Question

我正在使用node.js创建一个引入串行数据的服务器。串行数据在HTML中成功显示;但是，我想创建一个可以保存数据的'var'。请有人帮忙吗？

这是我的index.html页面：

<!DOCTYPE html>
<html>
    <head>
    <script src="/socket.io/socket.io.js"></script>

    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.2/jquery.min.js"></script>

    <script>

        // open a connection to the serial server:
        var socket = io.connect('http://localhost:8080');

         // when you get a serialdata event, do this:
        socket.on('serialEvent', function (data) {
            // look for the textDisplay element in the HTML below:
            var element = document.getElementById('IDTag');
            // set the stuff inside the element's HTML tags to
            // whatever the 'value' property of the received data is:
            element.innerHTML = data.value;

            });

  </script>
    </head>
    <body>
    And the latest is:
    <div id="IDTag">The RFID Tag ID will show here.</div>   
    </body>
</html>

这是我的SerialServer.js doc：

/*
    serialServer.js
    a node.js app to read serial strings and send them to webSocket clients
    requires:
        * node.js (http://nodejs.org/)
        * express.js (http://expressjs.com/)
        * socket.io (http://socket.io/#how-to-use)
        * serialport.js (https://github.com/voodootikigod/node-serialport)

    based on the core examples for socket.io and serialport.js

    created 21 Aug 2012
    modified 14 Oct 2012
    by Tom Igoe

    Patches and improvements suggested by Steve Klise, Lia Martinez, and Will Jennings

*/


var serialport = require("serialport"),             // include the serialport library
    SerialPort  = serialport.SerialPort,            // make a local instance of serial
    app = require('express')(),                     // start Express framework
    server = require('http').createServer(app),     // start an HTTP server
    io = require('socket.io').listen(server);       // filter the server using socket.io

var serialData = {};                                // object to hold what goes out to the client

server.listen(8080);                                // listen for incoming requests on the server

console.log("Listening for new clients on port 8080");

// open the serial port. Change the name to the name of your port, just like in Processing and Arduino:
var myPort = new SerialPort("/dev/tty.usbmodemfa131", { 
    // look for return and newline at the end of each data packet:
    parser: serialport.parsers.readline("\r\n") 
});

// respond to web GET requests with the index.html page:
app.get('/', function (request, response) {
  response.sendfile(__dirname + '/index.html');
});

// listen for new socket.io connections:
io.sockets.on('connection', function (socket) {
    // if there's a socket client, listen for new serial data:  
    myPort.on('data', function (data) {
        // set the value property of scores to the serial string:
        serialData.value = data;
        // for debugging, you should see this in Terminal:
        console.log(data);
        // send a serial event to the web client with the data:
        socket.emit('serialEvent', serialData);
    });
});

提前致谢！

Answer 1

首先，我建议将所有的javascript移动到页面的末尾，在结束的body标签之前（而不是head标签）。

其次，我发现你在同一个端口上运行socket.io服务器和http服务器很奇怪。

我甚至不确定这是运行socket.io的正确方法，我建议改为使用官方演示（它们可以保证工作）。

将值记录到放置在HTML中的控制台中

1 个答案: