main.cpp

#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFi.h>
#include <HTTPClient.h>

#define ONE_WIRE_BUS 4 // GPIO pin

const char* ssid = "";
const char* password = "";

int wiFiConnectTimeout = 10; //seconds
int sensorReadDelay = 60*15; //seconds

OneWire oneWire(ONE_WIRE_BUS);

DallasTemperature sensors(&oneWire);

void setup(){
  Serial.begin(115200);
  
  sensors.begin();
  sensors.requestTemperatures();

  Serial.print("Connecting to WiFi");
    
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  
  int wiFiConnectAttempts = 0;
  while(WiFi.status() != WL_CONNECTED && wiFiConnectAttempts++ < wiFiConnectTimeout) {
    Serial.print(".");
    delay(1000);
  }

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println(" FAILED!");
  } else {
    Serial.println(" OK!");


    Serial.print("Sending API request...");
    
    const String metricsServerUrl = "http://metrics-server/";
    
    HTTPClient http;
    http.setTimeout(3000);
    http.setConnectTimeout(3000);
    http.begin(metricsServerUrl);
    http.addHeader("Content-Type", "application/x-www-form-urlencoded");
    String httpRequestData = "instance=a&sensor[0]=" + String(sensors.getTempCByIndex(0));
    int httpResponseCode = http.POST(httpRequestData);

    http.end();

    if (httpResponseCode >= 200) {
      Serial.println(" OK!");
    } else {
      Serial.println(" FAIL!");
    }

    WiFi.disconnect(true, true);
    
  }
  
  Serial.println("Zzzzz");
  esp_deep_sleep(sensorReadDelay * 1000000);
}
 
void loop(){
}