Chain Encoder ESPHome Component

Chain Encoder is a rotary encoder input node in the M5Stack Chain series. It integrates an AB rotary encoder that detects the rotation direction and pulse count, and the center of the knob supports button input. It also integrates a programmable RGB LED for status indication and interactive display. The encoder cap features a LEGO-compatible hole structure for more creative structural connections, making it suitable for human-machine interaction, smart home control, and other applications.

Note

To use Chain series nodes, a compatible host is required for UART communication and control, such as the Chain DualKey host, or an Atom series device paired with the Atomic ToChain Base.

1. Component Overview

Item	Information
Expansion module	Chain Encoder (U207)
Main functions	Provides rotary encoder input and button detection
Communication interface	Chain Bus / UART
ESPHome components	`m5_chain_base`, `m5_chain_encoder` (external components)
ESPHome version requirement	2026.9.0 or later

2. Component Details

Include External Components

Configuration Example

Configure the host UART pins (using the Chain DualKey as an example)

uart:
  - id: chain_uart_right
    tx_pin: GPIO6
    rx_pin: GPIO5
    baud_rate: 115200

  - id: chain_uart_left
    tx_pin: GPIO47
    rx_pin: GPIO48
    baud_rate: 115200 

Include the external components

external_components:
  - source: github://m5stack/esphome@feat-m5-chain
    components: [m5_chain_base, m5_chain_encoder]
    refresh: 0s 

Add the Chain Encoder

m5_chain_encoder:
  id: chain_encoder
  uart_id: chain_uart_right
  chain_index: 1
  update_interval: 50ms 

Set the correct index according to the actual position of the Chain.

Add Chain Encoder value and increment sensors

sensor:
  - platform: m5_chain_encoder
    m5_chain_encoder_id: chain_encoder
    name: "Chain Encoder Value"
    type: value
  - platform: m5_chain_encoder
    m5_chain_encoder_id: chain_encoder
    name: "Chain Encoder Increment"
    type: increment 

Add the Chain Encoder binary sensor

binary_sensor:
  - platform: m5_chain_encoder
    m5_chain_encoder_id: chain_encoder
    name: "Chain Encoder Button" 

Add the Chain Encoder RGB LED

output:
  - platform: m5_chain_encoder
    id: chain_encoder_red
    m5_chain_encoder_id: chain_encoder
    channel: rgb_red
  - platform: m5_chain_encoder
    id: chain_encoder_green
    m5_chain_encoder_id: chain_encoder
    channel: rgb_green
  - platform: m5_chain_encoder
    id: chain_encoder_blue
    m5_chain_encoder_id: chain_encoder
    channel: rgb_blue

light:
  - platform: rgb
    name: Chain Encoder RGB
    red: chain_encoder_red
    green: chain_encoder_green
    blue: chain_encoder_blue 

3. Reference Example

After the Chain Encoder expansion module is connected, you can view the corresponding Sensor and Light entities on the device page:

Dashboard card example

Next Overview

Page Tools

PDF

Home Assistant

HAOS

ESPHome

Controller & Devices

Cameras

Components

Sensors

Lighting

Input Devices

Chain Series

Switches and Relays

Audio Devices

Interfaces and Expansion

Applications

Voice Assistant

Media Playback

Dashboard