2012 will also see me starting a new job at the University of Leicester, which I am really excited about. I’ll be working as a Web Developer in the Marketing and Communications team and can’t wait to get stuck in. Developing for the web has been a big part of my working and personal life for the past decade or so, but this is the first job I’ve had where it will be the main focus of the role. Given the phenomenal rate of change in the industry I can’t wait to devote my full working day to learning about and applying some of the fascinating technologies that are being developed.

I’ve also been tricked agreed to run a 10k “fun run” in March with some of my former colleagues. We’ll be raising money for Rainbows Hospice for Children and Young People so give generously. Because of this 2012 (or the first three months at least) will involve me doing a bit of training. I haven’t done anything approaching exercise since May, so I’ve got a fair bit of ground to make up there.

Lastly, but most significantly, I’m going to become an uncle in the summer to my brothers child. I can’t say how excited my wife and I are and we can’t wait to meet the little Russell.

So that’s what I’m looking forward to in 2012. It’s gonna be fun.

There is however, still a way of getting this functionality on the Kindle 4 NT, but it is quite fiddly and requires you to have some knowledge of Linux file systems, basic networking and SSH. I achieved this using a Linux (Ubuntu) PC, there instructions are probably largely similar for MACs too. Windows users will have to install some extra software tools and the networking bit will be different too (Don’t ask – I won’t know).

Basically all we’re going to do is move the screensaver images folder to the part of the kindle that is accessible over USB and creating a symbolic link to this location. However, the route from here to there is a bit contrived. If you’re not sure what you’re doing it’s best to ask a techo-literate friend to help out. Oh, it should also go without saying that this probably invalidates your warranty too.

Diagnostic Mode

The first thing we need to do is put the Kindle in to Diagnostic Mode.

1. Connect the Kindle to your PC with the USB cable.
2. Create a file on the Kindle called ENABLE_DIAGS
3. Unmount the Kindle and disconnect the USB cable.
4. Restart the Kindle
   
   [MENU] Settings [MENU] Restart
   
   This will take a few minutes.
5. You should now be in Diagnostic Mode.

Gaining Root Access

Next we need to connect to the Kindle as root which will allow us to fiddle around with it.

1. Connect the Kindle to your PC with the USB cable. It should NOT mount.
2. Enable USB Networking from the menu.
   
   Misc individual diagnostics > Utilities > Enable USBNet
3. The Kindle should now be a network device on your PC.
   
   ifconfig
4. Configure a IP address for the device.
   
   ip addr add 192.168.15.241/24 dev usb0
5. You should now be able to SSH in to the Kindle as root.
   
   ssh root@192.168.15.244
   
   The password is “mario”.
   
   Edit: If “mario” doesn’t work try this tool.
6. You now have root access to your Kindle

Moving the Screen Savers

Now we’re going to move the screensavers from their existing location to a new folder in /mnt/us/, which is the folder accessible via USB.

1. First mount the required partition.
   
   mount /dev/mmcblk0p1 /mnt/base-mmc
2. Backup the existing screensavers.
   
   mv /mnt/base-mmc/opt/amazon/screen_saver/600x800 /mnt/base-mmc/opt/amazon/screen_saver/600x800.bak
3. Create a folder for custom screen savers.
   
   mkdir /mnt/us/screensaver
4. Create a link from the screen saver location to the new folder.
   
   ln -sfn /mnt/us/screensaver /mnt/base-mmc/opt/amazon/screen_saver/600x800
5. You can optionally copy the existing screen savers to the new folder if you want to keep them.
   
   cp /mnt/base-mmc/opt/amazon/screen_saver/600x800.bak/* /mnt/us/screensaver/
6. End the SSH session.
   
   exit
7. Exit Diagnostic Mode
   
   Exit, Reboot or Disable Diags > Disable Diagnostics > To continue – FW LEFT
8. Wait a few minutes for the Kindle to reboot.
9. That’s the screen savers moved!

Setting Custom Screen Savers

Now you can copy your own screen saver images to your Kindle. All you need to do is connect your Kindle to your PC with the USB cable and copy the images you want in to the screensaver folder.

The images files must be 600×800 pixels. I think they also have to be PNG files and 72dpi in 32bit indexed greyscale. Some people on the forums have said that this isn’t necessary, others say it is. But this format works fine for me where others didn’t.

There are various sites out there with Kindle screen savers to download, you may or may not need to do some image conversion. I leave it to you to experiment.

You also have to researt the Kindle fully ([MENU] Settings [MENU] Restart) before the new screen savers will work.

Have fun!

Edit: Here’s the original Kindle 4 Screen Savers.

Pretty much the first thing I did with it is start hunting for free web development ebooks. I was quite surprised to find that there wasn’t a free tag reference for HTML5.

So I made one.

It’s not in the Amazon store, but you can download and copy it to you Kindle over USB.

Download HTML5 Reference here.

I’ve tweaked this code to build a simulation of objects orbiting about a point. The only key difference is that the gravity for each ball is recalculated relative to the “sun” with each animation step. I’ve also removed collision detection with the window borders.

There’s a live example here. View the source for the.. er.. source.

Create a file called BRANCH-README in the repo root, and for each new branch include a summary describing what the the branch is for.

Branch: bugfix-123-autherror
Author: Craig Russell
Date: Fri 18th Nov 2011
Description: Fix for bug #123 - User receives authentication error when uploading content.

What do you think? Do you have a branch management strategy you’d like to share? Drop a comment below.

First up, use rails to generate a new plugin.

$ rails generate plugin HelloWorld

This will create a folder in /vendor/plugins/hello_world containing template files for the plugin. What it won’t do is create a test file for RSpec, so we’ll create it manually later. This is a known issue.

In the plugin folder there’s a few files, most of which are self-explanatory. We’re only going to be interested in hello_world/init.rb and hello_world/lib/hello_world.rb.

hello_world/init.rb tells Rails what to do with the plugin. We’re not going to do too much, so we just need to require the main class file.

# Include hook code here
require 'hello_world'

Next we create the main class in hello_world/lib/hello_world.rb.

# HelloWorld
class HelloWorld
end

Before we go any further we should set up a test, because we do things properly. RSpec tests live in /spec so we’ll create a folder for plugin tests and create a spec file for our plugin there.

$ mkdir /spec/plugins
$ touch /spec/plugins/hello_world_spec.rb

Lets define a simple test for our plugin in /spec/plugins/hello_world_spec.rb

require 'spec_helper'
describe HelloWorld do
  describe "should have method" do
    it "'hi'" do
      response = HelloWorld.instance_methods.include? :hi
      response.should == true
    end
  end
end

We’ve done a few things here, firstly we’ve required the RSpec helper file, all RSpec tests need this. The first describe block is defined with the name of the class we are testing. Then we’ve added a test to check that a method exists. If you run the test, it should fail.

$ rspec /spec/plugins/hello_world_spec.rb

Now we can add a method to the HelloWorld class, which should get the test to pass.

# HelloWorld
class HelloWorld
  def hi
    "Hello World!"
  end
end

That’s it!

Now you have a working plugin, you can use it in your Rails application. You can create objects in controllers and call functions from views, there’s no need to explicitly require the plugin anywhere.

# app/controllers/pages_controller.rb
class PagesController < ApplicationController
  def hello
    @hw = HelloWorld.new
  end
end

<!-- app/views/pages/hello.html.erb -->
<p><%= @hw.hi %></p>

Installing Everything

I’ve tried and failed to install Ruby and Rails before, on one occasion I completely frigged my LAMP stack. I run Ubuntu on my laptop and this is the guide that worked for me.

How to install Ruby on Rails in Ubuntu 11.10

Having installed everything, you might notice that the Ruby version swaps back to 1.8.7 with every new session. You can set the default version of Ruby by running this command.

$ rvm --default use 1.9.2

Starting With Ruby

Before starting with Rails, it’s well worth having a good grasp of Ruby. I found these two tutorials very helpful. The first is ideal if (like me) you’ve never written a line of ruby. The second is a tour-de-force around the language.

Ruby in 20 Minutes

Ruby Koans

When working through the Koans, have an interactive ruby console open to try out things as you learn them. You can open a Ruby console like this:

$ irb

Starting With Ruby on Rails

Once you’re up-to-speed with Ruby, you can start dipping your toe in to Rails. I’ve not spent much time with Rails yet, but so-far, I’ve found these resources very useful.

Getting Started With Rails

This is a short exercise that takes you through the basics of Rails while building a simple blog platform.

Rails Tutorial

You should definitely take the time to work your way through the Rails Tutorial. The course covers all areas of the framework (including versioning with Git, unit testing with RSpec and deploying to Heroku) on the way to building a Twitteresq micro-blogging app. The author suggests that no prior knowledge of ruby is needed, but personally I found it better to work through the Ruby Koans first to better separate the Ruby from the Rails in my mind.

Resources

Rails API

A complete reference for the Rails API and the Ruby language.

PHP to Ruby

If you’re coming to Ruby from PHP (as I am) this site is your bi-lingual dictionary.

As part of the course we used one of the major data mining products on the market. As an class of Masters Degree students, learning about the subtle intricacies of our chosen subject, the product served us well. We were able to tweak and twiddle with more switches than a 747. We had the luxury of time to run, re-run, rinse and repeat data processing over and over. I’m equally sure that for professional data mining consultants, hired by large wealthy companies to trawl vast private data repositories, these products are worth the thousands of pounds of license fees they pay.

But what about everyone else? What about the campaigns working to holding government to account over public data? What about the new-breed of data journalist exposing stories otherwise hidden in obscure facts and figures? What about the data evangelists enlightening and entertaining with wonderful visualisations? How accessible is data mining for these people? How affordable? How usable?

Not enough.

With increasingly more data being placed in the public domain, so increases the need for tools to explore this data. Data Mining tools are out there, but are no-where-near as accessible as the data that requires them.

It is with this in mind that I have begun to develop an accessible, usable and intuitive suite of tools to explore data sets. The first of these, Clusterbomb, will mine data sets to expose the hidden clusters of records buried within. I’m expecting to have an alpha release out early next year, but for now sign up to the mailing list to keep an eye on developments. Clusterbomb is also on Twitter and Facebook.

❝To be ahead of the rest, you need to see more than they do❞

Repeating Commands

Repeat last command

!!

Repeat last command that started with x

!x

Repeat last command that has the substring x

!?x

Repeat 10th command in the history file

!10

Repeat 10th from last command in the history file

!-10

Fetching Parameters

Fetch parameters from last command

!!*

Fetch first parameter from last command

!!^

Fetch last parameter from last command

!!$

Fetch third parameter from last command

!!3

Modifiers

Repeat last command substituting foo for bar

!!:s/foo/bar/

Print last command without running it

!!:p