Google chrome - chrome.serial连接失败 [英] Google chrome - chrome.serial connection failed

问题描述

我尝试连接到手动工作的USB串口，如下所示：

I am trying to connect to USB serial which is working manually as below:

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

但是，当谷歌铬应用程序试图连接其失败。

But when Google chrome apps trying to connect its failing.

apps，background.js：

apps, 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);

推荐答案

在OSX上进行USB访问，发现Chrome无法获得访问USB设备，直到本地客户端应用程序（使用hidapi）运行并识别设备。

USB access on OSX, found that Chrome does not gain access to the USB device until the native client application (using hidapi) is running and recognize the device.

使用Windows操作系统，使用相同的代码，然后运行。

Use Windows OS with same code, then it works.

这篇关于Google chrome - chrome.serial连接失败的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！