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

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

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
    unknown_position:
      name: Chenyang Window Unknown Position

Dooya:

cover:
  - platform: dooya
    name: Dooya Shade
    address: 0xFEFE
    device_class: shade

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
    unknown_position:
      name: GM40 Curtain Unknown Position

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.