ESPHome: what it is, how it works and what it is used for

ESPHome: what it is, how it works and what it is used for

The creator of the project Home Assistant, Paulus Schoutsen, has always advanced the idea of ​​a smart home that must be open and interoperable. In other words, companies that bring smart products to market don’t have to create closed ecosystems but it is advisable that they provide end users with “the keys” to make the various devices communicate, and to manage them centrally (even without relying on a cloud platform). We saw it in the article on the offline smart home to free oneself from the platforms of individual manufacturers and have the possibility of interacting with devices for smart home even without an Internet connection.

ESPHome it is a system that takes the concept to the extreme and allows you to manage the operation of a large array of microcontrollers through simple but powerful configuration files. Devices managed with ESPHome can be managed remotely, via home automation systems such as Home Assistant (but also OpenHAB e ioBroker).

Among other things, Schoutsen strongly wanted the establishment of Open Home Foundation, an independent reality that removes Home Assistant and many other projects from any economic interest and from acquisition by third parties. Among the projects that the foundation has placed under its protection there is also ESPHome.

Logo ESPHome

The main features of ESPHome

ESPHome is an open source framework created to simplify the control of microcontroller come ESP32 e ESP8266, using YAML configuration files. These configuration file they allow users to define the behavior of the microcontroller and easily integrate it into home automation systems, such as Home Assistant.

The system supports a wide range of microcontrollers, including ESP32, ESP8266, RP2040, BK72xx and RTL87xx, which become easily manageable in remote mode.

Through the framework it is possible to use, for example, PSRAM and Deep Sleep which in turn allow you to interact directly with the processor or processors mounted on the microcontroller. PSRAM it is a “pseudo” static memory that retains data even when the power is interrupted; The Deep Sleep is a power saving mode available on ESP32 and ESP8266 microcontrollers. When the microcontroller enters Deep Sleep, most of the device’s components turn off to reduce power consumption to a minimum. However, it is possible to configure the microcontroller to wake up from this mode in response to certain events, such as a pulse on a pin GPIO or a timer expiring.

With ESPHome, you can initiate communications via Ethernet and WiFi, take advantage of protocols such as MQTT, HTTP and WireGuard, send and receive information via Bluetooth and Bluetooth Low Energy (BLE), manage interfaces such as I²C, SPI and UART for connectivity with external devices.

ESPHome support also spans a wide range of sensors to monitor environments such as temperature, humidity, and air quality. The design is also compatible with switches, relays and buttons, offers support for LED lights, RGB lights and single-color lights, as well as several other additional possibilities.

How to use ESPHome

As mentioned previously, ESPHome was already born with the possibility of easily activating thedevice integration in Home Assistant, for centralized control and monitoring.

There is also the possibility of using a command line interface for configuration and management; you can also initially make use of a wide range of pre-configured projectsmentioned in the ESPHome documentation, which help to appreciate its potential.

The main advantage of ESPHome is its flexibility: IoT devices can be programmed with a high level language, without having to write native code. It works in two main phases: compiling and uploading the firmware.

During the compilation, ESPHome converts the configuration into native code for ESP8266, ESP32 or other microcontrollers. This process involves optimizing the code, generating custom firmware, and creating configuration files for the specific device. Once the firmware is compiled, you can upload it to the microcontroller by connecting the device via USB cable or, if it is already connected to a WiFi network, distribute the firmware via OTA update (Over-the-Air).

Installing ESPHome

To start using ESPHome, you need to install the firmware compilation and upload software locally. The essential requirement is to install the Python language, on Windows, Linux or macOS. The procedure to follow is summarized in these pages (refer to the links in the left column, depending on the platform in use).

On all operating systems, as a last step, for install ESPHome simply type the following:

pip3 install esphome

ESPHome provides automatic updates: It means you don’t need to worry about manually updating the firmware. The process of maintenance and updating devices much simpler and more convenient, especially for those installed in difficult to access locations.

How to configure ESPHome

To configure ESPHome, you need to create a YAML configuration. This is an element that describes the device, sensors, actuators and automation rules.

Below we propose an example of a configuration for a temperature sensor e humidity:

name: my_sensor
platform: ESP8266
board: nodemcu

ssid: “MyNetwork”
password: “MyPassword”

# DHT22 temperature and humidity sensor
– platform: dht
pin: D4
name: “Temperatura”
name: “Humidity”

# Output for the integrated LED
– platform: led
pin: 5
name: “LED”

# Adjust to turn on the LED when the temperature exceeds 25°C
– id: “temperature_alert”
aka: “Temperature alarm”
platform: numeric_state
entity_id: sensor.temperature
above: 25
service: output.turn_on
entity_id: output.led

Some comments on the contents of the example YAML file

The example file that we published in the previous paragraph specifies the use of an ESP8266 microcontroller. The section esphome defines the global settings for the ESPHome project. The name of the device, the reference to the hardware platform (ESP8266) and the specific model of the board (nodemcu).

Inside wifi the settings for the device’s WiFi connection are indicated while sensor configure the device sensors:

  • - platform: dht: A DHT22 sensor is used to measure temperature and humidity.
  • pin: The microcontroller pin to which the sensor is connected.
  • temperature: Temperature sensor configuration.
  • name: The name assigned to the temperature sensor.
  • humidity: Humidity sensor configuration.
  • name: The name assigned to the humidity sensor.

The section output is used to define the output. In this case, as evident from the reference - platform: led, an LED light is used. Here too, you assign a name to the LED and specify the pin of the microcontroller to which it is connected.

Acting on automationthe so-called automations can be explained, i.e. the actions that the device must perform in response to certain events:

  • - id: "temperature_alert": Unique identifier for the automation.
  • alias A “humanly” readable name for the automation in question.
  • trigger: The trigger that activates the automation.
  • platform: numeric_state: Automation is triggered when the specified numeric state changes.
  • entity_id: sensor.temperature: The temperature sensor is the entity that is monitored for change of state.
  • above: 25: The automation is activated when the temperature exceeds, in this case, 25°C.
  • action: The actions to perform when automation is enabled.
  • service: output.turn_on: ESPHome has the service that activates the specific output.
  • entity_id: output.led: The specific output to activate is, in this case, the LED.

Some examples of using ESPHome

The possibles application fields of ESPHome are practically boundless. The classic applications they include lighting, security, air conditioning and irrigation systems but, obviously, the scenarios that can be explored are in fact infinite.

By adopting ESPHome and using special microcontrollers, you can manage lights based on presence, movement or brightness; monitor the opening and closing of doors and windows, receiving notifications in the event of an intrusion; control heating and cooling based on room temperature and humidity; intervene on irrigation based on weather conditions and soil humidity.

The simplicity but, at the same time, the power of ESPHome with the…

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