在nodejs中傳遞的javascript消息

Question

任何人都可以請幫助我如何做到這一點？我想從WebSocket的每一次將消息傳遞給串口我收到一條消息

var firmata = require('firmata'); 
var board = new firmata.Board('COM4'); 

var WebSocketServer = require('ws').Server; 
var wss = new WebSocketServer({ port: 8081 }); 

wss.on('connection', function connection(websocket) { 
    websocket.on('message', function incoming(message) { 
    board.servoWrite(5, message); //This doesn't work but how do i send? 
} 

board.on("ready", function() { 
    board.servoWrite(5, 0); // this works but i need the message from above which I cant access. 

}); 

Answer 1

它不是一個錯誤的語法時才..不得不添加

board.servoConfig(5, 0, 30); 

我補充它在這樣的代碼：

var firmata = require('firmata'); 
var board = new firmata.Board('COM4',function(){ 

}); 

var WebSocketServer = require('ws').Server; 
var wss = new WebSocketServer({ port: 8081 }); 

wss.on('connection', function connection(websocket) { 
    websocket.on('message', function incoming(message) { 
    board.servoConfig(5, 0, 30); 
    board.servoWrite(5, message); //This doesn't work but how do i send? 
} 

board.on("ready", function() { 
    board.servoWrite(5, 0); // this works but i need the message from above which I cant access. 

}); 

Answer 2

您應該添加的偵聽器之後board已準備就緒。

board.on("ready", function() { 
    wss.on('connection', function connection(websocket) { 
     websocket.on('message', function incoming(message) { 
      board.servoWrite(5, message); 
     }); 
    }); 
}); 

無論是或聲明一個變量，告訴你它是否準備就緒。

var isReady = false; 

board.on("ready", function() { 
    isReady = true; 
}); 

wss.on('connection', function connection(websocket) { 
    websocket.on('message', function incoming(message) { 
     if(isReady) 
      board.servoWrite(5, message); 
    }); 
});