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Laser Modem with an Arduino Microcontroller

esalazar — Mon, 11 Aug 2008 20:03:26 -0600

Serial data transition from a Arduino controller using a standard red laser, photo transistor and an instrumentation amplifier.

This started when I ordered an IR led and phototransistor pair from Spark Fun along with some spare ATMega168 microcontrollers. I first experimented using the IR led to transmit 2400 baud serial to the phototransistor. I programmed my Arduino Diecimila with the sample serial program altering the baud rate and allowing it to run in a continuous loop.

Laser Modem with an Arduino Microcontroller

esalazar — Mon, 11 Aug 2008 20:03:26 -0600

Fractal Mountain Generation with Qt and OpenGL

esalazar — Mon, 04 Feb 2008 21:29:14 -0700

The purpose of this project is to create 3d mountain terrain using a recursive midpoint displacement formula. For this project I decided a GUI would be useful, that way manipulations could be seen in real time. This would require a 3d rendering package. My choices were DirectX, OpenGL and Java3d. Since I prefer to do my development in Linux, DirectX was ruled out. I have not been very impressed with the performance of Java3d so that left me with OpenGL. After deciding on my rendering package I needed to choose a language and a GUI framework. GLUI is an excellent framework for leaning OpenGL, but lacks control over the layout of the interface. So I decided on QT by Trolltech which was just recently acquired by Nokia.

Midpoint Displacement Formula

Fractal Mountain Generation with Qt and OpenGL

esalazar — Mon, 04 Feb 2008 21:29:14 -0700

Using a packet sniffer to track games/applications phoning home, and how to block them via the routing table or the hosts file

tdavis — Mon, 07 Jan 2008 23:11:12 -0700

The other day I was trying to play an old game I bought some time ago on my LAN. I was just trying to enjoy a little cooperative bot killing fun with my buddy, but for some reason, the game kept telling me my 'master key' or something along those lines didn't check out. Needless to say I wasn't happy with it... I bought this game... and maybe I wasn't supposed to play it on two machines at once... but at the very least I certainly didn't want it phoning home for a simple LAN game, a game mode where no master server or internet should be required.

So I decided to see what my 'game' was up to. A quick download of Wireshark (formerly Ethereal) and an even quicker packet sniff and sure enough I could see where my 'game' was initiating connections and across what port.

Using a packet sniffer to track games/applications phoning home, and how to block them via the routing table or the hosts file

tdavis — Mon, 07 Jan 2008 23:11:12 -0700

Encoding an image to sound

esalazar — Mon, 07 Jan 2008 20:36:41 -0700

The purpose of this project is to encode an image to a sound that can be viewed with a spectrogram. For some time I have known that musical artists have encoded pictures into their music. Most notable of these is artists is Aphex Twin. Luckily I had a copy of Windolicker and a great visualization program Sonic Visualiser. After looking at the images I decided it would be cool to try and encode my own images. I saw a few programs available, but decided it would be a better challenge to write my own program from scratch using Perl.

Spectrograms

Encoding an image to sound

esalazar — Mon, 07 Jan 2008 20:36:41 -0700