Sample of serial device API for Chrome applications.

ChromeSerial.js

// class
function Serial(path, birate, dataBit, stopBit, parityBit, stageManager) {
	this.path = path;
	this.birate = birate;
	this.dataBit = dataBit;
	this.stopBit = stopBit;
	this.parityBit = parityBit;
	this.stageManager = stageManager;
	this.connectionId = null;
	this.buffer = "";
}

// create a connection
Serial.prototype.connect = function() {
	chrome.serial.connect(
		this.path,
		{
			persistent: false,
			bitrate: this.birate,
			dataBits: this.dataBit,
			parityBit: this.parityBit,
			stopBits: this.stopBit
		}, 
		(function(info) {
			this.connectionId = info.connectionId;
			chrome.serial.onReceive.addListener(this.onReceive.bind(this));
		}).bind(this)
	);
}

// disconnect all connections
Serial.prototype.reset = function() {
	chrome.serial.getConnections((function(cons){
		cons.forEach(function(item, index, array) {
			chrome.serial.disconnect(item.connectionId, function(result) {
				console.log(result);
			});
		});
	}).bind(this));
}

// receiver function
Serial.prototype.onReceive = function(info) {
	if (info.data) {
		var c = ab2str(info.data);
		
		if (c === '\n' || c === '\r\n') {
			if (this.buffer != "") {
				this.stageManager.updateWeight(parseFloat(this.buffer.split(",")[2]));
				this.buffer = "";
			}
		} else if (c != '\n') {
			this.buffer += c;
		}
	}
}

function ab2str(buf) {
  return String.fromCharCode.apply(null, new Uint8Array(buf));
}