heltec_variable_json_post.ino

#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>


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

//Your Domain name with URL path or IP address with path
//const char* serverName = "http://192.168.1.106:1880/update-sensor";

const char* serverName = "https://edgecollective.farmos.net/farm/sensor/listener/47803f44fef9cf01489d033d2eef4424?private_key=9f6a52fb667566b828069794274fad22";
// the following variables are unsigned longs because the time, measured in
// milliseconds, will quickly become a bigger number than can be stored in an int.

unsigned long lastTime = 0;
// Timer set to 10 minutes (600000)
//unsigned long timerDelay = 600000;
// Set timer to 90 seconds (5000)
unsigned long timerDelay = 90000;

    StaticJsonDocument<200> doc;


void setup() {

    
  Serial.begin(115200);

  WiFi.begin(ssid, password);
  Serial.println("Connecting");
  while(WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to WiFi network with IP Address: ");
  Serial.println(WiFi.localIP());
 
  Serial.println("Timer set to 5 seconds (timerDelay variable), it will take 5 seconds before publishing the first reading.");
}

void loop() {

  doc["temp"] = 23.5;
  doc["humidity"] = 50.2;

  //serializeJson(doc, Serial);

  //Send an HTTP POST request every 10 minutes
  if ((millis() - lastTime) > timerDelay) {
    //Check WiFi connection status
    if(WiFi.status()== WL_CONNECTED){
      HTTPClient http;
      
      // Your Domain name with URL path or IP address with path
      http.begin(serverName);

      // Specify content-type header
      //http.addHeader("Content-Type", "application/x-www-form-urlencoded");
      // Data to send with HTTP POST
      //String httpRequestData = "api_key=tPmAT5Ab3j7F9&sensor=BME280&value1=24.25&value2=49.54&value3=1005.14";           
      // Send HTTP POST request
      //int httpResponseCode = http.POST(httpRequestData);
      
      // If you need an HTTP request with a content type: application/json, use the following:
      http.addHeader("Content-Type", "application/json");
      
      //int httpResponseCode = http.POST("{\"api_key\":\"tPmAT5Ab3j7F9\",\"sensor\":\"BME280\",\"value1\":\"24.25\",\"value2\":\"49.54\",\"value3\":\"1005.14\"}");

String output;
  serializeJson(doc, output);

int httpResponseCode = http.POST(output);

     
      Serial.print("HTTP Response code: ");
      Serial.println(httpResponseCode);
        
      // Free resources
      http.end();
    }
    else {
      Serial.println("WiFi Disconnected");
    }
    lastTime = millis();
  }
}

why httpResponseCode results -1?