硬件入门 + 单片机基础（第21天）ESP32 全套项目联调-深圳市維司達科技有限公司

一、整体业务流程

DHT11/DHT22 温湿度传感器采集 → ESP32 WiFi 联网 → MQTT 三元组加密鉴权上云 → 云端物模型解析存储 → 云端历史数据归档生成曲线 → 云端下发指令 → ESP32 驱动继电器执行开关动作

二、硬件清单

ESP32 开发板
DHT11/DHT22 温湿度传感器
5V/3.3V 继电器模块
杜邦线若干

三、硬件接线

DHT11

VCC → 3.3V
GND → GND
DATA → GPIO4

继电器

VCC → 3.3V
GND → GND
IN → GPIO2

四、Arduino 库安装

WiFi自带
PubSubClientMQTT 客户端
AliyunIoTSDK阿里云官方加密联网库
DHT sensor library+Adafruit Unified Sensor温湿度库

五、完整整合源码（采集 + 上报 + 存储 + 远程控制一体）

#include <WiFi.h> #include <PubSubClient.h> #include <AliyunIoTSDK.h> #include "DHT.h" //===================== 配置区 自行修改 ===================== #define WIFI_SSID "你的WiFi名称" #define WIFI_PASSWORD "你的WiFi密码" #define PRODUCT_KEY "产品KEY" #define DEVICE_NAME "设备名称" #define DEVICE_SECRET "设备秘钥" #define REGION "cn-shanghai" #define DHTPIN 4 #define DHTTYPE DHT11 #define RELAY_PIN 2 #define UPLOAD_INTERVAL 3000 // 3秒上报一次 曲线平滑 //========================================================== DHT dht(DHTPIN,DHTTYPE); WiFiClient espClient; PubSubClient mqttClient(espClient); AliyunIoTSDK aliyunIot; bool relayState = false; float temp,humi; // 云端指令回调 远程控制继电器 void cloudCallback(char* topic,byte* payload,unsigned int len) { String recvData; for(int i=0;i<len;i++) recvData += (char)payload[i]; Serial.println("云端下发指令："+recvData); if(recvData.indexOf("DeviceSwitch\":true")>0) { relayState = true; digitalWrite(RELAY_PIN,HIGH); Serial.println("继电器开启"); } if(recvData.indexOf("DeviceSwitch\":false")>0) { relayState = false; digitalWrite(RELAY_PIN,LOW); Serial.println("继电器关闭"); } } // WiFi连接 void initWiFi() { WiFi.begin(WIFI_SSID,WIFI_PASSWORD); while(WiFi.status()!=WL_CONNECTED) { delay(500); Serial.print("."); } Serial.println("\nWiFi联网成功"); } // 阿里云MQTT加密连接 void initAliMQTT() { aliyunIot.connect(mqttClient,PRODUCT_KEY,DEVICE_NAME,DEVICE_SECRET,REGION); mqttClient.setCallback(cloudCallback); while(!mqttClient.connected()) { mqttClient.connect(DEVICE_NAME); delay(1000); } Serial.println("阿里云MQTT加密连接成功 设备已在线"); } // 采集温湿度 void getSensorData() { temp = dht.readTemperature(); humi = dht.readHumidity(); if(isnan(temp)||isnan(humi)) { Serial.println("传感器读取失败"); return; } } // 标准物模型JSON上报 void uploadToCloud() { char buf[256]; sprintf(buf,"{\"params\":{\"Temperature\":%.1f,\"Humidity\":%.1f,\"DeviceSwitch\":%s}}", temp,humi,relayState?"true":"false"); aliyunIot.postProperty(mqttClient,buf); Serial.println("数据上报："+String(buf)); } void setup() { Serial.begin(115200); pinMode(RELAY_PIN,OUTPUT); digitalWrite(RELAY_PIN,LOW); dht.begin(); initWiFi(); initAliMQTT(); } void loop() { mqttClient.loop(); // 断网重连机制 if(!mqttClient.connected()) initAliMQTT(); static unsigned long timeCnt = 0; if(millis()-timeCnt>=UPLOAD_INTERVAL) { timeCnt = millis(); getSensorData(); uploadToCloud(); } }