#include <WiFi.h>
#include <MQTT.h>
const char ssid[] = "Wokwi-GUEST";
const char pass[] = "";
WiFiClient net;
MQTTClient client;
unsigned long lastMillis = 0; //gunakan millis supaya tidak tabrakan
void connect() {
Serial.print("checking wifi...");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(1000);
}
Serial.print("\nconnecting...");
while (!client.connect("perangkat1")) { //clientID bisa diubah sesuai perangkat
//while (!client.connect("arduino", "public", "public")) {
Serial.print(".");
delay(1000);
}
Serial.println("\nconnected!");
client.subscribe("esp32/belajar/sub");
// client.unsubscribe("/hello");
}
void messageReceived(String &topic, String &payload) {
Serial.println("incoming: " + topic + " - " + payload);
// Note: Do not use the client in the callback to publish, subscribe or
// unsubscribe as it may cause deadlocks when other things arrive while
// sending and receiving acknowledgments. Instead, change a global variable,
// or push to a queue and handle it in the loop after calling `client.loop()`.
}
void setup() {
Serial.begin(115200);
WiFi.begin(ssid, pass);
// Note: Local domain names (e.g. "Computer.local" on OSX) are not supported
// by Arduino. You need to set the IP address directly.
client.begin("broker.emqx.io", net);
client.onMessage(messageReceived); //kita mau publish
connect();
}
void loop() {
client.loop();
delay(10); // <- fixes some issues with WiFi stability
if (!client.connected()) {
connect();
}
// publish a message roughly every second.
if (millis() - lastMillis > 1000) {
lastMillis = millis();
client.publish("belajar/iot", "halo");
}
}