ESPHome Core Configuration

Here you specify some core information that ESPHome needs to create firmwares. Most importantly, this is the section of the configuration where you specify the name of the node.

# Example configuration entry
esphome:
    name: livingroom
    comment: Living room ESP32 controller

esp32:
    board: nodemcu-32s

Configuration variables:

  • name (Required, string): This is the name of the node. It should always be unique in your ESPHome network. May only contain lowercase characters, digits and hyphens, and can be at most 24 characters long by default, or 31 characters long if name_add_mac_suffix is false. See Changing ESPHome Node Name.

Advanced options:

  • build_path (Optional, string): Customize where ESPHome will store the build files for your node. By default, ESPHome puts the PlatformIO project it uses to build the firmware in the .esphome/build/<NODE> directory, but you can customize this behavior using this option.

  • platformio_options (Optional, mapping): Additional options to pass over to PlatformIO in the platformio.ini file. See platformio_options.

  • includes (Optional, list of files): A list of C/C++ files to include in the main (auto-generated) sketch file for custom components. The paths in this list are relative to the directory where the YAML configuration file is in. See includes.

  • libraries (Optional, list of libraries): A list of libraries to include in the project. See libraries.

  • comment (Optional, string): Additional text information about this node. Only for display in UI.

  • name_add_mac_suffix (Optional, boolean): Appends the last 3 bytes of the mac address of the device to the name in the form <name>-aabbcc. Defaults to false. See Adding the MAC address as a suffix to the device name.

  • project (Optional): ESPHome Creator’s Project information. See Project information.

    • name (Required, string): Name of the project

    • version (Required, string): Version of the project

  • min_version (Optional, string): The minimum ESPHome version required to compile this configuration. See Minimum ESPHome version.

  • compile_process_limit (Optional, int): The maximum number of simultaneous compile processes to run. Defaults to the number of cores of the CPU which is also the maximum you can set.

Old-style platform options, which have been moved to the platform-specific esp32 and esp8266 sections but are still accepted here for compatibility reasons (usage not recommended for new projects):

  • platform (Required, string): The platform used, either esp8266 or esp32.

  • board (Required, string): The board used, see esp32 and esp8266 for more information.

  • arduino_version (Optional, string): The version of the Arduino framework to compile the project against.

  • esp8266_restore_from_flash (Optional, boolean): For ESP8266s, whether to store some persistent preferences in flash memory.

Automations:

  • on_boot (Optional, Automation): An automation to perform when the node starts. See on_boot.

  • on_shutdown (Optional, Automation): An automation to perform right before the node shuts down. See on_shutdown.

  • on_loop (Optional, Automation): An automation to perform on each loop() iteration. See on_loop.

on_boot

This automation will be triggered when the ESP boots up. By default, it is executed after everything else is already set up. You can however change this using the priority parameter.

esphome:
  # ...
  on_boot:
    priority: 600
    # ...
    then:
      - switch.turn_off: switch_1

Configuration variables:

  • priority (Optional, float): The priority to execute your custom initialization code. A higher value means a high priority and thus also your code being executed earlier. Please note this is an ESPHome-internal value and any change will not be marked as a breaking change. Defaults to 600. Priorities (you can use any value between them too):

    • 800.0: This is where all hardware initialization of vital components is executed. For example setting switches to their initial state.

    • 600.0: This is where most sensors are set up.

    • 250.0: At this priority, WiFi is initialized.

    • 200.0: Network connections like MQTT/native API are set up at this priority.

    • -100.0: At this priority, pretty much everything should already be initialized.

  • See Automation.

on_shutdown

This automation will be triggered when the ESP is about to shut down. Shutting down is usually caused by too many WiFi/MQTT connection attempts, Over-The-Air updates being applied or through the Deep Sleep Component.

Note

It’s not guaranteed that all components are in a connected state when this automation is triggered. For example, the MQTT client may have already disconnected. For use-cases that require specific shutdown ordering, look at the priority parameter.

esphome:
  # ...
  on_shutdown:
    priority: 700
    then:
      - switch.turn_off: switch_1

Configuration variables:

  • priority (Optional, float): The priority to execute your custom shutdown code. A higher value means a high priority and in case of shutdown triggers that the code is executed later. Priority is used primarily for the initialization order of components. Shutdowns for these components are handled in reverse order, such that e.g. sensors (600) are shutdown before the hardware components (800) they depend on. Please note this is an ESPHome-internal value and any change will not be marked as a breaking change. Defaults to 600. For priority values refer to the list in the on_boot section.

  • See Automation.

on_loop

This automation will be triggered on every loop() iteration (usually around every 16 milliseconds).

esphome:
  # ...
  on_loop:
    then:
      # do something

platformio_options

PlatformIO supports a number of options in its platformio.ini file. With the platformio_options parameter you can tell ESPHome what options to pass into the env section of the PlatformIO file (note you can also do this by editing the platformio.ini file manually).

You can view a full list of PlatformIO options here: https://docs.platformio.org/en/latest/projectconf/section_env.html

# Example configuration entry
esphome:
  # ...
  platformio_options:
    upload_speed: 115200
    board_build.f_flash: 80000000L

includes

With includes you can include source files in the generated PlatformIO project. All files declared with this option are copied to the project each time it is compiled.

You can always look at the generated PlatformIO project (.esphome/build/<NODE>) to see what is happening - and if you want you can even copy the include files directly into the src/ folder. The includes option is only a helper option that does that for you.

# Example configuration entry
esphome:
  # ...
  includes:
    - my_switch.h

This option behaves differently depending on what the included file is pointing at:

  • If the include string is pointing at a directory, the entire directory tree is copied into the src/ folder.

  • If the include string points to a header file (.h, .hpp, .tcc), it is copied in the src/ folder AND included in the main.cpp file. This way the lambda code can access it.

  • If the include string points to a regular source file (.c, .cpp), it is copied in the src/ folder AND compiled into the binary. This way implementation of classes and functions in header files can be provided.

libraries

With the libraries option it is possible to include libraries in the PlatformIO project. These libraries will then be compiled into the resulting firmware, and can be used in code from lambdas and from custom components.

# Example configuration entry
esphome:
  # ...
  libraries:
    # a library from PlatformIO
    - espressif/esp32-camera

    # a library bundled with Arduino
    - Wire

    # use the git version of a library used by a component
    - esphome/Improv=https://github.com/improv-wifi/sdk-cpp.git#v1.0.0

The most common usage of this option is to include third-party libraries that are available in the PlatformIO registry. They can be added by listing their name under this option. It is also possible to use specific versions, or to fetch libraries from a file or git repository. ESPHome accepts the same syntax as the pio lib install command.

Using <name>=<source> syntax, it is possible to override the version used for libraries that are automatically added by one of ESPHome’s components. This can be useful during development to make ESPHome use a custom fork of a library.

By default, ESPHome does not include any libraries into the project. This means that libraries that are bundled with Arduino, such as Wire or EEPROM, aren’t available. If you need to use them, you should list them manually under this option. If they are used by another library, they should be listed before the library that uses them.

Adjusting flash writes

# Example configuration entry
preferences:
  flash_write_interval: 1min
  • flash_write_interval (Optional, Time): Customize the frequency in which data is flushed to the flash. This setting helps to prevent rapid changes to a component from being quickly written to the flash and wearing it out. Defaults to 1min.

As all devices have a limited number of flash write cycles, this setting helps to reduce the number of flash writes due to quickly changing components. In the past, when components such as light, switch, fan and globals were changed, the state was immediately committed to flash. The result of this was that the last state of these components would always restore to its last state on power loss, however, this has the cost of potentially quickly damaging the flash if these components are quickly changed.

A safety feature has thus been implemented to mitigate issues resulting from the limited number of flash write cycles, the state is first stored in memory before being flushed to flash after the flash_write_interval has passed. This results in fewer flash writes, preserving the flash health.

This behavior can be disabled by setting flash_write_interval to 0s to immediately commit the state to flash, however, be aware that this may lead to increased flash wearing and a shortened device lifespan!

For ESP8266, restore_from_flash must also be set to true for states to be written to flash.

Changing ESPHome Node Name

Trying to change the name of a node or its address in the network? You can do so with the use_address option of the WiFi configuration.

Change the device name or address in your YAML to the new value and additionally set use_address to point to the old address like so:

# Step 1. Changing name from test8266 to kitchen
esphome:
  name: kitchen
  # ...

wifi:
  # ...
  use_address: test8266.local

Now upload the updated config to the device. As a second step, you now need to remove the use_address option from your configuration again so that subsequent uploads will work again (otherwise it will try to upload to the old address).

# Step 2
esphome:
  name: kitchen
  # ...

wifi:
  # ...
  # Remove or comment out use_address
  # use_address: test8266.local

The same procedure can be done for changing the static IP of a device.

Adding the MAC address as a suffix to the device name

Using name_add_mac_suffix allows the user to compile a single binary file to flash many of the same device and they will all have unique names/hostnames. Note that you will still need to create an individual YAML config file if you want to OTA update the devices in the future.

Project information

This allows creators to add the project name and version to the compiled code. It is currently only exposed via the logger, mDNS and the device_info response via the native API. The format of the name should be author_name.project_name.

# Example configuration
esphome:
  ...
  project:
    name: "jesse.leds_party"
    version: "1.0.0"

Minimum ESPHome version

This allows YAML files to specify the minimum version of ESPHome required to compile. This is useful in the case of packages where a published package might use features only available in a newer version of ESPHome. This allows for a more friendly error message.

See Also