Smart Coffee Mug with Sensirion STS40 Temperature

#include <SensirionI2CSts4x.h>
#include <Wire.h>
#include <WiFi.h>
#include <WebServer.h>

// 🔹 REPLACE WITH YOUR WIFI CREDENTIALS 🔹
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

// 🔹 SETUP WEB SERVER ON PORT 80 🔹
WebServer server(80);

// 🔹 STS40 TEMPERATURE SENSOR SETUP 🔹
#define SDA_PIN 21
#define SCL_PIN 22
SensirionI2CSts4x Sts40;
float currentTemperature = 0.0;
float setTemperature = 50.0; // Default user-set temperature

// 🔹 RELAY PIN 🔹
#define RELAY_PIN 25  // Change to your actual GPIO pin

void setup() {
    Serial.begin(115200);
    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, LOW); // Ensure relay is off at start

    // 🔹 START I2C COMMUNICATION 🔹
    Wire.begin(SDA_PIN, SCL_PIN);
    Sts40.begin(Wire);

    // 🔹 CONNECT TO WIFI 🔹
    WiFi.begin(ssid, password);
    Serial.print("Connecting to Wi-Fi...");
    while (WiFi.status() != WL_CONNECTED) {
        delay(1000);
        Serial.print(".");
    }
    Serial.println("\nConnected!");
    Serial.print("ESP32 IP Address: ");
    Serial.println(WiFi.localIP());

    // 🔹 HANDLE WEB REQUESTS 🔹
    server.on("/setTemp", []() {
        if (server.hasArg("temp")) {
            setTemperature = server.arg("temp").toFloat();
            Serial.print("Set Temperature Updated: ");
            Serial.println(setTemperature);
            server.send(200, "application/json", "{\"status\":\"success\"}");
        } else {
            server.send(400, "application/json", "{\"status\":\"error\",\"message\":\"No temp parameter\"}");
        }
    });

    server.on("/getTemp", []() {
        String tempJson = "{\"temperature\": " + String(currentTemperature) + "}";
        server.send(200, "application/json", tempJson);
    });

    server.begin();
    Serial.println("HTTP Server Started");
}

void loop() {
    server.handleClient();

    // 🔹 READ STS40 TEMPERATURE 🔹
    float temperature;
    uint16_t error = Sts40.measureHighPrecision(temperature);
    if (!error) {
        currentTemperature = temperature;
        Serial.print("Current Temperature: ");
        Serial.println(currentTemperature);
    } else {
        Serial.println("STS40 Sensor Error!");
    }

    // 🔹 CONTROL RELAY 🔹
    if (currentTemperature < setTemperature) {
        digitalWrite(RELAY_PIN, HIGH); // Turn ON warming pad
        Serial.println("Warming pad ON");
    } else {
        digitalWrite(RELAY_PIN, LOW);  // Turn OFF warming pad
        Serial.println("Warming pad OFF");
    }

    delay(2000);
}