I am using PubSubClient library to subscribe to a server using a nodemcu. I tested the code using cloudMQTT and MQTTlens and it worked fine. In addition to that, I used MQTTlens to check mqtt connection with my pc. In there, I did not specify username and password (I kept blank) and it worked just fine. When I want to connect for a public server (ex: "tcp://11.111.111.111"), does not connect.
code for nodemcu
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
const char* ssid = "*****";
const char* password = "****";
const char* mqttServer = "****";
const int mqttPort = 1883;
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.println("Connecting to WiFi..");
}
Serial.println("Connected to the WiFi network");
client.setServer(mqttServer, mqttPort);
client.setCallback(callback);
while (!client.connected()) {
Serial.println("Connecting to MQTT...");
if (client.connect("ESP8266Client")) {
Serial.println("connected");
} else {
Serial.print("failed with state ");
Serial.print(client.state());
delay(2000);
}
}
client.publish("topic1", "Hello from ESP8266_tester1");
client.subscribe("topic1");
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived in topic: ");
Serial.println(topic);
Serial.print("Message:");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
Serial.println("-----------------------");
}
void loop() {
client.loop();
}
the result from the serial monitor
Any suggestion is welcome
The problem was with the ip I have provided. IP does not require "tcp://" part. After removing that, the code worked well.