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 But when Google chrome apps trying to connect its failing.
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);