esphome-rs485

Connect various UART devices over a multipoint/multidrop interface such as RS485 to an ESP8266 or ESP32 using the ESPHome framework.

Features

• Control devices from and poll state updates to Home Assistant.
• State updates of default 500ms interval between devices.

Requirements

• ESPHome 1.18.0 or greater
• All RS485 devices connected on the same bus must be using the same baud rate

Supported Microcontrollers

This library should work on most ESP8266 or ESP32 platforms. It has been tested with the following MCUs:

• Generic ESP-01S board (ESP8266)
• WeMos D1 Mini (ESP8266)
• Generic ESP32 Dev Kit (ESP32)

Supported Devices

• Chenyang RS485 Window Opener CP12, CP14, CP16, CP31, CP95
• Dooya Curtain RS485 Motor DT82TV
• Dooya Shade RS485 Motor DM35EQL/J & DM45EQL/J
• GM40 RS485 Curtain Motor

Usage

Step 1: Link up the devices and microcontroller to a multipoint bus.

Connect the RS485 devices and microcontroller together. You can use a UART-RS485 board such as the SP3485 to interface the microcontroller to the RS485 devices.

Step 2: Use ESPHome 1.18.0 or higher

The code in this repository makes use of the external components feature in the 1.18.0 version of ESPHome.

v1.1.0 and above requires ESPHome 2025.5.0 or higher.

Step 3: Add this repository as an external component

Add the uart_multi component along with the devices you need to your ESPHome config:

external_components:
  - source: github://loongyh/esphome-rs485
    components: [ uart_multi, chenyang, dooya, ... ]

Define the UART pins your UART-RS485 board is connected to, as well as the baud rate of the RS485 devices:

uart:
  tx_pin: 17
  rx_pin: 16
  baud_rate: 9600

Step 4: Configure the devices

Chenyang:

cover:
  - platform: chenyang
    name: Chenyang Window
    address: 0xFF
    device_class: window

# Optional binary sensor for when window position is unknown on startup.
# An automation can be triggered to open and close the window to initialize the positioning.
binary_sensor:
  - platform: chenyang
    name: Chenyang Window Unknown Position

# Optional setting entities to configure the window opener on the frontend.
button:
  - platform: chenyang
    type: get_status
    name: Chenyang Window Get Status
  - platform: chenyang
    type: factory_reset
    name: Chenyang Window Factory Reset
  - platform: chenyang
    type: restart
    name: Chenyang Window Restart

number:
  - platform: chenyang
    type: speed
    name: Chenyang Window Speed
  - platform: chenyang
    type: torque
    name: Chenyang Window Torque

switch:
  - platform: chenyang
    type: led_indicator
    name: Chenyang Window LED Indicator
  - platform: chenyang
    type: invert_direction
    name: Chenyang Window Invert Direction
  - platform: chenyang
    type: pull_to_start
    name: Chenyang Window Pull to Start
  - platform: chenyang
    type: close_on_power_on
    name: Chenyang Window Close on Power On
  - platform: chenyang
    type: open_on_power_on
    name: Chenyang Window Open on Power On
  - platform: chenyang
    type: rain_sensor
    name: Chenyang Window Rain Sensor
  - platform: chenyang
    type: rain_invert_direction
    name: Chenyang Window Rain Invert Direction
  - platform: chenyang
    type: lock
    name: Chenyang Window Lock
  - platform: chenyang
    type: power_off_unlock
    name: Chenyang Window Power Off Unlock

Dooya:

cover:
  - platform: dooya
    name: Dooya Curtain
    address: 0xFEFE
    device_class: curtain

# Optional binary sensor for when curtain position is unknown on startup.
# An automation can be triggered to open and close the curtain to initialize the positioning.
binary_sensor:
  - platform: dooya
    name: Dooya Curtain Unknown Position

# Optional setting entities to configure the curtain on the frontend.
button:
  - platform: dooya
    type: get_status
    name: Dooya Curtain Get Status
  - platform: dooya
    type: clear_positioning
    name: Dooya Curtain Clear Positioning
  - platform: dooya
    type: factory_reset
    name: Dooya Curtain Factory Reset

switch:
  - platform: dooya
    type: invert_direction
    name: Dooya Curtain Invert Direction
  - platform: dooya
    type: pull_to_start
    name: Dooya Curtain Pull to Start

GM40:

cover:
  - platform: gm40
    name: GM40 Curtain
    address: 0x00
    device_class: curtain

# Optional binary sensor for when curtain position is unknown on startup.
# An automation can be triggered to open and close the curtain to initialize the positioning.
binary_sensor:
  - platform: gm40
    name: GM40 Curtain Unknown Position

# Optional setting entities to configure the curtain on the frontend.
button:
  - platform: gm40
    type: get_status
    name: GM40 Curtain Get Status
  - platform: gm40
    type: factory_reset
    name: GM40 Curtain Factory Reset
  - platform: gm40
    type: restart
    name: GM40 Curtain Restart

number:
  - platform: gm40
    name: GM40 Curtain Speed

switch:
  - platform: gm40
    type: invert_direction
    name: GM40 Curtain Invert Direction
  - platform: gm40
    type: led_indicator
    name: GM40 Curtain LED Indicator

On ESP8266 you'll need to disable logging to serial because it conflicts with the UART:

logger:
  baud_rate: 0

On ESP32 you can change hardware_uart to UART1 or UART2 and keep logging enabled on the main serial port.

Example configuration

Below is an example configuration which will include wireless strength indicators and permit over the air updates. You'll need to create a secrets.yaml file inside of your esphome directory with entries for the various items prefixed with !secret.

substitutions:
  name: rs485test
  friendly_name: Test RS485


esphome:
  name: ${name}
  platform: ESP8266
  board: esp01_1m
  # Boards tested: ESP-01S (ESP8266), Wemos D1 Mini (ESP8266); ESP32 Wifi-DevKit2

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "${friendly_name} Fallback Hotspot"
    password: !secret fallback_password

captive_portal:

# Enable logging
logger:
  # ESP8266 only - disable serial port logging, as the HeatPump component
  # needs the sole hardware UART on the ESP8266
  baud_rate: 0

# Enable Home Assistant API
api:

ota:

# Sync time with Home Assistant.
time:
  - platform: homeassistant
    id: homeassistant_time

external_components:
  - source: github://loongyh/esphome-rs485

uart:
  tx_pin: 17
  rx_pin: 16
  baud_rate: 9600

uart_multi:
  update_interval: 500ms

cover:
  - platform: dooya
    name: Dooya Shade
    address: 0xFEFE
    device_class: shade
  - platform: chenyang
    name: Chenyang Window
    address: 0xFF
    device_class: window
  - platform: gm40
    name: GM40 Curtain
    address: 0x00
    device_class: curtain

Configuration variables that affect this library directly

• hardware_uart (Optional): the hardware UART instance to use for communcation with the multipoint bus. On ESP8266, only UART0 is usable. On ESP32, UART0, UART1, and UART2 are all valid choices. Default: UART0
• baud_rate (Required): Serial BAUD rate used to communicate with the multipoint bus.
• update_interval (Optional, time): The delay polling for state updates between each device, in milliseconds. Smaller values at the expense of a busier bus and more collisions. Larger values at the expense of slower state updates. Default: 500ms

Contributing devices

Happy to accept contributions of new multipoint devices.