Configuration Types

ESPHome’s configuration files have several configuration types. This page describes them.

ID

Quite an important aspect of ESPHome are “ids”. They are used to connect components from different domains. For example, you define an output component together with an id and then later specify that same id in the light component. IDs should always be unique within a configuration and ESPHome will warn you if you try to use the same ID twice.

Because ESPHome converts your configuration into C++ code and the ids are in reality just C++ variable names, they must also adhere to C++’s naming conventions. C++ Variable names

  • … must start with a letter and can end with numbers.

  • … must not have a space in the name.

  • … can not have special characters except the underscore (“_“).

  • … must not be a keyword.

Pin

ESPHome always uses the chip-internal GPIO numbers. These internal numbers are always integers like 16 and can be prefixed by GPIO. For example to use the pin with the internal GPIO number 16, you could type GPIO16 or just 16.

Most boards however have aliases for certain pins. For example the NodeMCU ESP8266 uses pin names D0 through D8 as aliases for the internal GPIO pin numbers. Each board (defined in ESPHome section) has their own aliases and so not all of them are supported yet. For example, for the D0 (as printed on the PCB silkscreen) pin on the NodeMCU ESP8266 has the internal GPIO name GPIO16, but also has an alias D0. So using either one of these names in your configuration will lead to the same result.

some_config_option:
  pin: GPIO16

some_config_option:
  # alias on the NodeMCU ESP8266:
  pin: D0

Pin Schema

In some places, ESPHome also supports a more advanced “pin schema”.

some_config_option:
  # Basic:
  pin: D0

  # Advanced:
  pin:
    number: D0
    inverted: True
    mode: INPUT_PULLUP

Configuration variables:

  • number (Required, pin): The pin number.

  • inverted (Optional, boolean): If all read and written values should be treated as inverted. Defaults to False.

  • mode (Optional, string): A pin mode to set for the pin at startup, corresponds to Arduino’s pinMode call.

Available Pin Modes:

  • INPUT

  • OUTPUT

  • OUTPUT_OPEN_DRAIN

  • ANALOG (only on ESP32)

  • INPUT_PULLUP

  • INPUT_PULLDOWN (only on ESP32)

  • INPUT_PULLDOWN_16 (only on ESP8266 and only on GPIO16)

More exotic Pin Modes are also supported, but rarely used:

  • WAKEUP_PULLUP (only on ESP8266)

  • WAKEUP_PULLDOWN (only on ESP8266)

  • SPECIAL

  • FUNCTION_0 (only on ESP8266)

  • FUNCTION_1

  • FUNCTION_2

  • FUNCTION_3

  • FUNCTION_4

  • FUNCTION_5 (only on ESP32)

  • FUNCTION_6 (only on ESP32)

Color

When using RGB-capable displays or LEDs/lighting in ESPHome you may wish to use custom colors. A color component exists for just this purpose:

color:
  - id: my_light_red
    red: 100%
    green: 20%
    blue: 25%
    white: 0%

RGB displays use red, green, and blue, while grayscale displays may use white. LEDs or LED-based light bulbs may use all four color elements depending on their capabilities.

Time

In lots of places in ESPHome you need to define time periods. There are several ways of doing this. See below examples to see how you can specify time periods:

some_config_option:
  some_time_option: 1000us  # 1000 microseconds = 1ms
  some_time_option: 1000ms  # 1000 milliseconds
  some_time_option: 1.5s  # 1.5 seconds
  some_time_option: 0.5min  # half a minute
  some_time_option: 2h  # 2 hours

  # Make sure you wrap these in quotes
  some_time_option: '2:01'  # 2 hours 1 minute
  some_time_option: '2:01:30'  # 2 hours 1 minute 30 seconds

  # 10ms + 30s + 25min + 3h
  some_time_option:
    milliseconds: 10
    seconds: 30
    minutes: 25
    hours: 3
    days: 0

  # for all 'update_interval' options, also
  update_interval: never  # never update
  update_interval: 0ms  # update in every loop() iteration

Substitutions

Starting with version 1.10.0, ESPHome has a powerful new way to reduce repetition in configuration files: Substitutions. With substitutions, you can have a single generic source file for all nodes of one kind and substitute expressions in.

substitutions:
  devicename: livingroom
  upper_devicename: Livingroom

esphome:
  name: $devicename
  # ...

sensor:
- platform: dht
  # ...
  temperature:
    name: ${upper_devicename} Temperature
  humidity:
    name: ${upper_devicename} Humidity

In the top-level substitutions section, you can put as many key-value pairs as you want. Before validating your configuration, ESPHome will automatically replace all occurrences of substitutions by their value. The syntax for a substitution is based on bash and is case-sensitive: $substitution_key or ${substitution_key} (same).

Additionally, you can use the YAML << syntax to create a single YAML file from which a number of nodes inherit:

# In common.yaml
esphome:
  name: $devicename
  # ...

sensor:
- platform: dht
  # ...
  temperature:
    name: ${upper_devicename} Temperature
  humidity:
    name: ${upper_devicename} Humidity
# In nodemcu1.yaml
substitutions:
  devicename: nodemcu1
  upper_devicename: NodeMCU 1

<<: !include common.yaml

Tip

To hide these base files from the dashboard, you can

  • Place them in a subdirectory (dashboard only shows files in top-level dir)

  • Prepend a dot to the filename, like .base.yaml

Command line substitutions

You can define or override substitutions from the command line by adding e.g. -s KEY VALUE which overrides substitution KEY and gives it value VALUE. This can be issued multiple times, so e.g. with the following example.yaml file:

substitutions:
  name: default
  platform: ESP8266

esphome:
  name: $name
  platform: $platform
  board: $board

and the following command:

esphome -s name device01 -s board esp01_1m example.yaml config

You will get something like the following output (please note the unchanged platform, added board, and overridden name substitutions):

substitutions:
  name: device01
  platform: ESP8266
  board: esp01_1m
esphome:
  name: device01
  platform: ESP8266
  board: esp01_1m
  includes: []
  board_flash_mode: dout
  libraries: []
  esp8266_restore_from_flash: false
  build_path: device01
  platformio_options: {}
  arduino_version: espressif8266@2.2.3

We can observe here that command line substitutions take precedence over the ones in your configuration file. This can be used to create generic ‘template’ configuration files (like the example.yaml above) which can be used for multiple devices, using substitutions which are provided on the command line.

Packages

Another way to modularize and reuse your configuration is to use packages. This feature allows you to put common pieces of configuration in separate files and keep only unique pieces of your config in the main yaml file. All definitions from packages will be merged with your main config in non-destructive way so you could always override some bits and pieces of package configuration.

Consider the following example where author put common pieces of configuration like WiFi, I2C into base files and extends it with some devices specific configurations in the main config.

Note how the piece of configuration describing api component in device_base.yaml gets merged with the services definitions from main config file.

# In config.yaml
substitutions:
  node_name: mydevice
  device_verbose_name: "My Device"

packages:
  wifi: !include common/wifi.yaml
  device_base: !include common/device_base.yaml

api:
  services:
    - service: start_laundry
      then:
        - switch.turn_on: relay
        - delay: 3h
        - switch.turn_off: relay

sensor:
  - platform: mhz19
    co2:
      name: "CO2"
    temperature:
      name: "Temperature"
    update_interval: 60s
    automatic_baseline_calibration: false
# In wifi.yaml
wifi:
  ssid: "your_ssid"
  password: !secret wifi_password
  domain: .yourdomain.lan
  fast_connect: true
# In device_base.yaml
esphome:
  name: ${node_name}
  platform: ESP32
  board: wemos_d1_mini32
  build_path: ./build/${node_name}

# I2C Bus
i2c:
  sda: GPIO21
  scl: GPIO22
  scan: True
  frequency: 100kHz

# Enable logging
logger:
  level: ${log_level}

api:
  password: !secret hass_api_key
  reboot_timeout: 1h

sensor:
  - <<: !include common/sensor/uptime.config.yaml
  - <<: !include common/sensor/wifi_signal.config.yaml
binary_sensor:
  - <<: !include common/binary_sensor/connection_status.config.yaml

switch:
  - !include common/switch/restart_switch.config.yaml