arduino mqtt esp32 code example
Example: esp32 arduino mqtt
#include <WiFi.h>
#include <PubSubClient.h>
// Replace the next variables with your SSID/Password combination
const char* ssid = "REPLACE_WITH_YOUR_SSID";
const char* password = "REPLACE_WITH_YOUR_PASSWORD";
// Add your MQTT Broker IP address, example:
//const char* mqtt_server = "192.168.1.144";
const char* mqtt_server = "YOUR_MQTT_BROKER_IP_ADDRESS";
WiFiClient espClient;
PubSubClient client(espClient);
void setup() {
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}
void setup_wifi() {
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
}
void callback(char* topic, byte* message, unsigned int length) {
// calback function for arrived message
Serial.print("Message arrived on topic: ");
Serial.print(topic);
Serial.print(". Message: ");
String messageTemp;
}
void reconnect() {
// Loop until we're reconnected
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
// Attempt to connect
if (client.connect("ESP8266Client")) {
Serial.println("connected");
// Subscribe
client.subscribe("esp32/output");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
// Wait 5 seconds before retrying
delay(5000);
}
}
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
// for publish
// client.publish("esp32/humidity", humString);
}