node.js - Nodejs Websocket server with EP32 client

Question

MY ESP32 client code is,

#include <WiFi.h>
#include <WebSocketClient.h>
 
const char* ssid     = "###";
const char* password = "###";
 
char path[] = "/";
char host[] = "192.##.##.##";
 
WebSocketClient webSocketClient;
WiFiClient client;

void connnect(){
   if (client.connect(host, 5000)) {
    Serial.println("Connected");
  } else {
    Serial.println("Connection failed.");
  }
 
  webSocketClient.path = path;
  webSocketClient.host = host;
  if (webSocketClient.handshake(client)) {
    Serial.println("Handshake successful");
  } else {
    Serial.println("Handshake failed.");
  }
}
void setup() {
  Serial.begin(115200);
 
  WiFi.begin(ssid, password);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
 
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
 
  delay(5000);
 
 connnect();
 
}
 
void loop() {
  String data;
 
  if (client.connected()) {
 
    webSocketClient.sendData("Info to be echoed back");
 
    webSocketClient.getData(data);
    if (data.length() > 0) {
      Serial.print("Received data: ");
      Serial.println(data);
    }
 
  } else {
    Serial.println("Client disconnected.");
    connnect();
  }
 
  delay(3000);
 
}

My websocket server running in Nodejs is,

var WebSocketServer = require('websocket').server;
var http = require('http');

var server = http.createServer(function(request, response) {
    console.log((new Date()) + ' Received request for ' + request.url);
    response.writeHead(404);
    response.end();
});
server.listen(5000, function() {
    console.log((new Date()) + ' Server is listening on port 5000');
});

wsServer = new WebSocketServer({
    httpServer: server,
    // You should not use autoAcceptConnections for production
    // applications, as it defeats all standard cross-origin protection
    // facilities built into the protocol and the browser.  You should
    // *always* verify the connection's origin and decide whether or not
    // to accept it.
    autoAcceptConnections: false
});

function originIsAllowed(origin) {
  // put logic here to detect whether the specified origin is allowed.
  return true;
}

wsServer.on('request', function(request) {
    console.log(request)
    if (!originIsAllowed(request.origin)) {
      // Make sure we only accept requests from an allowed origin
      request.reject();
      console.log((new Date()) + ' Connection from origin ' + request.origin + ' rejected.');
      return;
    }
    
    var connection = request.accept('echo-protocol', request.origin);
    console.log((new Date()) + ' Connection accepted.');
    connection.on('message', function(message) {
        if (message.type === 'utf8') {
            console.log('Received Message: ' + message.utf8Data);
            connection.sendUTF(message.utf8Data);
        }
        else if (message.type === 'binary') {
            console.log('Received Binary Message of ' + message.binaryData.length + ' bytes');
            connection.sendBytes(message.binaryData);
        }
    });
    connection.on('close', function(reasonCode, description) {
        console.log((new Date()) + ' Peer ' + connection.remoteAddress + ' disconnected.');
    });
});

When I run both the codes the error I receive is,

Error: Specified protocol was not requested by the client.

What I need is to run a websocket server on nodejs where ESP32 can connect as a client to send and receive data. Please show me what I have done wrong, be cause there are more than on error in the above code. If there any simple and better suggestions to code ESP32 and the server please suggest me that. Thanks in advance

question from:https://stackoverflow.com/questions/65857165/nodejs-websocket-server-with-ep32-client

Answer 1

I found the answer to the problem. replace request.accept('echo-protocol', request.origin) with request.accept(null, request.origin)