I’ve been wanting to tinker with RGB LED matrix for a while, and finally was able to do so earlier this month. It was fun programming some effects, game of life etc. on a 8×8 matrix using Arduino. Here is a Christmas ornament that I programmed. It shows a color changing star followed by scrolling … more
In early September, Kevin built a plotter using NXT, using the design from the book “The Unofficial LEGO MINDSTORMS NXT 2.0 Inventor’s Guide” by David Perdue & Laurens Velk. It is an amazing book with lot of good ideas and designs. I was not content with the NXT 2.0 text and the graphic it printed … more
Picking up from my last blog post, where we observed 255 = 15 x 17, I present to you some cool observations from the telescoping multiplicative series obtained from 2^n-1.
In CSS, when I need a shade of grey, I often use hex rgb like #cccccc, #eeeeee etc. (or in short form, #ccc, #eee) I posed myself a question today: If by using repeated hex notation, do we evenly divide the grey space from #000000 to #ffffff? What I found was very interesting. Let us … more
Just realized I did not post any blog entries this whole year, so let me rush! I was casually looking for properties of the number 2014 this morning, and stumbled on to this neat property: http://oeis.org/A083074 – n^3 – n^2 – n – 1. When I looked up for n, a pleasant surprise! It was … more
I wanted to create a progress indicator that would show completed stages in a shade of green. Initially I was thinking of using Raphaeljs, but this task seemed solvable only by using CSS. So here is a simple jsfiddle I came up with showing how it can be done:
I received a Raspberry Pi as a gift (Thanks T.H!) last Friday and couldn’t wait to tinker with it. In case you are wondering, Raspberry Pi is a credit card size computer that is going to revolutionize education & computing. Step 1 was a trip to Fry’s to pick up an SD card that would … more
I programmed 5 Christmas tunes in Arduino, and also made a synchronized light show with some special effects! It plays the following tunes in sequence after each key press: Jingle Bells The First Noel O Holy Night We Three Kings What Child is This Merry Christmas! Here is the source code if you are interested: … more
Here is a wordle I created based on the stats found in w3techs site: Note: The sizes are indicative of the relative popularity and are not to scale.
Well, this was my plan – to create an extremely simple virtual piano with Lego Mindstorms, just by using the ultrasonic sensor in the manner below: To play the correct frequency for the detected key, I first tried a ladder if-then-else within the Mindstorms visual programming environment, and it absolutely tanked! For every if-then-else path, … more