Question

我正在创建一个需要从串口读取数据的应用程序，添加到队列的BACK中，然后从队列的FRONT通过socket.io发出。

我的示例代码（到目前为止未经测试）是：

//includes
var http = require('http'),
io = require('socket.io'),
serialport = require('serialport'),
listish = require('listish');

//initialize serial
var portname = '/devttyACM0';
var sp = new serialport();
sp.open(portname, {
    baudrate: 9600,
    databits: 8,
    parity: 'none',
    stopbits: 1,
    flowcontrol: false
});

//initialize socket.io
io.sockets.on('connection', function(socket){
    socket.on('msg', function(msg){
        console.log(msg);
    });
    socket.on('disconnect', function(){
        console.log('disconnected');
    });
}).listen(8888);

//initialize queue
var queue = new listish();

//enqueue all data received on the serial port
sp.on('data', function(data){
    queue.enqueue(data.tostring());
})

//emit all data from the FRONT of the queue
io.sockets.emit('msg', queue.dequeue());

将数据排入队列的部分基本上可以，因为它是异步的。当在串行端口上接收数据时，则对其进行处理（入队）。

我想要的是'发射'独立于其他一切发生。也就是说，只要队列中有数据，就必须运行。

Answer 1

这是一个草稿，没有测试过，让我知道它是否有效！

//includes
var http = require('http'),
io = require('socket.io'),
serialport = require('serialport'),
listish = require('listish');

//initialize serial
var portname = '/devttyACM0';
var sp = new serialport();
sp.open(portname, {
    baudrate: 9600,
    databits: 8,
    parity: 'none',
    stopbits: 1,
    flowcontrol: false
});

//initialize socket.io
io.sockets.on('connection', function(socket){
    socket.on('msg', function(msg){
        console.log(msg);
    });
    socket.on('disconnect', function(){
        console.log('disconnected');
    });
    socket.on('requestingData', function(){
      var msg = queue.dequeue();
      if(msg === "" || msg === [] || msg === null){
        return false; // don't send 'msg' with no msg
      };
      // emit all data from the FRONT of the queue to all clients
      io.sockets.emit('msg', msg);

      // Or to only send msg to the socket that requested the data this time:
      // socket.emit('msg', queue.dequeue());
    });
}).listen(8888);

//initialize queue
var queue = new listish();

//enqueue all data received on the serial port
sp.on('data', function(data){
    queue.enqueue(data.tostring());
})

// ***client.js***
socket = io.connect('http://localhost:8888');
socket.on('connect', function(){
  alert('Connected! Check F12 console');
});
socket.on('msg', function(data){
  $('<div></div>').text(data)
  .appendTo($(document));
});

window.setInterval(
function(){
  socket.emit('requestingData');
}
, 200); // in ms

Node.js并发函数

1 个答案: