在nodejs中传递javascript消息

Question

谁能帮我解决这个问题吗？我想每次收到消息时都将消息从websocket传递到串口

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

您应该在 board 准备就绪后添加监听器。

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

要么声明一个变量来告诉您它是否准备好。

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);
    });
});