### Project 34 Smart Home **1. Description** In this project, we simulate the smart home with the inventor kit. **Notes** 1. You need to prepare your a 2.4GHz frequency WIFI, not 5GHz frequency. It can be a mobile hotspot or a router. 2. The ESP32 board consumes more power when connected to the network, so you need to connect an external power supply to this kit. We provide you with a 6XAA Battery Holder (battery not included), which you can connect to the DC port of the ESP32 integrated board. ![](media/B62.png)![](media/B63.png) 3. When using other devices to control this kit, the ESP32 board needs to be connected to the same network as your control device. 4. Remember your wifi network name and password and fill it into the code before uploading it. ``` const char* ssid = "your_SSID"; // Fill in WiFi name, for example,= "KEYES" const char* password = "your_password"; // Fill in WiFi password, for example,= "123456" ``` **2. Wiring Diagram** ![](media/B64.png) **3. Upload Code** ``` #include #include #include #include LiquidCrystal_I2C lcd(0x27, 16, 2); // WiFi configuration const char* ssid = "your-SSID"; // your WiFi name const char* password = "your-PASSWORD"; // your WiFi password // DHT11 configuration xht11 xht(26); //set DHT11 sensor pin to IO26 unsigned char dat[] = { 0, 0, 0, 0 }; //Define an array to store temperature and humidity values int i = 0; // photoresistor analog pin #define LDR_PIN 34 // connect the photoresistor to GPIO 34 // LED pins #define redLED_PIN 12 #define yellowLED_PIN 13 #define greenLED_PIN 14 #define blueLED_PIN 15 // LED state bool redLEDState = false; bool yellowLEDState = false; bool greenLEDState = false; bool blueLEDState = false; // Web server AsyncWebServer server(80); String generateHTML() { String html = ""; html += ""; // Automatically refresh every 5 seconds html += ""; // temperature html += "

Sensor Data

"; html += "

Temperature

"; html += "

" + String(dat[2]) + " °C

"; html += "

"; // humidity html += "

"; html += "

Humidity

"; html += "

" + String(dat[0]) + " %

"; html += "

"; // diaplay photoresistor resistance value int lightValue = analogRead(LDR_PIN); // photoresistor value html += "

"; html += "

Luminance

"; html += "

" + String(lightValue) + "

"; html += "

"; // LED control button html += "

Control LEDs

"; html += ""; html += ""; html += ""; html += ""; // JavaScript control LED On/Off html += ""; html += ""; return html; } void setup() { // Initialize serial port Serial.begin(115200); lcd.init(); // initialize the lcd lcd.backlight(); lcd.setCursor(0, 0); lcd.print("IP:"); // WiFi connection WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { lcd.setCursor(i, 1); lcd.print("."); delay(500); i++; if (i > 15) { i = 0; lcd.setCursor(0, 1); lcd.print(" "); } } lcd.setCursor(0, 1); lcd.print(" "); lcd.setCursor(0, 1); lcd.print(WiFi.localIP()); // Set LED pins to output pinMode(redLED_PIN, OUTPUT); pinMode(yellowLED_PIN, OUTPUT); pinMode(greenLED_PIN, OUTPUT); pinMode(blueLED_PIN, OUTPUT); // Process Web requests server.on("/", HTTP_GET, [](AsyncWebServerRequest* request) { if (!xht.receive(dat)) { Serial.println("sensor error"); } String html = generateHTML(); request->send(200, "text/html", html); }); // Control the end of the LED server.on("/toggle", HTTP_GET, [](AsyncWebServerRequest* request) { String led = request->getParam("led")->value(); int ledNum = led.toInt(); if (ledNum == 0) { redLEDState = !redLEDState; digitalWrite(redLED_PIN, redLEDState ? HIGH : LOW); // LED 1 } else if (ledNum == 1) { yellowLEDState = !yellowLEDState; digitalWrite(yellowLED_PIN, yellowLEDState ? HIGH : LOW); // LED 2 } else if (ledNum == 2) { greenLEDState = !greenLEDState; digitalWrite(greenLED_PIN, greenLEDState ? HIGH : LOW); // LED 3 } else if (ledNum == 3) { blueLEDState = !blueLEDState; digitalWrite(blueLED_PIN, blueLEDState ? HIGH : LOW); // LED 4 } request->redirect("/"); // Go back to home page }); // Start the Web server server.begin(); } void loop() { // Read the temperature and humidity values and update the web page if (!xht.receive(dat)) { Serial.println("sensor error"); } delay(2000); // Refresh the page every 2 seconds } ``` **4. Test Result** After uploading the code, LCD1602 shows the IP address. Open the browser, enter the IP address and you will see the control page. At this time, you can use the control device to read the value read by the sensor, and you can also control the on and off of the LED. ![](media/B65.jpg)