#include <WiFi.h>
#include "PubSubClient.h"
//1-configuration du point d accés
const char* ssid = "Wokwi-GUEST";
const char* password = "";
//2-configuration du broker EMQX PORT 1883
const char* mqttServer = "broker.emqx.io";
int port = 1883;
//3-configuration d un clien mqtt (subscriber)
WiFiClient espClient;
PubSubClient client(espClient);//subscriber
const int seuil=1;
const int Buzzer = 2;
char clientId[50];
void setup() {
Serial.begin(115200);
Serial.println("Connecting to ");
Serial.println(ssid);
pinMode(Buzzer, OUTPUT);
wifiConnect();
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
//4-associer le broker au client (subscriber)
client.setServer(mqttServer, port);
//5-l appel de la fonction callback pour lire la valeur
client.setCallback(callback);
}
void wifiConnect() {
WiFi.mode(WIFI_STA); //type du wifi=sta
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
}
void mqttReconnect() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
//attribuer un id aleatoire au client
long r = random(1000);
sprintf(clientId, "clientId-%ld", r);
if (client.connect(clientId)) {
Serial.print(clientId);
Serial.println(" connected");
//connexion au topic
client.subscribe("topic_sensor_temperature");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
//lire le topic
void callback(char* topic, byte* message, unsigned int length) {
String msg = String((char*)message).substring(0, length);
if (msg == "1") {
digitalWrite(Buzzer, HIGH);
tone(2,262, 250); // Activer le buzzer
Serial.println("Alerte : Température élevée !");
delay(2000);
} else{
Serial.println("etat ok");
digitalWrite(Buzzer, LOW);
delay(2000);
}
}
void loop() {
delay(10);
if (!client.connected()) {
mqttReconnect();
}
client.loop();
}