Raspberry Pi Configuration Settings with raspi-config

Initial raspi-config screen with setup options.
Initial raspi-config screen with configuration options.

While working on our latest project with the Raspberry Pi, I was installing various modules on the Raspbian version of Linux, when I was informed that I had run out of disk space. I was confused, because the SD card I was using had 4 GB, and I was sure that the modules I had installed were not that large.  It turned out that when you initially flash the SD card, it sets up the root partition as though you have 2 GB free on the SD card.  To fully utilize the available space on the SD card, you need to repartition the root drive.  Fortunately, that turns out to be very easy with a built-in utility called “raspi-config”.  Just type in “raspi-config” at the prompt, and you see the screen pictured at right.  Choosing the second option “expand_rootfs” automatically configures the root partition to utilize all available space on the SD card.  As I mentioned in a previous post, this utility is also useful for changing the default keyboard setup and timezone if you don’t happen to be from England.  I had to do a bit of googling to figure this out, so I hope this post saves someone a little bit of effort.

Adventures with Raspberry Pi – Setting Up

Raspberry PiThe Rasbperry Pi is a fully functional cleverly designed microcomputer that you can buy for only $35 (a more stripped-down version will soon be available for $25).  The developer’s intent was to design an inexpensive computer to be used by kids in developing countries to learn programming.  There has been a great demand by hobbyists, however, who have used it in a variety of projects.  I won’t list them all here, but I recommend Googling “Raspberry Pi project ideas” for inspiration.  There is a large online community devoted to all things Raspberry Pi related.

As soon as we heard about the Raspberry Pi, my middle son and I were excited to check it out, so we went online and ordered two of them.  There are only two online retailers who sell the Raspberry Pi for $35 in the U.S. – Allied Electronics and Element14.  If you purchase anywhere else, including Amazon, you’re probably paying a marked-up price from a reseller.

While waiting for our Pis to arrive, I downloaded the Raspberry Pi User Guide from the Amazon Kindle Store (it is also available in paperback) to read up on it.  I highly recommend this guide as it gives detailed instructions on setting up your Pi for initial use, and provides links to many online resources.

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A LEGO Mindstorms NXT Curriculum

LEGO Mindstorms SetLast spring I taught an after-school class on LEGO Mindstorms robotics and the NXT programming language at my son’s elementary school.  The motivation for the class was to provide a good introduction to LEGO Mindstorms, and I hoped that some of the kids who took the class would sign up for our FLL (FIRST LEGO League) team in the fall.

I worked pretty hard to create a curriculum for the class, and I’m uploading it in case anyone would like use the lessons to teach a similar class.  LEGO Mindstorms is a terrific, easily accessible, introduction to robotics, and frankly just a whole lot of fun.  One word of advice:  If you don’t own a set yet, you might want to wait until the fall, as a new revision, called Mindstorms EV3 will be coming out then.

You can download the curriculum here in Word Document format (large file): 

or download it in PDF format:


LED Matrix Shirt

LED Matrix Shirt
Shirt with a detachable LED Matrix panel. You can see the letter “P” and the beginning of the letter “O” for “PONG”.

After completing the Programmable LED Sweatshirt project with the Arduino LilyPad.  I was intrigued by the idea of a soft-circuit LED array that could be used as a scrolling message board and general purpose display.  With Halloween coming up, my son and I decided to make our own costumes.   We came up with the idea of a T-shirt containing an LED array that could scroll messages and display simple graphics.

Once we got the basic LED array working, we decided to add a small joystick to make our project interactive.

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6x6x6 LED Array

I just finished my latest project, but I’m still in the process of writing up the backlog of older projects we’ve done.   I’m too happy with this project and too impatient not to share it right away, so I promise a write-up later.  In the meantime, please enjoy this video of my 6x6x6 LED Cube, powered by an Arduino Uno.

Programmable LED Sweatshirt

Programmable LED Sweatshirt
Programmable LED Sweatshirt (the ‘dots’ are the lit-up LEDs)

I discovered e-textiles this past fall.  The Arduino LilyPad  is a micro controller designed to be included in clothing and other projects using soft circuits.  There are some interesting LilyPad projects online, such as Leah Buchleys turn signal jacket,  this jacket with an LED array, and this LED Matrix quilt by Katie Dektar.  Reading about these projects inspired me to try one myself.  I know the basics of sewing, so I figured that part wouldn’t be too bad, and I was interesting in learning more about micro controllers like the LilyPad.

Since my FIRST LEGO Leauge (FLL) team (I hope to write about FLL in a different post) had an upcoming tournament, I decided to make a light-up sweatshirt with our team’s logo.  I didn’t document the construction process at the time, so there are no photographs of the work in progress, however the project is simple enough that you can easily see how it works by viewing the final result.

The step-by-step process and results of this project are below:

Read moreProgrammable LED Sweatshirt

Jr. FLL Expo at Legoland

Today was a big day for the members of our two Jr. FLL teams, the Super Sonic Seniors and the Ultimate Elderlies.  The coaches and kids, along with family and friends, hopped into cars, and drove from Los Angeles to Carlsbad, CA for the largest Jr. FLL Expo in the world.  Over 100 Jr. FLL teams will attend one of four Expo sessions this weekend in which they share their research projects and posters with other teams and judges from the Legoland staff.

The Super Sonic Seniors posing, sort of, in front of their poster and LEGO model at the Jr. FLL Expo.
The Super Sonic Seniors posing, sort of, in front of their poster and LEGO model at the Jr. FLL Expo.

As I mentioned in a previous post, this year’s Jr. FLL research theme is “Super Seniors”, involving an interview with a senior citizen, and research into some change that the senior noticed in her lifetime.  The Super Sonic Seniors put together a poster detailing the history and development of television and built a model of a television containing a rotating stage with two scenes.  Placing the TV “remote” in front of a distance sensor in the model triggers the rotation of the stage, which changes the content and “channel” being shown on the television.  The Ultimate Elderlies researched the evolution of long distance communication, doing detailed research on the Pony Express, the telegraph, cell phones and emails as successive improvements in mankind’s ability to communicate.  Their LEGO model contained Lego renditions of each of these modes of communication, including a motor-driven telegraph that made a very realistic clicking sound, and a scene of a LEGO driver using his cell phone in a car, only to be pulled over by a policeman.

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Jr. FLL – Super Seniors rock!

Jr. FLL (Junior FIRST LEGO League) is a terrific organization designed to introduce kids ages 6 to 9 to the concepts of basic engineering, scientific research and teamwork, among other valuable skills. This is my second year in a row coaching my youngest child’s Jr. FLL team, (actually, a friend and I are co-coaching two teams together) and we’re working hard, learning a lot, and truly enjoying the process.

Our Team T-shirt Designs
Our Jr. FLL Team T-shirts. It’s important to have cool shirts to wear to the Expo. Drawings were done by team members

Each year, the Jr. FLL organization promotes a different scientific theme. This year’s is “Super Seniors”. Our two teams, each consisting of six third graders,  named themselves “Super Sonic Seniors” and “Ultimate Elderlies”.  This year’s Jr. FLL project requires each team to find and interview a “senior partner” over the age of 60 about changes the senior has experienced in his lifetime. The team then chooses one of the topics they discussed, researches it, and prepares a poster board on what they have learned and builds a motorized LEGO model related to their research topic.

The “Super Sonic Seniors” chose to research changes in television. We learned a lot about television technology and content in the years since its inception.  Did you know that the first working television system was mechanical and developed in the late 1800’s?  In addition to their research,  the team members created a LEGO model of a television that “changes channels” by rotating a platform with two different scenes when you press a button on the “remote”.

Read moreJr. FLL – Super Seniors rock!

Hello world!

This is my first blog post, and I think the default title “Hello world!” is very appropriate, so I’m leaving it as is.  Learning to use WordPress (an open source blogging application) for this blog is my most recent project.  There’s definitely a learning curve, but this far I’ve figured out how to create and edit posts.  As I figure out more, look for changes in the look and feel of this blog, but for now, simple is good. I look forward to sharing some of the more interesting projects I’ve been working on with (and without) my kids.  Stay tuned…