Question

在webSocket.sendTXT(num, "Connected");中或在代码中使用的任何其他地方 num 的目的是什么，它服务的功能是什么？因为它并没有被定义为任何地方，但它是必需的作为函数参数传递给它工作。

在void webSocketEvent(uint8_t num, WStype_t type, uint8_t * payload, size_t length)中将其设置为函数参数。

Links2004/arduinoWebSockets Library

/*
 * WebSocketServer_LEDcontrol.ino
 *
 *  Created on: 26.11.2015
 *
 */

#include <Arduino.h>

#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <WebSocketsServer.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
#include <Hash.h>

#define LED_RED     15
#define LED_GREEN   12
#define LED_BLUE    13

#define USE_SERIAL Serial


ESP8266WiFiMulti WiFiMulti;

ESP8266WebServer server = ESP8266WebServer(80);
WebSocketsServer webSocket = WebSocketsServer(81);

void webSocketEvent(uint8_t num, WStype_t type, uint8_t * payload, size_t length) {

    switch(type) {
        case WStype_DISCONNECTED:
            USE_SERIAL.printf("[%u] Disconnected!\n", num);
            break;
        case WStype_CONNECTED: {
            IPAddress ip = webSocket.remoteIP(num);
            USE_SERIAL.printf("[%u] Connected from %d.%d.%d.%d url: %s\n", num, ip[0], ip[1], ip[2], ip[3], payload);

            // send message to client
            webSocket.sendTXT(num, "Connected");
        }
            break;
        case WStype_TEXT:
            USE_SERIAL.printf("[%u] get Text: %s\n", num, payload);

            if(payload[0] == '#') {
                // we get RGB data

                // decode rgb data
                uint32_t rgb = (uint32_t) strtol((const char *) &payload[1], NULL, 16);

                analogWrite(LED_RED,    ((rgb >> 16) & 0xFF));
                analogWrite(LED_GREEN,  ((rgb >> 8) & 0xFF));
                analogWrite(LED_BLUE,   ((rgb >> 0) & 0xFF));
            }

            break;
    }

}

void setup() {
    //USE_SERIAL.begin(921600);
    USE_SERIAL.begin(115200);

    //USE_SERIAL.setDebugOutput(true);

    USE_SERIAL.println();
    USE_SERIAL.println();
    USE_SERIAL.println();

    for(uint8_t t = 4; t > 0; t--) {
        USE_SERIAL.printf("[SETUP] BOOT WAIT %d...\n", t);
        USE_SERIAL.flush();
        delay(1000);
    }

    pinMode(LED_RED, OUTPUT);
    pinMode(LED_GREEN, OUTPUT);
    pinMode(LED_BLUE, OUTPUT);

    digitalWrite(LED_RED, 1);
    digitalWrite(LED_GREEN, 1);
    digitalWrite(LED_BLUE, 1);

    WiFiMulti.addAP("SSID", "passpasspass");

    while(WiFiMulti.run() != WL_CONNECTED) {
        delay(100);
    }

    // start webSocket server
    webSocket.begin();
    webSocket.onEvent(webSocketEvent);

    if(MDNS.begin("esp8266")) {
        USE_SERIAL.println("MDNS responder started");
    }

    // handle index
    server.on("/", []() {
        // send index.html
        server.send(200, "text/html", "<html><head><script>var connection = new WebSocket('ws://'+location.hostname+':81/', ['arduino']);connection.onopen = function () {  connection.send('Connect ' + new Date()); }; connection.onerror = function (error) {    console.log('WebSocket Error ', error);};connection.onmessage = function (e) {  console.log('Server: ', e.data);};function sendRGB() {  var r = parseInt(document.getElementById('r').value).toString(16);  var g = parseInt(document.getElementById('g').value).toString(16);  var b = parseInt(document.getElementById('b').value).toString(16);  if(r.length < 2) { r = '0' + r; }   if(g.length < 2) { g = '0' + g; }   if(b.length < 2) { b = '0' + b; }   var rgb = '#'+r+g+b;    console.log('RGB: ' + rgb); connection.send(rgb); }</script></head><body>LED Control:<br/><br/>R: <input id=\"r\" type=\"range\" min=\"0\" max=\"255\" step=\"1\" oninput=\"sendRGB();\" /><br/>G: <input id=\"g\" type=\"range\" min=\"0\" max=\"255\" step=\"1\" oninput=\"sendRGB();\" /><br/>B: <input id=\"b\" type=\"range\" min=\"0\" max=\"255\" step=\"1\" oninput=\"sendRGB();\" /><br/></body></html>");
    });

    server.begin();

    // Add service to MDNS
    MDNS.addService("http", "tcp", 80);
    MDNS.addService("ws", "tcp", 81);

    digitalWrite(LED_RED, 0);
    digitalWrite(LED_GREEN, 0);
    digitalWrite(LED_BLUE, 0);

}

void loop() {
    webSocket.loop();
    server.handleClient();
}

Answer 1

Looking at the library's source code，它显示它是客户端ID，因此您可以区分同时连接的多个客户端。

/*
 * send text data to client
 * @param num uint8_t client id
 * @param payload uint8_t *
 * @param length size_t
 * @param headerToPayload bool  (see sendFrame for more details)
 * @return true if ok
 */
bool WebSocketsServer::sendTXT(uint8_t num, uint8_t * payload, size_t length, bool headerToPayload) {
    if(num >= WEBSOCKETS_SERVER_CLIENT_MAX) {
        return false;
    }
    if(length == 0) {
        length = strlen((const char *) payload);
    }
    WSclient_t * client = &_clients[num];
    if(clientIsConnected(client)) {
        return sendFrame(client, WSop_text, payload, length, false, true, headerToPayload);
    }
    return false;
}

什么是＆＃34; num＆＃34;的目的？在arduinoWebSockets？

1 个答案: