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)

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