anymore.
You have 7 buttons and numbers and maybe even lights too.
With only 8 wires available it requires more than just a shorted wire here and there to make it work.

[distante]

ahh!! I knew it could not be that easy thanks for the explanation

[distante]

This looks interesting. Thank you for it. I did not used the correct search terms.

[Mahko_Mahko]

In the case of the Desky project, it uses both uart on one wire (for one way comms from controller to control panel) and shorts other wires (for control from panel to controller)!

This project might give you some structure for how to get started.

Turn your Desktronic standing desk into a smart desk!

This project could void your warranty or cause safety risks. Proceed at your own risk! I have already gathered some advice and tips from this thread and will share my approach with you. The desks in the thread unfortunately use a different controller and unfortunately I have not found a source on the internet that does this with a Desktronic desk. Table of Contents General Information Physical Structure Reading UART-Messages Thoughts and problems General Information Chip I use a d1mini chip.…

Doing a teardown of both controller and handset and posting photos, measuring voltages on wires on the handset side (probably accessible), pulling out the logic analyser, and setting up a ESPHome uart debug to try to read uart messages on wires are all good places to start.

This post shows how you can physically build a “pass through” type set-up (similar to your idea about the splitter) using an rj45 breakout.

Desky Standing Desk (ESPHome) [Works with Desky, Uplift, Jiecang, Assmann & others]

Option #1: Pass-Through Dongle (Simpler) Update note 2022-07-03: Might be worth looking over Option #2 config as I’ve made some enhancments/refinements there. I’m going to keep refining/editing this post as the main ‘how to’. The majority of credit for the solution so far goes to @ssieb . He generously donated his time and knowledge to decode the UART protocol and write the ESPHome custom component (I don’t know any C++, or much about UART either). He doesn’t have one of these desks. He may…

[movermeyer (Michael Overmeyer)]

I don’t have anything helpful to contribute yet, but that’s actually a TC15S series control box (not TC16, which doesn’t have the RJ45 connection), and the TDH6PR series controls.

Potentially helpful: they sell a Bluetooth dongle that connects to the RJ45 port instead, which might help with the debugging (perhaps the codes can be reverse engineered from their “Stand Up Pls” app?)

[movermeyer (Michael Overmeyer)]

Someone’s reverse-engineered the app’s communication to the dongle, for use in ESPHome: GitHub - duchu-net/esphome-timotion-desk-controller: ESPHome component for TiMOTION TWD1 Series desk control

So at least you wouldn’t have to use their app.
Still not as ideal as a pass-through.

[distante]

Thanks for the info! That looks really promising.

The only thing missing for me is to keep the control with the regular panel.