WebJack-Firmata

...is a wrapper for WebJack to use as transport layer for firmata.js. WebJackPort is inspired by EtherPort from Rick Waldron.

Try it out in this live demo: https://publiclab.github.io/webjack-firmata/example/

Note: WebJack is not stable yet, and WebJack-Firmata is neither. You may have to reload the demo site several times until you get an output in the 'Log' section.

Keyboard bindings

A second example, showing triggering of Arduino pins via keyboard keypresses, is available at https://publiclab.github.io/webjack-firmata/example/keyboard/

Install

npm install --save webjackport

Use

var Firmata = require("firmata").Board;
var WebJackPort = require("webjackport");
var board = new Firmata(new WebJackPort());

board.on("ready", function() {
  console.log("READY!");
  console.log(
    board.firmware.name + "-" +
    board.firmware.version.major + "." +
    board.firmware.version.minor
  );

  var state = 1;

  this.pinMode(13, this.MODES.OUTPUT);

  setInterval(function() {
    this.digitalWrite(13, (state ^= 1));
  }.bind(this), 500);
});

Also take a look at the demo site in the example folder.

Sketches

Three example sketches are provided:

• SimpleDigitalFirmata
• ConfigurableFirmata
• StandardFirmataWebJack

SimpleDigitalFirmata and ConfigurableFirmata are capable of setting and reading digital pins. The first one is implemented with the standard Firmata library, the latter with ConfigureableFirmata.

StandardFirmataWebJack is a modification of the standard Firmata firmware and thus has all its capabilities. Additionally a custom SysEx command is implemented, that reports exactly one analog reading.

All sketches are configured with a 10 millisecond delay in the processing loop. This is due to crosstalk from requests messages. An immediate reply will make it difficult for WebJack to distinguish the crosstalk from the actual reply.

Known Issues

Currently, it is required to create the board with additional options:

var opts = {
  reportVersionTimeout: 2500,  // increase if no sound is played after loading the site
  skipCapabilities: true  // we skip this for now, reception via WebJack is not reliable enough
};
var board = new Board(new WebJackPort(), opts);

Audio cables may introduce crosstalk that can lead to reception of sent data. As a result of that, firmata can have difficulties to decode answers correctly. It can help to assign empty handler functions to SysEx requests as workaround:

board.sysexResponse(CAPABILITY_QUERY, function (data){});

##Developers

Help improve Public Lab software!

• Join the '[email protected]' discussion list to get involved
• Find lots of info on contributing at http://publiclab.org/wiki/developers
• Review specific contributor guidelines at http://publiclab.org/wiki/contributing-to-public-lab-software

Building

webjackport.js is built using a Grunt task from the source files in /src/, and the compiled file is saved to /dist/webjackport.js. To build, run grunt build. To watch files for changes, and build whenever they occur, run grunt.

Building the demo

The demos in /example/ are bundled with Webpack. Before executing webpack, do npm install -- and cd example -- since you have to run webpack from inside the example directory. The code in /example/bundle.js, is then compiled from /example/Demo.js.