Chain Series ESPHome Component

The Chain Series provides input functions such as buttons, rotary controls, joysticks, angle measurement, and distance measurement through the Chain Bus.

1. Component Overview

Item	Information
Series	Chain Series
Expansion modules	Chain Key (U206), Chain Angle (U208), Chain Encoder (U207), Chain Joystick (U205), Chain ToF (U209)
Main functions	Button, rotary control, joystick, angle, and distance inputs
Communication interface	Chain Bus / UART
ESPHome component	m5stack_chain_* (external component)
ESPHome version requirement	/

2. Component Details

Include External Components

Master is the system's main controller. When connecting expansion sensors, set the connection direction and ID sequence correctly.

Select the Direction

Select the uart_id according to the side of the Master to which the expansion sensor is connected:

Left side of the Master: use chain_uart_left.
Right side of the Master: use chain_uart_right.

ID Assignment Rules

chain_id indicates the expansion sensor's position relative to the Master:

Start numbering with the module closest to the Master.
Increment IDs by distance (ID:1 鈫?ID:2 鈫?ID:3 鈥?.
Number the left and right sides independently.
Use the diagram above to verify the order.

Configuration Example

uart_id: chain_uart_left
chain_id: 1

Chain DualKey

For the Chain DualKey controller's UART, buttons, power, and lighting configuration, see Chain DualKey ESPHome integration. This page covers only expansion modules connected to the Chain Bus.

Chain Key

external_components:
  - source: github://m5stack/esphome-yaml/components
    components: [m5stack_chain_key]
    refresh: 0s

binary_sensor:
  - platform: m5stack_chain_key
    id: chain_key_1
    name: "Chain Key Button"
    uart_id: chain_uart_left
    chain_id: 1
    update_interval: 50ms

output:
  - platform: m5stack_chain_key
    id: chain_key_rgb_r
    chain_key_id: chain_key_1
    channel: rgb_red

  - platform: m5stack_chain_key
    id: chain_key_rgb_g
    chain_key_id: chain_key_1
    channel: rgb_green

  - platform: m5stack_chain_key
    id: chain_key_rgb_b
    chain_key_id: chain_key_1
    channel: rgb_blue

light:
  - platform: rgb
    name: "Key RGB"
    red: chain_key_rgb_r
    green: chain_key_rgb_g
    blue: chain_key_rgb_b 

Chain Angle

external_components:
  - source: github://m5stack/esphome-yaml/components
    components: [m5stack_chain_angle]
    refresh: 0s

sensor:
  - platform: m5stack_chain_angle
    id: chain_angle_1
    name: "Chain Angle"
    uart_id: chain_uart_left
    chain_id: 1
    update_interval: 200ms

output:
  - platform: m5stack_chain_angle
    id: chain_angle_rgb_r
    chain_angle_id: chain_angle_1
    channel: rgb_red

  - platform: m5stack_chain_angle
    id: chain_angle_rgb_g
    chain_angle_id: chain_angle_1
    channel: rgb_green

  - platform: m5stack_chain_angle
    id: chain_angle_rgb_b
    chain_angle_id: chain_angle_1
    channel: rgb_blue

light:
  - platform: rgb
    name: "Angle RGB"
    red: chain_angle_rgb_r
    green: chain_angle_rgb_g
    blue: chain_angle_rgb_b 

Chain Encoder

external_components:
  - source: github://m5stack/esphome-yaml/components
    components: [m5stack_chain_encoder]
    refresh: 0s

sensor:
  - platform: m5stack_chain_encoder
    id: chain_encoder_1
    name: "Chain Encoder"
    uart_id: chain_uart_left
    chain_id: 1
    update_interval: 100ms

output:
  - platform: m5stack_chain_encoder
    id: chain_encoder_rgb_r
    chain_encoder_id: chain_encoder_1
    channel: rgb_red

  - platform: m5stack_chain_encoder
    id: chain_encoder_rgb_g
    chain_encoder_id: chain_encoder_1
    channel: rgb_green

  - platform: m5stack_chain_encoder
    id: chain_encoder_rgb_b
    chain_encoder_id: chain_encoder_1
    channel: rgb_blue

light:
  - platform: rgb
    name: "Encoder RGB"
    red: chain_encoder_rgb_r
    green: chain_encoder_rgb_g
    blue: chain_encoder_rgb_b

binary_sensor:
  - platform: m5stack_chain_encoder
    name: "Encoder Button"
    chain_encoder_id: chain_encoder_1 

Chain Joystick

external_components:
  - source: github://m5stack/esphome-yaml/components
    components: [m5stack_chain_joystick]
    refresh: 0s

sensor:
  - platform: m5stack_chain_joystick
    id: chain_joystick_x
    name: "Chain Joystick X"
    uart_id: chain_uart_left
    chain_id: 1
    axis: x
    update_interval: 50ms

  - platform: m5stack_chain_joystick
    name: "Chain Joystick Y"
    uart_id: chain_uart_left
    chain_id: 1
    axis: y
    update_interval: 50ms

output:
  - platform: m5stack_chain_joystick
    id: chain_joystick_rgb_r
    chain_joystick_id: chain_joystick_x
    channel: rgb_red

  - platform: m5stack_chain_joystick
    id: chain_joystick_rgb_g
    chain_joystick_id: chain_joystick_x
    channel: rgb_green

  - platform: m5stack_chain_joystick
    id: chain_joystick_rgb_b
    chain_joystick_id: chain_joystick_x
    channel: rgb_blue

light:
  - platform: rgb
    name: "Joystick RGB"
    red: chain_joystick_rgb_r
    green: chain_joystick_rgb_g
    blue: chain_joystick_rgb_b

binary_sensor:
  - platform: m5stack_chain_joystick
    name: "Joystick Button"
    chain_joystick_id: chain_joystick_x 

Chain ToF

external_components:
  - source: github://m5stack/esphome-yaml/components
    components: [m5stack_chain_tof]
    refresh: 0s

sensor:
  - platform: m5stack_chain_tof
    id: chain_tof_1
    name: "Chain ToF"
    uart_id: chain_uart_left
    chain_id: 1
    update_interval: 200ms

output:
  - platform: m5stack_chain_tof
    id: chain_tof_rgb_r
    m5stack_chain_tof_id: chain_tof_1
    channel: rgb_red

  - platform: m5stack_chain_tof
    id: chain_tof_rgb_g
    m5stack_chain_tof_id: chain_tof_1
    channel: rgb_green

  - platform: m5stack_chain_tof
    id: chain_tof_rgb_b
    m5stack_chain_tof_id: chain_tof_1
    channel: rgb_blue

light:
  - platform: rgb
    name: "ToF RGB"
    red: chain_tof_rgb_r
    green: chain_tof_rgb_g
    blue: chain_tof_rgb_b 

Combined Example

Multiple Chain expansion modules can share one UART bus. Assign each module's chain_id from the Master outward; number the buses on the left and right sides independently. Configure the Master UART pins, Chain Bus power, and onboard functions on the device page for the selected controller.

The complete configuration uses Chain DualKey as the Master and includes all five Chain expansion module types:

3. Reference Example

After the Chain expansion modules are connected, the device page displays the corresponding Sensor, Binary Sensor, and Light entities:

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