微信小程序esp32

### 微信小程序与ESP32交互开发指南 #### 1. 准备工作 为了使微信小程序能够与ESP32进行通信，通常采用MQTT协议作为中间件。EMQX是一个常用的MQTT服务器选项，可以部署在云端或本地环境中。 对于硬件部分，确保ESP32已安装并配置好Wi-Fi模块以便接入互联网，并通过Arduino IDE或其他IDE设置好固件以支持MQTT客户端功能[^1]。 #### 2. 配置ESP32 MQTT客户端 下面是一段简单的Arduino代码用于初始化ESP32上的MQTT客户端： ```cpp #include <WiFi.h> #include <PubSubClient.h> // WiFi credentials. const char* ssid = "your_SSID"; const char* password = "your_PASSWORD"; // MQTT Broker settings. const char* mqtt_server = "broker.emqx.io"; // EMQX broker address. WiFiClient espClient; PubSubClient client(espClient); void setup_wifi() { delay(10); Serial.println(); Serial.print("Connecting to "); Serial.println(ssid); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } randomSeed(micros()); Serial.println(""); Serial.println("WiFi connected"); Serial.println("IP address: "); Serial.println(WiFi.localIP()); } void reconnect() { // Loop until we're reconnected while (!client.connected()) { Serial.print("Attempting MQTT connection..."); // Attempt to connect if (client.connect("ESP32 Client")) { Serial.println("connected"); // Once connected, publish an announcement... client.publish("outTopic", "hello world"); // ... and resubscribe client.subscribe("inTopic"); } else { Serial.print("failed, rc="); Serial.print(client.state()); Serial.println(" try again in 5 seconds"); // Wait 5 seconds before retrying delay(5000); } } } ``` 这段代码实现了ESP32设备连接到指定的Wi-Fi网络以及MQTT代理的功能，并订阅了一个主题`inTopic`等待来自微信小程序的消息。 #### 3. 实现微信小程序端逻辑 接下来是在微信小程序中编写相应的页面处理函数来发送控制指令给ESP32。这里给出一个简化版的例子展示如何改变LED状态： ```javascript Page({ data: { LED1: false, }, onLoad(options){ const that = this; wx.connectSocket({ url: 'wss://broker.emqx.io:8084/mqtt', protocols: ['mqttv3.1'] }); wx.onSocketOpen(function(res) { console.log('WebSocket opened'); that.client = new Paho.MQTT.Client( "ws://broker.emqx.io:8084/mqtt", "clientId-" + Math.random().toString(16).substr(2, 8) ); let options = { onSuccess: () => {console.log("Connected")}, onFailure: () => {console.error("Failed")} }; that.client.connect(options); that.client.onMessageArrived = function(message){ console.log(`Received message on topic ${message.destinationName}: ${message.payloadString}`); }; }); changeLED1(event){ var ledStatus = event.detail.value ? '{"LED1":true}' : '{"LED1":false}'; this.setData({ LED1:event.detail.value }); this.client.send('/topic/ledControl', ledStatus ,{qos: 0,retain: false},function(err){ err || console.log("Command sent successfully."); }); } }); ``` 此脚本片段展示了如何建立Websocket连接至EMQX服务器并通过Paho库创建一个新的MQTT会话；当用户触发开关事件时，则向特定的主题发布一条消息告知ESP32更新其输出引脚的状态[^2]。