#include <WiFi.h>
#include <PubSubClient.h>
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "192.168.29.251";
WiFiClient espClient;
PubSubClient client(espClient);
const char* relayTopic = "roomone";
int relayPins[] = {2, 3, 4, 5};
int numRelays = 4;
void setup() {
Serial.begin(115200);
setupWiFi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
for (int i = 0; i < numRelays; i++) {
pinMode(relayPins[i], OUTPUT);
}
}
void loop() {
if (!client.connected()) {
reconnect();
}
client.loop();
}
void callback(char* topic, byte* payload, unsigned int length) {
String relayCommand = String(payload[0]);
int relayNum = relayCommand.toInt();
if (relayNum >= 1 && relayNum <= numRelays) {
digitalWrite(relayPins[relayNum - 1], !digitalRead(relayPins[relayNum - 1]));
Serial.print("Toggled Relay ");
Serial.println(relayNum);
}
}
void setupWiFi() {
delay(10);
Serial.println("\nConnecting to WiFi");
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\nConnected to WiFi");
}
void reconnect() {
while (!client.connected()) {
Serial.println("Connecting to MQTT...");
if (client.connect("ESP32Client","HomeS","serverone")) {
Serial.println("Connected to MQTT");
client.subscribe(relayTopic);
} else {
Serial.print("Failed, rc=");
Serial.print(client.state());
Serial.println(" Trying again in 5 seconds...");
delay(5000);
}
}
}