Another home-built laser projector

From my Google Reader:

[Jarrod] sent us a link to this home-built laser projector after seeing a different projector that we featured yesterday. This system is fundamentally different. [ChaN], who finished the project several years ago, didn’t use a loudspeaker to move the mirrors, but instead build his own closed-loop Galvanometers. Two of these are controlled by an ATmega64 to produce incredibly clean and accurate vector images. It’s not just the images that are impressive, his hardware is laid-out with skill and forethought that make hiding it in a case a sacrilege.

Comments

uSleep on windows (win32)

I am facing a terrible issue regarding timing on windows. Googling arround, I've found those infos: Using QueryPerformanceCounter and QueryPerformanceFrequency APIs in Dev-C++ ( http://yeohhs.blogspot.com/2005/08/using -queryperformancecounter-and_13.html ) QueryPerformanceCounter() vs. GetTickCount() http://www.delphifaq.com/faq/delphi_windows_API/f345.shtml How to time a block of code http://www.cryer.co.uk/brian/delphi/howto_time_code.htm And Results of some quick research on timing in Win32 http://www.geisswerks.com/ryan/FAQS/timing.html With that I'm trying to write something like a uSleep function for windows: # include<windows.h> void uSleep ( int waitTime){ __int64 time1 = 0, time2 = 0, sysFreq = 0; QueryPerformanceCounter((LARGE_INTEGER *)&time1); QueryPerformanceFrequency((LARGE_INTEGER *)&freq); do { QueryPerformanceCounter((LARGE_INTEGER *)&time2); // }while((((time2-time1)*1.0)/sysFreq)<waitTime); } while ( (time2-time1) <waitTime); } T

More trickery with gnuplot dumb terminal

In my post " Plotting memory usage on console " the chart doesn't pan the data. Now, using a named pipe, the effect got a little bit nicer. First, we have to run the memUsage.sh script to get a file filled with memory usage info: ./memUsage.sh > memUsage.dat & Then we have to create a named pipe: mkfifo pipe Now we have to run another process to tail only the last 64 lines from the memUsage.dat while [ 1 ]; do tail -64 memUsage.dat> pipe; done & And now we just have to plot the data from the pipe: watch -n 1 'gnuplot -e "set terminal dumb;p \"pipe\" with lines"' And that is it!

The prefuse visualization toolkit

Navigating on the silk icons web site , I've found an interesting use of the Prefuse Visualization Tool Kit. “Prefuse is a set of software tools for creating rich interactive data visualizations. The original prefuse toolkit provides a visualization framework for the Java programming language. The prefuse flare toolkit provides visualization and animation tools for ActionScript and the Adobe Flash Player.” They have some nice visualizations on their gallery. I hope to soon use this tool kit on some projects on my job. Bellow is the screenshot of one of the projects which had used Prefuse: This particular screenshot is from the project: Voyagers and Voyeurs: Supporting Asynchronous Collaborative Information Visualization by ( Jeffrey Heer , Fernanda B. Viégas , Martin Wattenberg ) . Following Fernanda B. Viégas and Martin Wattenberg web sites, I've discovered that both worked on the Many Eyes project for IBM . Perhaps, Prefuse is the ancestral of Many Eyes... ;-) As is i

FilipiVianna

Search This Blog