Hi everybody,
Taking advantage of staying at home...
I am trying the example Pubsubclient mqtt_esp8266 in order to publish and suscribe some topic through Node-RED. However I am not able to connect to broker, It shows me always the same failure:
Attempting MQTT connection...failed, rc=-2 try again in 5 seconds
I wanted to learn the basic program to publish and suscribe, I installed the mosquitto broker and also Node-RED.
This is the code:
*/
#include <ESP8266WiFi.h>
#include <PubSubClient.h>
// Update these with values suitable for your network.
const char* ssid = "WLAN_2G";
const char* password = "password";
const char* mqtt_server = "XXX.XXX.X.XXX";
WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
void setup_wifi() {
delay(10);
// We start by connecting to a WiFi network
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
randomSeed(micros());
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived [");
Serial.print(topic);
Serial.print("] ");
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
}
Serial.println();
// Switch on the LED if an 1 was received as first character
if ((char)payload[0] == '1') {
digitalWrite(BUILTIN_LED, LOW); // Turn the LED on (Note that LOW is the voltage level
// but actually the LED is on; this is because
// it is active low on the ESP-01)
} else {
digitalWrite(BUILTIN_LED, HIGH); // Turn the LED off by making the voltage HIGH
}
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Create a random client ID
String clientId = "ESP8266Client-";
clientId += String(random(0xffff), HEX);
// Attempt to connect
if (client.connect(clientId.c_str())) {
Serial.println("connected");
// Once connected, publish an announcement...
client.publish("outTopic", "hello world");
// ... and resubscribe
client.subscribe("inTopic");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void setup() {
pinMode(BUILTIN_LED, OUTPUT); // Initialize the BUILTIN_LED pin as an output
Serial.begin(9600);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
long now = millis();
if (now - lastMsg > 2000) {
lastMsg = now;
++value;
snprintf (msg, 50, "hello world #%ld", value);
Serial.print("Publish message: ");
Serial.println(msg);
client.publish("outTopic", msg);
}
}
For mqtt_server, I understand that i have to introduced the IPv4, because i have mosquitto running in my computer.
However when i start Node-RED, the console shows:
22 Apr 08:32:48 - [info] Starting flows
22 Apr 08:32:48 - [info] Started flows
22 Apr 08:32:48 - [info] [mqtt-broker:XXXXXX80.9xxxX] Connected to broker: ESP8266Client-@mqtt://localhost:1883
22 Apr 09:32:47 - [info] Stopping flows
22 Apr 09:32:47 - [info] [mqtt-broker:XXXXXX80.9xxxX] Disconnected from broker: ESP8266Client-@mqtt://localhost:1883
22 Apr 09:32:47 - [info] Stopped flows
22 Apr 09:32:47 - [info] Starting flows
22 Apr 09:32:47 - [info] Started flows
22 Apr 09:32:47 - [info] [mqtt-broker:XXXXXX80.9xxxX] Connected to broker: ESP8266Client-@mqtt://localhost:1883
Could you please help me to find the mistake?? I would be very grateful.
Thanks so much.