Attention: I only have one RJ12 model to test this but it's likely that other Jiecang controllers are supported as their serial protocol should be compatible.

Usage

What you need

ESPHome compatible microcontroller
depending on your model of desk controller
- cable with RJ12 connector (phone cable, RJ11 may also work)
- cable with RJ45 connector (network cable)

Wiring

RJ12

Please double check this for your specific model!

pin	function
1	NC (pulled up)
2	GND
3	TX
4	VCC
5	RX
6	NC (pulled up)

RJ45

Untested and only for reference!

pin	function
1	HS3 ¹
2	TX
3	GND
4	RX
5	VCC
6	HS2 ¹
7	HS1 ¹
8	HS0 ¹

microcontroller

ESP	desk
GND	GND
5V	VCC
RX	TX
TX	RX

Usage

esphome:
  ...
  on_boot:
    # This script is required to initialize the following sensors:
    #    height_pct, height_min, height_max, position1 - position4
    # You can skip this if you don't use those.
    priority: 0 # when mostly everything else is done
    then:
      - lambda: "id(my_desk).request_physical_limits();"
      - delay: 0.1s
      - lambda: "id(my_desk).request_limits();"
      - delay: 0.1s
      - lambda: "id(my_desk).request_settings();"

external_components:
  - source:
      type: git
      url: https://github.com/Rocka84/esphome_components/
    components: [ jiecang_desk_controller ]

uart:
  id: uart_bus
  tx_pin: TX
  rx_pin: RX
  baud_rate: 9600

logger:
  baud_rate: 0 # disable logging over uart, required when using the RX/TX pins for the controller

jiecang_desk_controller:
  id: my_desk
  sensors:
    height:
      name: "Height"
  numbers:
    height:
      name: "Height"
  buttons:
    move_up:
      name: "Move up"
    move_down:
      name: "Move down"
    stop:
      name: "Stop"
    position1:
      name: "Position 1"

button:
  - platform: template
    name: "Step down"
    on_press:
      lambda: "id(my_desk).goto_height(84.0);"

Examples

basic, sufficient for most people: example_basic.yaml
full with all features in use: example_full.yaml

Features

sensors

sensor	description
height	current height of the desk
height_pct	height in percent
height_min	minimal height
height_max	maximal height
position1	1st stored height
position2	2nd stored height
position3	3rd stored height
position4	4th stored height

number entities

Hold current values read from the desk and set values to desk when changed.

sensor	description
height	current height of the desk

buttons

button	description
step_up	move up desk by one step (~14mm)
step_down	move down desk by one step (~14mm)
move_up	move up until stopped
move_down	move down until stopped
stop	stop movement of desk
position1	move to 1st stored height
position2	move to 2nd stored height
position3	move to 3rd stored height
position4	move to 4th stored height
save_position	press position button afterwards to store current height to that position

lambda methods

lambda method	description
`id(my_desk).step_up()`	step_up desk by one step (~14mm)
`id(my_desk).step_down()`	step_down desk by one step (~14mm)
`id(my_desk).move_up()`	move up
`id(my_desk).move_down()`	move down
`id(my_desk).stop()`	stop movement of desk
`id(my_desk).goto_position(pos)`	move to stored height `pos`
`id(my_desk).save_position(pos)`	save current height to position `pos`
`id(my_desk).goto_height(height)`	move to specified height

Case

You can find a 3D-printable case in the stl folder or on onshape.

Sources

Thanks to phord/Jarvis for reverse engineering the UART interface and most control messages!
Thanks to OkhammahkO for collecting the scattered information at pimp-my-desk/desk-control and for his work in the home assistant community!

not used here ↩︎