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

// Replace with your network credentials
const char* ssid     = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";

// REPLACE with your Domain name and URL path or IP address with path
const char* serverName = "https://api.thingspeak.com/update?";

String apiKeyValue = "YOUR_THINGSPEAK_API_KEY";

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());
}

void loop() {
  //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");

    // Prepare your HTTP POST request data
    String httpRequestData = "api_key=" + apiKeyValue + "&field1=" + random(0,20);
    Serial.print("httpRequestData: ");
    Serial.println(httpRequestData);


    // Send HTTP POST request
    int httpResponseCode = http.POST(httpRequestData);

    if (httpResponseCode>0) {
      Serial.print("HTTP Response code: ");
      Serial.println(httpResponseCode);
    }
    else {
      Serial.print("Error code: ");
      Serial.println(httpResponseCode);
    }
    // Free resources
    http.end();
  }
  else {
    Serial.println("WiFi Disconnected");
  }
  //Send an HTTP POST request every 30 seconds
  delay(10000);
}