Merge pull request #80 from tessel/kb-flash

adds USB storage module tutorial

_layouts/default.html

@@ -155,6 +155,10 @@ <h1><a href="https://tessel.io/"><nobr><img src=
               <a href="{{ site.baseurl }}/modules/servo.html" class=
               "side-bar-modules">servo</a>
             </li>
+            <li style="padding-left:10px;">
+              <a href="{{ site.baseurl }}/modules/storage.html" class=
+              "side-bar-modules">storage</a>
+            </li>
           </ul></a>
         </li>
         <li>

modules.md

@@ -63,6 +63,7 @@ If you've already tried out your modules, move on to [Tweet.](tweet.html)
 *   [Relay](modules/relay.html)
 *   [RFID](modules/rfid.html)
 *   [Servo](modules/servo.html)
+*   [Storage](modules/storage.html)
 
 <div class="greyBar"></div>
 </div>

modules/_module_footer.html

@@ -42,6 +42,10 @@ <h2>Choose another module</h2>
     <a href="servo.html"><span class=
     "moduleLink">Servo</span></a>
   </li>
+  <li>
+    <a href="storage.html"><span class=
+    "moduleLink">Storage</span></a>
+  </li>
 </ul>
 
 </div>

modules/storage.html

@@ -0,0 +1,10 @@
+---
+layout: default
+---
+
+{% capture include_install %}
+{% include_relative storage.md %}
+{% endcapture %}
+{{ include_install | markdownify }}
+
+{% include_relative _module_footer.html %}

modules/storage.md

@@ -0,0 +1,114 @@
+{::options parse_block_html="true" /}
+
+<div class="row">
+<div class="large-12 columns">
+
+## <img class="constrain-sm" src="https://s3.amazonaws.com/technicalmachine-assets/technical-io/modules/usb.png"> Storage (Flash Drive)
+
+[<i class="fa fa-github"> View source on Github</i>](https://github.com/nodejs/node/blob/master/lib/fs.js)
+
+### Step 1
+
+Make a directory inside your "tessel-code" folder called "storage", change directory into that folder, and initialize a tessel project:
+
+`mkdir storage; cd storage; t2 init`
+
+### Step 2
+</div>
+</div>
+
+<div class="row">
+<div class="large-6 columns">
+
+Plug Tessel into your computer via USB, then plug a USB mass storage device (flash drive) into either of Tessel's USB ports.
+
+</div>
+<div class="large-6 columns">
+
+![](http://i.imgur.com/uifn1p7.jpg)
+
+</div>
+</div>
+
+<div class="row">
+<div class="large-12 columns">
+
+### Step 3
+
+You don't need to install a library to use a USB storage module. We will use the [fs](https://nodejs.org/api/fs.html) (filesystem) library that's built into Node.js to interact with USB mass storage devices.
+
+In the folder where you ran `t2 init`, rename "index.js" to "storage.js" and replace the file's contents with the following:
+
+{% highlight js %}
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/publicdomain/zero/1.0/
+
+/*********************************************
+Write some text to a file on a USB mass storage
+device, then read it back.
+*********************************************/
+
+// Import the fs library
+var fs = require('fs');
+var path = require('path');
+var mountPoint = '/mnt/sda1'; // The first flash drive you plug in will be mounted here, the second will be at '/mnt/sdb1'
+var filepath = path.join(mountPoint, 'myFile.txt');
+
+var textToWrite = 'Hello Tessel!';
+
+// Write the text to a file on the flash drive
+fs.writeFile(filepath, textToWrite, function () {
+  console.log('Wrote', textToWrite, 'to', filepath, 'on USB mass storage device.');
+});
+
+// Read the text we wrote from the file
+fs.readFile(filepath, function (err, data) {
+  console.log('Read', data.toString(), 'from USB mass storage device.');
+});
+{% endhighlight %}
+
+Save the file.
+
+</div>
+</div>
+
+<div class="row">
+<div class="large-12 columns">
+
+### Step 4
+
+</div>
+</div>
+
+<div class="row">
+<div class="large-6 columns">
+
+In your command line, `t2 run storage.js`
+
+Now you can create, write to, read from, and otherwise manipulate files on USB storage devices!
+
+**Bonus:** Try writing some longer text (or output from a different module) by using streams. Hint: look up the fs function `createWriteStream`.
+
+To see what else you can do with a USB storage module, read the [fs](https://nodejs.org/api/fs.html) documentation.
+
+</div>
+<div class="large-6 columns">
+
+![](http://i.imgur.com/wKksk4X.gif)
+
+</div>
+</div>
+
+<div class="row">
+<div class="large-12 columns">
+
+### Step 5
+
+What else can you do with a USB mass storage device? Get inspired by a [community-created project.](http://tessel.io/projects)
+
+What are you making? [Share your invention!](//tessel.io/projects)
+
+If you run into any issues you can check out the [module forums](http://forums.tessel.io/c/modules).
+
+</div>
+</div>