ESP32 Arduino 无法连接到 NodeJS SocketIO Web 套接字

Question

我正在尝试通过 Web 套接字将 ESP32 与本地 Nodejs 服务器连接。 我在 CLion 上使用 PlatformIO Arduino 环境（我不知道知道是否有用）。

ESP32成功连接了WiFi，也可以读取服务器页面的内容（我是测试的），但是似乎无法连接SocketIO websocket，我到处找了也没找到，我希望你能帮助我。

ESP32代码：

#include <Arduino.h>
#include <WebSocketsClient.h>
#include <HTTPClient.h>

WebSocketsClient websocket;
boolean connected = false

void webSocketEvent(WStype_t type, uint8_t * payload, size_t length) {
    switch(type) {
        case WStype_DISCONNECTED:
            Serial.printf("[WSc] Disconnected!\n");
            connected = false;
            break;
        case WStype_CONNECTED: 
            digitalWrite(MESSAGE_LED_PIN, HIGH);
            Serial.printf("[WSc] Connected to url: %s\n", payload);
            connected = true;
    }

void setup() {
    Serial.begin(115200);
    WiFi.begin("SSID", "PASSW");
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("");
    Serial.println("Connesso al WiFi");
    Serial.println(WiFi.localIP());
    inviaRichiestaHTTP(); // I don't enter the code of this function
    websocket.begin("192.168.1.16",3000,"/socket.io/?EIO=4");
    websocket.onEvent(webSocketEvent);
}

void loop() {
    websocket.loop();
}

系列：

....
Connesso al WiFi
192.168.1.170
[HTTP] Codice di stato: 200
<h1>Hello world</h1>
[WSc] Disconnected!
[WSc] Disconnected!
[WSc] Disconnected!

Nodejs 服务器：

const ip = require("ip");
var app = require('express')();
var server = require('http').createServer(app);
var io = require('socket.io')(server); //pass a http.Server instance
var port = process.env.PORT  80;

app.get('/', function (req, res) {
    //check sender ip
    var senderip = req.headers['x-forwarded-for']  req.connection.remoteAddress;
    console.log('sender ip: '+senderip);
   res.send('<h1>Hello world</h1>');
});

io.on('connection', function (socket) {
    console.log('Client connected');
    socket.on('message', function (data) {
        console.log('Message received: ', data);
    });
    socket.on('disconnect', function () {
        console.log('Client disconnected');
    });
});

server.listen(port);

Answer 1

如果我没记错的话，应该使用完整的 URL（包括协议）调用 websocket.begin() 方法。另外，您需要确保 WebSocket 连接使用 Socket.IO 服务器的正确路径。试试这个，看看是否有效，

// before update
websocket.begin("192.168.1.16", 3000, "/socket.io/?EIO=4");
// after update
websocket.begin("ws://192.168.1.16:3000/socket.io/?EIO=4"); // if you find that it doesn't work, you may want to try http:// for the WebSocket URL.