// code for controlling servo motor using nodered dashboard
#include <WiFi.h>
#include <PubSubClient.h>
// Defining Pins
#define LED 2
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "test.mosquitto.org";// MQTT broker
WiFiClient espClient;
PubSubClient client(espClient);
long lastMsg = 0;
char msg[50];
int value = 0;
void setup() {
Serial.begin(115200);
setup_wifi();
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
pinMode(LED, OUTPUT);
//digitalWrite(3, HIGH);
}
void setup_wifi() {
delay(10);
Serial.println();
Serial.print("Connecting to ");
Serial.println(ssid);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("");
Serial.println("WiFi connected");
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
}
// Subscribe callback
void callback(char* topic, byte* payload, unsigned int length) {
Serial.print("Message arrived in topic: ");
Serial.println(topic);
Serial.print("Message: ");
String data = "";
for (int i = 0; i < length; i++) {
Serial.print((char)payload[i]);
data += (char)payload[i];
}
Serial.println();
Serial.print("Message size: ");
Serial.println(length);
Serial.println();
Serial.println("-----------------------");
Serial.println(data);
if (String(topic) == "/UWU_IOT/LED_Control") {
if (data == "ON") {
digitalWrite(LED, HIGH);
}
else {
digitalWrite(LED, LOW);
}
}
}
void reconnect() {
while (!client.connected()) {
Serial.print("Attempting MQTT connection...");
if (client.connect("ESPClient")) {
Serial.println("connected");
client.subscribe("/UWU_IOT/LED_Control");
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}}}
void loop() {
digitalWrite(3, HIGH);
if (!client.connected()) {
reconnect();
}
client.loop();
delay(100);
}