python2.4 bin/instance fg

For some reason, the instance did not start.  Instead, I received the following Python error:

ImportError: No module named PIL

My first thought was to check Synaptic to make sure that the python-imaging package (which contains a copy of PIL, the Python Imaging Library) was installed properly.  It’s possible that I could have uninstalled it accidentally.  Suprisingly, according to Synaptic, the python-imaging package was installed.

Was my Python 2.4 installation somehow corrupted?  I tried reinstalling all of my Python packages.  Unfortunately, even after that, I still received that PIL ImportError.

Eventually, I decided to stop trying to get the official Ubuntu packages to work.  I usually rely on the Ubuntu repositories because installing software through other means may cause problems in the future if one tries to upgrade to the next distribution release (e.g. Ubuntu 9.10) using the in-place upgrader.

Instead, I decided to install the Python Imaging Library with the easy_install utility, as suggested in the “A note about PIL” section of Pinax documenation.  To do this, I ran the following command:

sudo easy_install -i http://dist.serverzen.com/pypi/simple PILwoTk

After installing PIL with the above method, my Plone 3 buildout worked.  It appears that the current Ubuntu PIL packages are broken for some reason.  If you need PIL and cannot get the Ubuntu PIL packages to work, this provides a simple workaround.

During late spring 2008, I used up about $600 of my personal savings to buy an ASUS EeePC 900.   In retrospect, the EeePC was probably one of the best purchases that I ever made.  It’s amazingly light (a little over 2 pounds) and gets decent battery life.  These two features were especially handy during my trip to the Plone Conference Sprints in Washington DC in October 2008.

In my typical geek/modder/hacker fashion, I proceeded to trick out the default Xandros operating system. I replaced the default tabbed interface and IceWM with the super-light XFCE desktop environment.  I even installed a rudimentary compositor so could have translucent windows.

At the time, I didn’t see the need to install a new OS.  Xandros *is* a derivative of Debian, after all.  What I didn’t realize is that ASUS made modifications to core libraries used in Debian, such as libaudio.  This made compiling certain applications rather difficult.  I also saw some weirdness with the Java classpath.   The only development environment that I was able to get running was the Plone toolkit: buildout, ZopeSkel, etc.  In other words, the default ASUS-modded Xandros operating system isn’t a very good operating system for software development.

Enter Ubuntu Eee Easy Peasy (it was renamed due to a trademark issue).  Essentially, it’s an unofficial fork of the Ubuntu distribution of Linux made specifically for netbooks.  When version 8.04.1 of Easy Peasy came out, I tried to install it, but couldn’t get my flash drive to successfully boot the LiveUSB copy of it.

Last night, I managed to get Easy Peasy to boot off of my flash drive.  When I decided to install it, I decided to manually partition the hard disk.  My EeePC 900 came with 2 hard disks.  The 4 gigabyte disk holds the system files and mounts to the “/” directory.  The 16 gigabyte disk holds user files and mounts to the “/home” directory.  Since the EeePC doesn’t have a swap partition (to prevent the flash memory used for the disks from being trashed), there’d probably be two partitions: one on the 4 gigabyte disk, one on the 16 gigabyte disk, both formatted with the Ext-3 filesystem. Right?

Wrong.

When I looked at gparted, the GNOME partitioner, I noticed that there were a total of 5 partitions.  Not shiny.  To inform readers (and future me) with what these partitions probably are used for, I’ve put together the following handy tables.  The information used to compile the “notes” and “label” columns of the first table was borrowed from the “What is on Partitions 3 and 4 ?” EeeUser thread.  The information for the “drive” and “filesystem” columns was found using the following command:

sudo fdisk -l

Finally, the information used to compile the “size” column was taken from gparted.

Drive: /dev/sda

Drive: /dev/sdb

As it turns out, this tends to happen (assuming the error appeared after installing a few Products into Zope/Plone) because either:

1. one of the installed Products is corrupted, or
2. one or more dependencies for the products is missing.

To fix this, we first have to uninstall all the add-on Products one-by-one until we isolate the one that is causing Zope/Plone to show that error message.  Keeping the error-causing plugin installed, we can then stop Zope, then restart it in foreground mode by typing the following commands (remember to replace /path/to/zope/instance with the real path to your Zope instance):

sudo /path/to/zope/instance/bin/zopectl stop
sudo /path/to/zope/instance/bin/zopectl fg

Note: the above commands are for Ubuntu/Debian/Debian-derivative Linux systems. They will require some modifications to work on other systems.

After Zope starts up by using the above commands, keep the terminal window open and browse to your Zope/Plone installation in a web browser.  When the page comes up (and the “No traversable adapter found” error is displayed), look at the terminal screen.  A traceback should have been displayed.  Near the bottom of the screen, there should be a specific error. The error at the bottom of the might screen start with:

ImportError:

If this is the case, you should search for the dependency that the error refers to in Google, download it, and install it.  For example, the product that I was trying to install required the DataGridField and AddRemoveWidget Products.  I was able to download those from <http://www.plone.org/products>.  After installing the dependencies, Zope/Plone worked perfectly.

However, if you receive a different error, there are a few main solutions that you could try:

1. Try re-downloading the Product after clearing your browser’s cache.  Internet Explorer is known to download files incorrectly and corrupt them, from time-to-time.
2. Try downloading a different version of the Product.  There is a slight chance that the particular version of the Product that you were trying to install had a bug.  If this is the case, make sure to report the bug so that it can be fixed by the author.
3. Check to see if the Product that you are using is compatible with the version of Plone that you are using.  Many plugins that are designed for Plone 2 will not work on Plone 3 without some modification.  There may, however, be a pre-release version of the Product that does work for your version of Plone.

Hopefully, these tips will help you!  If you have any thoughts on this subject, feel free to comment below!

I met and socialized with a students and mentors from all over the world—including from Thailand, Russia, South Africa, the UK, Germany, Poland, Switzerland, Belgium and the USA—to celebrate the conclusion of the first-ever Google Highly Open Participation Contest.  In addition to all of this social interaction, I had the chance to ride roller coasters at Great America, tour the Googleplex, talk to other GHOP students and mentors, eat at two of Google’s famous cafés, and listen to a set of amazing presentations by various tech luminaries who work for Google.

Today, I decided to put together a recap entry about the activities of the two days and what we did during them:

Thursday

I started the day by driving down to the hotel with my mom where the other GHOP students were staying for the four days of their trip.  We picked up our Google/GHOP swag kits, which each included various items such as:  a hat, a backpack, a sweatshirt, a t-shirt, etc.  Afterwards, we proceeded to talk to other students about the projects that we worked on.

A few minutes later, our group’s bus arrived and then we drove off to the secret location of where breakfast was supposed to be.  As the bus stopped, people began to chuckle.  We were going to have our celebratory GHOP breakfast at an IHOP restaurant!

Many fun discussions, a set of pancakes cut into the shapes of specific letters and arranged so they said GHOP, and several group photos later, we all boarded our bus and headed off to our next destination: Great America.  We spent the rest of the day (until 7pm) riding roller coasters, water rides, and other various attractions.  At 7pm, we boarded our bus and went back to the hotel.  While many decided to go to the Bay Area Python Interest Group’s meeting, I instead decided to go home (I was much too tired).

Friday

On Friday, we all started the day by meeting in the lobby of the hotel.  After thirty minutes of fun, interesting discussions, our bus stopped in front of the hotel.  We all hopped on board and began the short journey off to the Googleplex.

When bright, multi-colored umbrellas appeared next to the bus, we all knew that we were there.  We all jumped off the bus, signed in, and headed off to Café Moma for breakfast.  We spent breakfast discussing our various open-source projects.  Roughly an hour later, we went on a tour of the Googleplex.

Around 11 AM, we began our awards ceremony. Chris DiBona, Alan Eustace, and Leslie Hawthorn led the awards ceremony, gave speeches, and handed out the awards to students. Mentors, students, and parents posed for photos.

Afterwards, we all walked over to Charlie’s Café and had lunch.  I had the opportunity to have lunch with Alexander Limi, co-founder of the Plone project. During lunch, various student/mentor pairs were taken to a rather shiny Google video studio and interviewed for use on YouTube.  Alexander Limi and I were interviewed in one of these videos. As of this post, these videos have not been put up yet. When I get a link to it/them, I’ll make sure to embed it/blog about it. The videos have been put up on YouTube:

A video about the GHOP Awards Ceremony that also features parts of the interviews with the contestants.

After another group photo session in front of Google signs, we went back to the room where the awards ceremony occurred and finished the day by listening to a set of talks given by tech-industry stars such as Guido van Rossum, Romain Guy, Jeff Dean, Bharat Mediratta, and Mike Bland.  Halfway though the talks, we took a short break to devour a beautifully-made cake with the GHOP logo on it.

Photos

Below, I’ve included a few of the photos that my mom took (click on photos to enlarge them).  You can find more photos of the event in the ghop07 tag on Flickr and in the ghop07 tag on Picasa Web Albums.

Specifications

Details

This robot was designed to be the most intelligent robot that I’ve ever built.  It has numerous sensors, including a Sharp GP2D12 IR ranger and Parallax QTI line sensors.  This IR distance detector is mounted on top of a servo-controlled turret so that the sensor can detect opponents that are off to the side of the robot.  The turret is designed such that the GP2D12 is pointed slightly downwards so that smaller robots can be detected.

The frame of the robot is designed to be extremely strong.  It is made out of polycarbonate plates that are connected together with custom-made brass angle pieces.  A high light absorption, low light refelection ABS plate is mounted to the front to make the robot harder to detect by IR sensors on opponent robots.

Photos

Sun SPOTs are programmed in Java. You can use high-level code to control them; you don’t have to control registers and manually implement communications protocols such as I2C and SPI. Instead of writing complex code to control devices such as servos, you can use pre-created classes and interfaces instead. This makes the programming learning curve extremely easy.

Programming the Sun SPOTs was my first experience with the Java language. Since I have used other languages such as C#, Visual Basic, and JavaScript (which, contrary to popular belief, is not a subset of Java), learning Java was quick and easy. I was over the learning curve in ten or fifteen minutes.

Netbeans, the reccommended IDE for use with the Sun SPOTs, also made learning Java much easier. Whenever the IDE detected a syntax error, it put an exclamation point icon in the margin. I was able to click on the exclamation point and find out what the exact problem was. All of the error messages were very clearly written and easy to understand; there were no strange error messages. For certain errors, Netbeans put an exclamation point and a lightbulb rather than just an exclamation point. When I clicked this, a menu appeared that gave me possible solutions to the problem. When I clicked the solution, the changes were automatically inserted into my code files.

From here, all I had to do was write some driver code for some of the specialty sensors that I was using on the robot and integrate these into a Sun SPOT application. I was able to get my first application together in around thirty minutes (including the time that it took me to learn how to program in Java). I’m very impressed with how flat the learning curve for the platform is.

DISCLOSURE OF MATERIAL CONNECTION: http://cmp.ly/2

I’ve recently had the chance to use Sun Microsystem’s SPOT development kit.  I’ve tested their software on Windows XP and it installs rather nicely, just as long as you follow the instructions and use the CD included in the box.

Today, I decided to install the software on a computer running a vanilla install of Ubuntu 8.04.  You can use the CD included in the box to do this (if you follow the “tweak some important settings” section), but I wanted to use the Ubuntu repository packages whenever possible.  Here are my findings on how to do this; it turns out to be pretty easy.

Install the Java Development Kit

First, we get to install the Java Development Kit (JDK) by installing the following packages using the Synaptic Package Manager:

• sun-java6-jdk
• sun-java6-demos (optional)

Make sure to click “OK” when it asks you to install any dependencies.

Install NetBeans

Now, we get to install the following package using Synaptic (this will also install Ant when it installs dependencies, so we don’t have to install it separately):

• netbeans

Make sure to click “OK” when it asks you to install any dependencies.

Install Some NetBeans Plugins

First, go and download the Sun SPOT NetBeans Plugins. You can then open up NetBeans and then go to Tools » Plugins.  Click on the “Downloaded Plugins” tab and the “Add Plugins…” button.  Select the file that you just downloaded and click “OK.”  Click the “Install” button and click through the licensing and warning windows.  You can now go into the “Available Plugins” tab and install the rest of the Sun SPOT related plugins, clicking “OK” on the license and wrning windows that pop up.

Run the Sun SPOTManager

Now, we just have to run the SPOTManager application.  It happens to be a Java WebStart application, so to install it we just have to go to <http://www.sunspotworld.com/spotmanager/> and click on the icon next to “Launch Sun SPOT Manager application”.  You will be required to have the program check your configuration; everything should pass without any trouble.

Once SPOTManager loads, you should install a SPOT SDK.  To do this, click on the “SDK” tab of the application.  Then, click on “v3.0 Purple (Latest Update)” under “Available SDKs” and click the “Install” button.  You can then accept the license agreement and install the SDK.

Tweak Some Important Settings

Out of the box, NetBeans has some issues communicating with the SPOTs, to fix this, we have to change the default port that NetBeans tries to use when communicating with them.  We do this by going into the folder that the SDK was installed into and opening up the default.properties file in a text editor.  You need to add the following line to the file:

port=/dev/ttyACM0

Now, you can save and close the default.properties file.  To make SPOTManager work, there is an in-depth thread on the SunSPOTWorld forums on how to tweak it.  Look for bbraem’s script on the second page of the thread.  You can replace the spotfinder script (located in the bin directory of the SDK that you installed) with bbraem’s script.  You’ll need to name the new script “spotfinder” as well, so you’ll probably want to make a backup of the original script in case anything goes wrong.

From Here

Finally, you can plug in your SPOTs and start using them!

DISCLOSURE OF MATERIAL CONNECTION: http://cmp.ly/2

During the long day, I managed take at least five decent photos (I was too busy talking to people), which are showcased below.  As usual, you can click on any of the thumbnails to make them larger.

You can click on any of the photos to see them at a higher resolution.