Binary, hexadecimal, colors, and 3D


Today we had what felt like a very successful class.  We’ve been working on 3D topics, so I started by explaining about different 3D technology like anaglyph, polarized filters, and the processing by the eyes and brain (3D with only one eye).  We used the XOs to take some stereographic images and started trying to convert these to anaglyph (red/blue) 3D images.  We took a theoretical break this time to talk about how pictures are represented in computer files.  First, I had the kids define what a picture is.  The definition they came up with is that a picture is a organization of colors into shapes to represent something so it can be saved for later.  Then I asked the kids how the computer knows what colors are.  The kids were familiar with mixing paints, so I explained the difference between mixing colored pigments and mixing colored light.  Then I had the kid figure out how colors could be specified as numbers.  They seemed to understand how colors could be specified as numerical amounts of basic colors (read, green, and blue).  But then, I tried to challenge them a bit more by asking how they can represent numbers in terms of 1’s and 0’s.  This is the part that kind of surprised me how well they picked it up.  Even one of the kids that had trouble with fractions in school even seemed to get it (maybe we should start kids out with number theory instead of fractions and multiplication tables–I hated multiplication tables when I was a kid).  To get them started, I used the old joke about there being 10 kinds of people in the world, those that understand binary, and those that done (10 in binary is 2 in decimal).  Part of what was easy for them is that it was just enumerating binary and then showing them the same thing for hexadecimal, only up to 17.  Then I had them google “hexadecimal color” and they found the familiar triplet of 2 digit hexadecimal color codes.  I had them google it because I don’t like giving away the answer without doing some work on their part.  To make sure they got it, I made them tell me which of the #123456 digits in the color code represents red, green, and blue (actually it’s pretty easy that 12 are red, 34 are green, and 56 are blue–the same order one would expect–but having them compare the colors in the palette with the numerical code was a kind of hands on thing that made them see how the colors can mix).  I got into a slightly more advanced topic, that each color scale has 256 (0-255) values, but only some people got the fact that FF (hex) == 255 (decimal).

Decimal to binary to hexadecimal conversion is easy if you go step-by-step, just adding one to the previous number:


Color codes and the color palette: connecting the dots/pixels 🙂


OLPC Sighted in the Wild

Last week we brought the OLPC’s to Kenneth Hahn Park in Baldwin Hills.  The computers played a limited role of documenting the hike through the park in pictures.   The kids were surprised to learn that there were a number of edible plants like pink pepper and fennel/lincorice.  There was also some  wild cotton, sage, and California sagebrush, a.k.a. Cowboy Cologne, a number of bugs, and sweeping vistas of the city.

View above La Cienega

All the pictures above were from the OLPC.  Below are some others from phones:

Playing with OLPC/XO

I wasn’t able t0 meet up this week because of car trouble (sorry guys), but I have gotten some time to play with the XO and see what it (and Sugar) are capable of. I knew the system was built on Linux, so I decided to just start plugging stuff in and see what worked. Initially I tried:

  • Kensington USB wireless mouse
  • Dell USB wired keyboard
  • Microsoft USB LifeCam HD 6000

These worked fine (although the webcam is a bit tricky since the XO uses its own webcam until you restart it, unless you tell it otherwise).

I also spent some time tweaking the source code for the ‘record’ app, to try and trick it into using a larger resolution for the webcam. Alas, even though it was simple to start editing the Python source code (which I backed up first of course) I could not get ‘Record’ to work with larger videos. I could play video fullscreen from either the built-in or Microsoft webcams from the console.

I also played with the software some, especially the composer app and ‘Measure’. ‘Measure’ seemed really interesting since it seems to have the ability to measure voltage and resistance, so maybe it could be used as an oscilloscope. Or even an amp meter too, with some extra circuitry.

Lastly, the XO seems like a good robotics platform. I think you could use it with an Arduino or a TeensyUSB to build some cool projects. It doesn’t look like there’s a Sugar GUI for either yet, but both have Linux console utilities.

OLPC & Khan Academy: Future of World Education

As we observe, world of Entertainment and Music is already highly personalized, the iPods and earphones  — and so will be Education!

Today, it’s common knowledge that effectively among the largest shopping mall in the world is, that among the largest marketplace in the world is along with now emerging

Similarly, Khan Academy is emerging as the largest academy in the world — and FREE! Thanks to Salman Khan’s vision now being supported by Gates Foundation and several philanthropists.

Of course, schools are good for discipline, social interactions, personal and emotional development,  peer and friends network,  extra-curricular activities sports, music, etc. — and hopefully lasting impressions of good teachers! Too bad –  so many layoffs , so much teacher turnaround!

That said, for any serious promise, or for any real major hope for Urban education reform — in my opinion — fortunately, Khan Academy is emerging as a truly student-centric, self-paced learning system – from catchup-enabling to cerebral-catapulting!

Khan Academy offers high quality education content over the Internet –  anytime! anywhere!! and free!!!  It’s style is self-paced catering to a broad range of students ranging from novice to magnet levels.

Khan Academy connects students, coaches, and parents / guardians! Anybody can watch the educational videos. With just a gmail or facebook id, a student can start practicing, and register teacher, and/or parents / guardians as coaches so they may monitor a student’s progress and intervene when necessary.

Even more important, Khan Academy brings together students from all over the world as we notice from the comments section where more proficient students possibly from a more affluent demographics trying to encourage and enlighten the students from possibly underserved communities! It’s wonderful to witness global peer outreach — and the promise of equality!

Khan Academy knowledge map begins with basic addition and goes up to Calculus, Linear Algebra,  Advance Placement test prep assist, and  Cosmology and Astronomy, Brain Teasers, Economics, and beyond!

Amazing! Yet challenges remain … irony is that students who need it most in Urban Schools can not access Khan Academy easily because of financial challenges — still need a computer or a smartphone and Internet connectivity! Good news is that OLPC XO  seems poised to fit nicely to bring Khan Academy content to students all over the world! The content is already being translated to Spanish Khan Academy Espanol and several languages!

A game-change thinking and awareness expansion is needed in the Urban Schools community among parents and the Educational system — superintendents, administrators, policymakers, principals, and teachers to make appropriate fund and time allocations and prioritize so new Urban America can learn!

* Current Status: Presently, I have been able to launch Khan Academy on XO on both Sugar Browse as well as Firefox on Gnome. Exercise components seem to work. I still need to get the videos to work in terms of Adobe Flash +- Gnash components on Sugar Browse as well as Firefox.

TamTamMini, TamTamJam, SynthLab and OLPC at Audubon Middle School

I went in to my first day volunteering at the Famli after school program at Audubon Middle School knowing very little about OLPC, so I asked the kids to show me their  favorite programs.  TamTamMini and TamTamJam were two of the programs they showed me and it was pretty impressive how much they already new about the programs.  I was a little frustrated because on the OLPC there are no help pages incorporated with the applications (there is documentation online, but I was looking for the familiar help on the menu bar).  But soon after I was pressing random buttons and clicking things and figuring things out like a kid. I also played around with the synth lab b/c the icon (sine wave) caught my dsp (digital signal processing) attention.  This application I understood better b/c I’m familiar with dsp and I worked on the clam project which uses a similar network metaphor for the signal processing components.

For all the benefits of the hands-on approach, the programs have complexities that really require some explanation.  Caryl, to the rescue, provided me with some useful links that I will post here for future reference.

The following link is a video that introduces TamTamMini.  The main non-intuitive thing was which keys on the xo map to which piano keys.  Also I noticed that the version on the video seems to be different because on my xo there’s no sound patches from synthlab :

The following link is a wiki page that gives an overview of this family of programs (TamTamMini, TamTamJam, TamTamEdit and SynthLab):

The following link has kids giving a recital using TamTamMini:

The following has an orchestra of xo’s… Hey where’s my lab coat?

Well, I think it will be fun playing with these programs with the kids.  Some of them already play instruments and music is a part of Torre’s curriculum.  I think that once I figure out SynthLab, I’ll be able to explain some acoustics and phonetics to the kids.

New Beginnings

Sometimes things don’t quite work out the way they are planned. Two years ago the FAMLI/OLPC project at Audubon Middle School got it’s start with 10 contributors  Program XO-1s from OLPC.  The plan was to start a lending library and repair center, but a variety of obstacles  got in the way.

The logistics of sending the laptops home with children in a community where they might be stolen on the way could not be figured out.  There were no broken machines to repair. The volunteer who started the project moved away.

But the students quickly adapted to the XOs and dreamed of exchanging letters with other children using XOs all over the world. They even named the computers after different countries. They became experts at using the mesh to share Activities and explored many of the Activities and special features of the XOs. They never lost their hope of doing more.

A few weeks ago a call for volunteers went out on the OLPC-SoCal Mailing list. The response was excellent and a week ago three new volunteers, Raj Baberwal, Abe Kazemzadeh, and Steven Pease met with me (OLPC Support Volunteer, Caryl Bigenho) and FAMLI director, Torré Reese, to plan the future of the project.

Off to a new start! New volunteers Abe, Raj and Steven with Caryl Bigenho from OLPC and Torré Reese from FAMLI

The volunteers will be meeting with the students once a week for starters, with other times as things come up. Each of the volunteers took home an XO to explore its possibilities and have been discovering some very interesting and valuable things about the machines and the Sugar software. They will be blogging here to tell about their experiences with the XOs, Sugar, and the students.

We have recently made contact with a project in another country and hope to find others soon. Instead of exchanging individual letters, the students will be collaborating to produce an e Newsletter to exchange with students in other countries.

Now the studetns will finally be able to get a start on their repair center with 3 machines I have from the old M-Stock from the G1G1 program and will be applying for other damaged machines to practice on. Finally, we plan to have the students share their experiences as guest bloggers on this blogspace.

So, things haven’t worked out as planned, but, with the help of our enthusiastic new volunteers we have great hopes that it will be better than we ever could imagine.