Google Chrome Extension serial port on website

Question

I use chrome.serial to communicate with device on COM port and i need provide basic api for javascript on my web-site. First try was with content_script + messaging, but i c

Answer 1

index.html

Connect

main.js

var connectionId;

/* Converts a string to UTF-8 encoding in a Uint8Array; returns the array */

var str2ab = function(str) {
   var encodedString = unescape(encodeURIComponent(str));
   var bytes = new Uint8Array(encodedString.length);
   for (var i = 0; i < encodedString.length; ++i) {
      bytes[i] = encodedString.charCodeAt(i);
   }
   return bytes.buffer;
};

var options = {
  'bitrate': 115200,
  'dataBits': 'eight',
  'parityBit': 'no',
  'stopBits': 'one'
}

document.addEventListener('DOMContentLoaded', function () {
  document.querySelector('button').addEventListener('click', btnSend);
  chrome.serial.connect('COM3', options, function(info) {
    connectionId = info.connectionId;
    console.log("Connection established.");
  });
});

var btnSend = function() {
  var msg = "hello printer 123456\n";
  chrome.serial.send(connectionId, str2ab(msg), function() {} );
}

manifest.json

{
  "name": "Printer at COM3 test",
  "version": "1",
  "manifest_version": 2,
  "permissions": ["serial"],
  "minimum_chrome_version": "23",
  "icons": {
    "16": "icon_16.png",
    "128": "icon_128.png"
  },
  "app": {
    "background": {
      "scripts": ["launch.js"]
    }
  }
}

launch.js

chrome.app.runtime.onLaunched.addListener(function() {
  chrome.app.window.create('index.html', {
    id: "mainwin",
    innerBounds: {
      width: 320,
      height: 240
    }
  });
});