Testing with lasers from AIXIZ (2)

I've mailed a couple of times with AIXIZ and I've to say: "Nice guys over there!". The laser I used to test my setup, was somehow broken and AIXIZ offered to send me a new one! Very nice and good job of AIXIZ! I just did another test with another laser and the result is perfect! The laser is extremely powerfull and bright as you can see in the image. In a couple of days I'll try to hookup the laser to the prototype of the touch table so I can start doing some real tests.

Chuck form AIXIZ told me that one can connect the 780nm 25mW 5VDC infrared laser directly to +5v. When you connect your laser, make sure to use a stabilized power supply, or use a LM7805 to stabilze the input. When you use a LM7805, make sure you set your power supply to a voltage which is a higher than 5v so the LM780 can stabilize it.

20 April 2010

openFrameworks freakDay 8 / 9 ? @ Amsterdam

Last Sunday (18-04-2010) we another openFrameworks freakDay with our newest member Mattijs Kneppers who created an event sequencer while trying openFrameworks for the first time.. really amazing work! In a couple of weeks we'll organize another openFrameworks freakDay in amsterdam. You can contact me if you want to join! of course you're more than welcome!

20 April 2010

Touch Table inlays for lasers

Tim created an inlay to keep the lasers in their place for the laser based touch table we are working on. The inlay looks really good even when it's just a prototype and a "quick" solution to test how we can position the laser in the most suitable way. We also did a test with another laser to check if the other laser we were testing with so far, was broken. The new laser seems to be much better and gives an extremely sharp dot. I've contacted AIXIZ, where we bought the lasers, and am waiting for some technical specs for the 780nm 25mW laser we want to use. A nice thing to mention is that the ultra cheap Trust webcam (WT-1400), we're using to check if the lasers are working is sensitive to 780nm IR.

17 April 2010

Testing with lasers from AIXIZ

Working on a touch table project I'm testing 780nm 25mW lasers from AIXIZ at the moment. Though somehow I cannot get a bright line from the lasers. I've tested only with two lasers and got the same result sadly. I'll try to use another laser later, or next week and get better results hopefully. I found some links which describe the same problem. Also some people wrote very nice posts about using lasers for multi touch.

• http://nuigroup.com/forums/viewthread/8650/
• http://nuigroup.com/forums/viewthread/9386/

16 April 2010

Edge Bundling v2.

Just a couple of new images from my edge bundling code.

14 April 2010

openFrameworks Freakday @ Amsterdam

Last sunday we had an openFrameworks meeting at Tim's place near the Bijenkorf in Amsterdam. Theo gave a talk about the newest iPhone version which, again, is great! It simplifies iPhone development and keeps the openFrameworks paradigm! Simple and fast! I did some tests with, as stated by the paper I read about it "Hierachical Edge Bundles: Visualization of Adjacency Relations in Hierarchical Data" and "Force-Directed Edge Bundling for Graph Visualization" by Danny Holten.

Together with Tim, Rick , Martin, Theo and myself we had a very nice, spontaneous oF FreakDay.

12 April 2010

Hierachical edge bundling of network data

Playing with Force-Directed Edge Bundling for Graph Visualization. Not working yet, but the result is nice; as most unexpected things.

12 April 2010

Infrared webcam

As I'm still working on my multi-touch table I've created an infrared webcam to do some tests. My table will use IR lasers as this should give the best results. I heard of projects which got the same feeling as the iphone. I have two webcams: an old Logitech Quickcam Pro, and a Trust WT-1400. I started with the Quickcam but found out that the IR-filter I wanted to remove is a coating on the lens itself. I don't have the tools to remove that coating and leave the lens intact. Therefore I gave my Trust webcam a try wich was very simple to turn into a IR cam. The only thing you should be careful of when removing the IR filter (the tiny square glass with shiny surface), is that you only remove part of the plastic body so you can put everything back into it's place again. Basically you get a sharp knife and remove a couple of rings from the lens "holder". Then using a sharp thing; I used a screw driver, you popup off the lens, remove the IR filter, create a light blocking filter using a floppy disc and put everying w/o the IR filter back together. I was suprised when I hooked up my cam; the light blocking filter, which I made from a floppy disc, works extremelly well. See some of the photos I took while creating the cam. Note that the rounded lens, with the shiny surface is the lens with an IR coating.

10 April 2010

Barnes Hut Algorithm

I'm working on a magnetic particle system and got my first version working last week. The next step is to improve the particle system so I can use more than ~300 paticles with a framerate higher then 30fps. The problem with particle systems and particle-particle interaction is that we have O(n²) problem.. This just means that the number of computations increases extremely when adding more particles. When we have 2 particles, the number of particle-particle computation is 2², when we've got 300 particles, we've got 300² = 90.000 checks we have to perform for each frame.

Click on read more to read the rest of the post.

7 April 2010

Exploding MAC battery

After 1.5 year the battery of my mac book puffed as how they called it. I never heard about it but it seems to be a regular problem. Sadly Apple just ignores this problem which is problem due to heating. I had to buy a new battery ... I hope this one will not puff

6 April 2010