esphome-docs/custom/custom_component.rst
2020-12-21 13:55:44 +13:00

174 lines
5.7 KiB
ReStructuredText

Generic Custom Component
========================
This integration can be used to create generic custom components in ESPHome
using the C++ (Arduino) API. This integration should be used in cases where
none of ESPHome's abstraction layers (for example the "sensor", "binary sensor",
"switch", etc concepts) work well for your integration.
Please first read :doc:`/components/sensor/custom` guide, the same principles apply here.
The example below is an example of a custom component that can do anything you want really.
.. code-block:: cpp
#include "esphome.h"
class MyCustomComponent : public Component {
public:
void setup() override {
// This will be called once to set up the component
// think of it as the setup() call in Arduino
pinMode(5, INPUT);
pinMode(6, OUTPUT);
}
void loop() override {
// This will be called very often after setup time.
// think of it as the loop() call in Arduino
if (digitalRead(5)) {
digitalWrite(6, HIGH);
// You can also log messages
ESP_LOGD("custom", "The GPIO pin 5 is HIGH!");
}
}
};
(Store this file in your configuration directory, for example ``my_custom_component.h``)
And in YAML:
.. code-block:: yaml
# Example configuration entry
esphome:
includes:
- my_custom_component.h
custom_component:
- lambda: |-
auto my_custom = new MyCustomComponent();
return {my_custom};
Configuration variables:
- **lambda** (**Required**, :ref:`lambda <config-lambda>`): The lambda to run for instantiating the
binary sensor(s).
See also :apiclass:`Component`.
Native API Custom Component
---------------------------
If you want to communicate directly with Home Assistant via the :doc:`native API </components/api>`
you can use the :apiclass:`CustomAPIDevice` class to declare services that can be executed from
Home Assistant, as well as starting services in Home Assistant.
.. code-block:: cpp
#include "esphome.h"
class MyCustomComponent : public Component, public CustomAPIDevice {
public:
void setup() override {
// This will be called once to set up the component
// think of it as the setup() call in Arduino
pinMode(6, OUTPUT);
// Declare a service "hello_world"
// - Service will be called "esphome.<NODE_NAME>_hello_world" in Home Assistant.
// - The service has no arguments
// - The function on_hello_world declared below will attached to the service.
register_service(&MyCustomComponent::on_hello_world, "hello_world");
// Declare a second service "start_washer_cycle"
// - Service will be called "esphome.<NODE_NAME>_start_washer_cycle" in Home Assistant.
// - The service has three arguments (type inferred from method definition):
// - cycle_duration: integer
// - silent: boolean
// - string_argument: string
// - The function start_washer_cycle declared below will attached to the service.
register_service(&MyCustomComponent::on_start_washer_cycle, "start_washer_cycle",
{"cycle_duration", "silent", "string_argument"});
// Subscribe to a Home Assistant state "sensor.temperature"
// - Each time the ESP connects or Home Assistant updates the state, the function
// on_state_changed will be called
// - The state is a string - if you want to use it as an int you must parse it manually
subscribe_homeassistant_state(&MyCustomComponent::on_state_changed, "sensor.temperature");
}
void on_hello_world() {
ESP_LOGD("custom", "Hello World!");
if (is_connected()) {
// Example check to see if a client is connected
}
}
void on_start_washer_cycle(int cycle_duration, bool silent, std::string string_argument) {
ESP_LOGD("custom", "Starting washer cycle!");
digitalWrite(8, HIGH);
// do something with arguments
// Call a homeassistant service
call_homeassistant_service("homeassistant.service");
}
void on_state_changed(std::string state) {
ESP_LOGD(TAG, "Temperature has changed to %s", state.c_str());
}
};
See also :apiclass:`CustomAPIDevice`.
MQTT Custom Component
---------------------
In many cases however components should communicate with other appliances using the network.
That's why there is :apiclass:`mqtt::CustomMQTTDevice`. It is a helper class to create
custom components that communicate using MQTT.
.. code-block:: cpp
#include "esphome.h"
class MyCustomComponent : public Component, public CustomMQTTDevice {
public:
void setup() override {
// This will be called once to set up the component
// think of it as the setup() call in Arduino
pinMode(6, OUTPUT);
subscribe("the/topic", &MyCustomComponent::on_message);
// also supports JSON messages
subscribe_json("the/json/topic", &MyCustomComponent::on_json_message);
}
void on_message(const std::string &payload) {
if (payload == "ON") {
digitalWrite(6, HIGH);
publish("the/other/topic", "Hello World!");
} else {
digitalWrite(6, LOW);
publish("the/other/topic", 42);
}
}
void on_json_message(JsonObject &root) {
if (!root.containsKey("key"))
return;
int value = root["key"];
// do something with Json Object
// publish JSON using lambda syntax
publish_json("the/other/json/topic", [=](JsonObject &root2) {
root2["key"] = "Hello World";
});
}
};
See also :apiclass:`mqtt::CustomMQTTDevice`.
See Also
--------
- :ghedit:`Edit`