Failed to connect to Thingsboard Server - iot

Question

I am trying to monitor the temperature with dht22 and esp32 and send the data to the thingsboard. The Arduino sketch is as below:
\
#include "DHT.h"
#include <WiFi.h>
#include <ThingsBoard.h>
#define WIFI_SSID "*****"
#define WIFI_PASSWORD "******"
#define TOKEN "DHT22_TEMP"
// DHT
#define DHTPIN 2
#define DHTTYPE DHT22
char thingsboardServer[] = "demo.thingsboard.io";
WiFiClient wifiClient;
// Initialize DHT sensor.
DHT dht(DHTPIN, DHTTYPE);
ThingsBoard tb(wifiClient);
int status = WL_IDLE_STATUS;
unsigned long lastSend;
void setup()
{
Serial.begin(115200);
dht.begin();
delay(10);
InitWiFi();
lastSend = 0;
}
void loop()
{
if ( !tb.connected() ) {
reconnect();
}
if ( millis() - lastSend > 1000 ) { // Update and send only after 1 seconds
getAndSendTemperatureAndHumidityData();
lastSend = millis();
}
tb.loop();
}
void getAndSendTemperatureAndHumidityData()
{
Serial.println("Collecting temperature data.");
// Reading temperature or humidity takes about 250 milliseconds!
float humidity = dht.readHumidity();
// Read temperature as Celsius (the default)
float temperature = dht.readTemperature();
// Check if any reads failed and exit early (to try again).
if (isnan(humidity) || isnan(temperature)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
Serial.println("Sending data to ThingsBoard:");
Serial.print("Humidity: ");
Serial.print(humidity);
Serial.print(" %\t");
Serial.print("Temperature: ");
Serial.print(temperature);
Serial.println(" *C ");
tb.sendTelemetryFloat("temperature", temperature);
tb.sendTelemetryFloat("humidity", humidity);
}
void InitWiFi()
{
Serial.println("Connecting to AP ...");
// attempt to connect to WiFi network
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected to AP");
}
void reconnect() {
// Loop until we're reconnected
while (!tb.connected()) {
status = WiFi.status();
if ( status != WL_CONNECTED) {
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("Connected to AP");
}
Serial.print("Connecting to ThingsBoard node ...");
if ( tb.connect(thingsboardServer, TOKEN) ) {
Serial.println( "[DONE]" );
} else {
Serial.print( "[FAILED]" );
Serial.println( " : retrying in 5 seconds]" );
// Wait 5 seconds before retrying
delay( 5000 );
}
}
}
When this code is uploaded, it says:
"Connecting to ThingsBoard Server... [TB] Connection to server failed
[Failed] Retrying in 5 seconds"
I expect it to connect to thingsboard and send the data to it, Thingsboard is installed on-premise.

Answer 1

i never use thingsboar demo, i was using thingsboard cloud, to set up connection the server i use it like a define
#define TOKEN "YOUR_ACCESS_TOKEN"
#define THINGSBOARD_SERVER "demo.thingsboard.io"
all the rest must work, i will see again the example code from thingsboard example