main.cpp

#include "esphomelib/application.h"

#ifdef ARDUINO_ARCH_ESP32
#include <WiFi.h>
#else
#include <ESP8266WiFi.h>
#endif

using namespace esphomelib;

// DEFINE CUSTOM SENSOR
class WiFiSignalSensor : public sensor::PollingSensorComponent {
 public:
  WiFiSignalSensor(const std::string &friendly_name, uint32_t update_interval)
      : sensor::PollingSensorComponent(friendly_name, update_interval) {}

  void update() override { push_new_value(WiFi.RSSI()); }
  std::string unit_of_measurement() override { return "dB"; }
  int8_t accuracy_decimals() override { return 2; }
};

void setup() {
  // ===== DO NOT EDIT ANYTHING BELOW THIS LINE =====
  // ========== AUTO GENERATED CODE BEGIN ===========
  App.set_name("test");
  App.init_log();

  App.init_wifi("YOUR_SSID", "YOUR_PASSWORD");
  App.init_ota()->start_safe_mode();
  App.init_mqtt("MQTT_HOST", "USERNAME", "PASSWORD");

  // =========== AUTO GENERATED CODE END ============
  // ========= YOU CAN EDIT AFTER THIS LINE =========
  auto *custom_sensor = App.register_component(new WiFiSignalSensor("Custom Sensor Example", 5000));
  App.register_sensor(custom_sensor);

  App.setup();
}

void loop() {
  App.loop();
}