Node.js Arduino 串行监视器输入错误

Question

我正在尝试学习 Node.js，试图通过串行端口连接到一个工作的 Arduino 示例。代码如下:

var serialport = require("serialport"); // include the serialport library
var SerialPort = serialport.SerialPort; // localize object constructor

var express =   require('express'),
    app     =   express()
    , http  =   require('http')
    , server =  http.createServer(app)
    , io    =   require('socket.io').listen(server);

// listen for new web clients:
server.listen(8080);        

// open the serial port. Change the name to the name of your port, just like in Processing and Arduino:
var sp = new SerialPort("/dev/ttyACM0", { 
    // 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 (req, res) {
  res.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:  
    sp.on('data', function (data) {
        // set the value property of scores to the serial string:
        scores.value = data;
        // for debugging, you should see this in Terminal:
        console.log(data);
        // send a serialdata event to the web client:
        socket.emit('serialEvent', scores);
    });
});

代码成功执行，输出如下:

   info  - socket.io started
   debug - served static content /socket.io.js
   debug - client authorized
   info  - handshake authorized Yh2i5KCqhagEnCIK41q3
   debug - setting request GET /socket.io/1/websocket/Yh2i5KCqhagEnCIK41q3
   debug - set heartbeat interval for client Yh2i5KCqhagEnCIK41q3
   debug - client authorized for 
   debug - websocket writing 1::

然后，我在 Arduino 串行监视器中输入一些输入，我的 Node.js 脚本崩溃并出现以下错误:

/home/sisko/NodeJS/nodeSerialServer/serialServer.js:49
        scores.value = data;
        ^
ReferenceError: scores is not defined
    at SerialPort.<anonymous> (/home/sisko/NodeJS/nodeSerialServer/serialServer.js:49:3)
    at SerialPort.EventEmitter.emit (events.js:93:17)
    at parsers.readline (/home/sisko/NodeJS/nodeSerialServer/node_modules/serialport/serialport.js:36:17)
    at Array.forEach (native)
    at Object.parsers.readline [as parser] (/home/sisko/NodeJS/nodeSerialServer/node_modules/serialport/serialport.js:35:13)
    at process.nextTick.options.dataCallback (/home/sisko/NodeJS/nodeSerialServer/node_modules/serialport/serialport.js:89:15)
    at EventEmitter.emit (events.js:93:17)
    at ReadStream._emitData (fs.js:1365:10)
    at afterRead (fs.js:1347:10)
    at Object.wrapper [as oncomplete] (fs.js:362:17)

Answer 1

您需要定义分数变量并初始化它。

var express =   require('express'),
    app     =   express(),
    http  =   require('http'),
    server =  http.createServer(app),
    io    =   require('socket.io').listen(server),
    scores = {};