嵌入式开发在教育行业的应用

#include <WiFi.h>
#include <DHT.h>
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <PubSubClient.h>

// 定义引脚
#define DHTPIN 4          // DHT22 数据引脚连接到 GPIO 4
#define LDRPIN 34         // 光敏电阻连接到 GPIO 34
#define CO2PIN 32         // 二氧化碳传感器连接到 GPIO 32
#define RELAY_LIGHT 5     // 灯光继电器连接到 GPIO 5
#define RELAY_AC 18       // 空调继电器连接到 GPIO 18

// DHT 设置
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// OLED 显示屏设置
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Wi-Fi 设置
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// MQTT 设置
const char* mqtt_server = "mqtt.example.com";
WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  // 初始化串口
  Serial.begin(115200);
  
  // 初始化传感器
  dht.begin();
  pinMode(CO2PIN, INPUT);
  
  // 初始化继电器
  pinMode(RELAY_LIGHT, OUTPUT);
  pinMode(RELAY_AC, OUTPUT);

  // 初始化 OLED 显示屏
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.display();
  delay(2000);
  display.clearDisplay();
  
  // 连接 Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // 连接 MQTT 服务器
  client.setServer(mqtt_server, 1883);
}

void loop() {
  // 读取传感器数据
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  int lightIntensity = analogRead(LDRPIN);
  int co2Level = analogRead(CO2PIN); // 简单模拟二氧化碳浓度读取

  // 打印传感器数据
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %, Temperature: ");
  Serial.print(temperature);
  Serial.print(" *C, Light Intensity: ");
  Serial.print(lightIntensity);
  Serial.print(", CO2 Level: ");
  Serial.println(co2Level);

  // 控制灯光和空调
  if (lightIntensity < 300) {
    digitalWrite(RELAY_LIGHT, HIGH); // 开启灯光
  } else {
    digitalWrite(RELAY_LIGHT, LOW);  // 关闭灯光
  }

  if (temperature > 28.0) {
    digitalWrite(RELAY_AC, HIGH);    // 开启空调
  } else {
    digitalWrite(RELAY_AC, LOW);     // 关闭空调
  }

  // 将数据上传到云端 MQTT 服务器
  if (!client.connected()) {
    reconnect();
  }
  client.loop();

  String payload = String("Temperature: ") + temperature + " C, " + 
                   "Humidity: " + humidity + " %, " + 
                   "Light: " + lightIntensity + ", " + 
                   "CO2: " + co2Level;
  client.publish("classroom/environment", payload.c_str());

  // 在 OLED 显示屏上显示数据
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print("Temp: "); display.print(temperature); display.println(" C");
  display.print("Humidity: "); display.print(humidity); display.println(" %");
  display.print("Light: "); display.print(lightIntensity); display.println();
  display.print("CO2: "); display.print(co2Level); display.println();
  display.display();

  delay(2000); // 延时 2 秒
}

void reconnect() {
  while (!client.connected()) {
    if (client.connect("ESP32Client")) {
      client.subscribe("classroom/control");
    } else {
      delay(5000);
    }
  }
}