esp32tempsensor.ino

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

#define DHTPIN 4     // Digital pin connected to the DHT sensor
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

//-------- User Settings -----------
const char* ssid = "SSID";
const char* password = "PASSWORD";
const char* accesskey = "INITIAL STATE ACCESS KEY";
const char* bucketkey = "INITIAL STATE BUCKET KEY";
const char* signalname = "temperature";
//----------------------------------

HTTPClient ask;
int counter = 0;  
static bool hasWifi = false;

//////////////
// Network //
////////////

static void InitWifi()
{
  Serial.println("Connecting...");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  hasWifi = true;
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void setup()
{
  Serial.begin(115200);
  Serial.println("ESP32 Device");
  Serial.println("Initializing...");
  
  dht.begin();

  // Initialize the WiFi module
  Serial.println(" > WiFi");
  hasWifi = false;
  InitWifi();
  if (!hasWifi)
  {
    return;
  }
}

//////////////
//Send Data//
////////////

void loop(){
  if (WiFi.status() == WL_CONNECTED) { //if we are connected
    counter = 0; //reset counter
    Serial.println("Wifi is still connected with IP: "); 
    Serial.println(WiFi.localIP());   //inform user about his IP address
  }else if (WiFi.status() != WL_CONNECTED) { //if we lost connection, retry
    WiFi.begin(ssid);      
  }
  while (WiFi.status() != WL_CONNECTED) { //during lost connection, print dots
    delay(500);
    Serial.print(".");
    counter++;
    if(counter>=60){ //30 seconds timeout - reset board
    ESP.restart();
    }
  }

  // Reading temperature or humidity
  float t = dht.readTemperature(true);

  // Create a URL for the request
  String url = "https://groker.init.st/api/events?accessKey=";
  url += accesskey;
  url += "&bucketKey=";
  url += bucketkey;
  url += "&";
  url += signalname;
  url += "=";
  url += t;

  Serial.print("*** requesting URL");
 
  // ask.begin;
  ask.begin(url); //Specify the URL
  
  //Check for the returning code
  int httpCode = ask.GET();       

  Serial.print(httpCode);
   
  if (httpCode > 0) { 
      String payload = ask.getString();
  } else {
      Serial.println("Error on HTTP request");
  }
  ask.end(); //End 
  Serial.println("*** End ");
  delay(10000);    // delay
}