#include <WiFi.h>
#include <PubSubClient.h>
#define ledbiru 2
#define ledungu 4
#define ledorange 5
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const char* mqtt_server = "broker.hivemq.com";
const int mqtt_port = 1883;
const char* topicMQTT = "thara/ledht";
WiFiClient espClient;
PubSubClient clientMQTT(espClient);
void connectToInternet();
void setupMQTT();
void reconnectMQTT();
void setup() {
pinMode(ledbiru, OUTPUT);
pinMode(ledungu, OUTPUT);
pinMode(ledorange, OUTPUT);
Serial.begin(115200);
connectToInternet();
setupMQTT();
clientMQTT.setCallback(callback);
}
void connectToInternet() {
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.print("IP Address: ");
Serial.println(WiFi.localIP());
}
void setupMQTT() {
clientMQTT.setServer(mqtt_server, mqtt_port);
}
void reconnectMQTT() {
while (!clientMQTT.connected()) {
Serial.print("Attempting MQTT connection...");
String clientId = "ESP32Client-";
clientId += String(random(0xffff), HEX);
if (clientMQTT.connect(clientId.c_str())) {
Serial.println("connected");
clientMQTT.subscribe(topicMQTT);
} else {
Serial.print("failed, rc=");
Serial.print(clientMQTT.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}
void callback(char* topic, byte* message, unsigned int length) {
Serial.print("Message arrived on topic: ");
Serial.print(topic);
String messageTemp;
for (int i = 0; i < length; i++) {
messageTemp += (char)message[i];
}
Serial.println("Message: " + messageTemp);
if (String(topic) == topicMQTT) {
float temperature = parseTemperature(messageTemp);
controlLEDs(temperature);
}
}
float parseTemperature(String message) {
int startIndex = message.indexOf("Temperature: ") + 13;
int endIndex = message.indexOf("C");
String tempString = message.substring(startIndex, endIndex);
return tempString.toFloat();
}
void controlLEDs(float temperature) {
if (temperature < 20) {
digitalWrite(ledbiru, HIGH);
digitalWrite(ledungu, LOW);
digitalWrite(ledorange, LOW);
Serial.println("Warning: Temperature below 20°C");
} else if (temperature > 23) {
digitalWrite(ledbiru, LOW);
digitalWrite(ledungu, HIGH);
digitalWrite(ledorange, LOW);
Serial.println("Danger: Temperature above 23°C");
} else {
digitalWrite(ledbiru, LOW);
digitalWrite(ledungu, LOW);
digitalWrite(ledorange, HIGH);
Serial.println("Normal: Temperature between 20°C and 23°C");
}
}
void loop() {
if (!clientMQTT.connected()) {
reconnectMQTT();
}
clientMQTT.loop();
}