Google chrome - connexion chrome.serial échoué

Question

Je suis en train de se connecter à série USB qui fonctionne manuellement comme ci-dessous:

$ ls /dev/cu.* 
/dev/cu.Bluetooth-Incoming-Port /dev/cu.usbserial 
$ screen /dev/cu.usbserial 9600 

Mais quand les applications Google Chrome essayant de connecter son échec.

applications, background.js:

var DEVICE_PATH = '/dev/cu.usbserial'; 
var serial = chrome.serial; 

function log(msg) { 
    console.log(msg); 
} 

var ab2str = function(buf) { 
    var bufView = new Uint8Array(buf); 
    var encodedString = String.fromCharCode.apply(null, bufView); 
    return decodeURIComponent(escape(encodedString)); 
}; 

var str2ab = function(str) { 
    var encodedString = unescape((str)); 
    var bytes = new Uint8Array(1); 
    bytes[0] = parseInt(encodedString); 
    return bytes.buffer; 
}; 

// Object 
var SerialConnection = function() { 
    this.connectionId = -1; 
    this.lineBuffer = ""; 
    this.receiveTimeout =50; 
    this.boundOnReceive = this.onReceive.bind(this); 
    this.boundOnReceiveError = this.onReceiveError.bind(this); 
    this.onConnect = new chrome.Event(); 
    this.onReadLine = new chrome.Event(); 
    this.onError = new chrome.Event(); 
}; 

SerialConnection.prototype.onConnectComplete = function(connectionInfo) { 
    if (!connectionInfo) { 
    log("Connection failed."); 
    return; 
    } 
    this.connectionId = connectionInfo.connectionId; 
    chrome.serial.onReceive.addListener(this.boundOnReceive); 
    chrome.serial.onReceiveError.addListener(this.boundOnReceiveError); 
    this.onConnect.dispatch(); 
}; 

SerialConnection.prototype.onReceive = function(receiveInfo) { 
    if (receiveInfo.connectionId !== this.connectionId) { 
    return; 
    } 

    this.lineBuffer += ab2str(receiveInfo.data); 

    var index; 
    while ((index = this.lineBuffer.indexOf('$')) >= 0) { 
    var line = this.lineBuffer.substr(0, index + 1); 
    this.onReadLine.dispatch(line); 
    this.lineBuffer = this.lineBuffer.substr(index + 1); 
    } 
}; 

SerialConnection.prototype.onReceiveError = function(errorInfo) { 
    log('Error'); 
    if (errorInfo.connectionId === this.connectionId) { 
    log('Error'); 
    this.onError.dispatch(errorInfo.error); 
    log('Error'); 
    } 
    log('Error'); 
}; 

SerialConnection.prototype.connect = function(path) { 
    serial.connect(path, {bitrate: 9600}, this.onConnectComplete.bind(this)); 
}; 

SerialConnection.prototype.send = function(msg) { 
    if (this.connectionId < 0) { 
    throw 'Invalid connection'; 
    } 
    serial.send(this.connectionId, str2ab(msg), function() {}); 
}; 

SerialConnection.prototype.disconnect = function() { 
    if (this.connectionId < 0) { 
    throw 'Invalid connection'; 
    } 
    serial.disconnect(this.connectionId, function() {}); 
}; 

// -- Connect 
var connection = new SerialConnection(); 
connection.onConnect.addListener(function() { 
    log('connected to: ' + DEVICE_PATH); 
}); 

connection.onReadLine.addListener(function(line) { 
    log('read line: ' + line); 
}); 

connection.onError.addListener(function() { 
    log('Error: '); 
}); 
connection.connect(DEVICE_PATH); 

Answer 1

accès USB sur Mac OS X, a constaté que Chrome ne gagne pas l'accès au périphérique USB jusqu'à ce que l'application client natif (à l'aide de hidapi) est en cours d'exécution et Reconnaître l'appareil.

Utilisez Windows OS avec le même code, puis cela fonctionne.