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[mutsop]

Hi,

I was always intrigued by interactive tables. So I thought that would be my main goal in about a year (or less).
I suppose 1 year is doable for someone who has only basic knowledge of electronics but very good knowledge in programming (.net).

And as you might be thinking, I'll be using netduino for my projects. As of now I'm still waiting for it to be delivered.

So my main goal is to get a table with at first one simple tetris game. So the amount of leds I'll be using in my end project will exceed the 4000 I think But for now I'll be doing tests with around 100 to 200 at max.

Also I found this really cool led table from evilmadscience, using passive/active IR sensors. This might be a nice addon if my tests would work.

So my question to you: is this doable with a netduino?
activating a massive amount of leds (over 4000) would this generate a risky amount of heat? What about power consumption.
Also what active IR sensor could be used (as on the evilmadscience tables)?
Anything else I should be worry about?

PS: I'm not sure if this may be asked about evilmadscience... if not terribly sorry for that.

[Chanler]

Wow, that's a project and a half.
I'm sorry I can't directly answer your question, but have you considered something like an interactive game table instead?
http://madbrewlabs.com/rise-digital-game-table/
Basically they're using a projector mounted underneath and a wii remote connected to a pc. An IR pen is then used to interact with the screen.

[athos76]

I've been researching the same project as the EMS table. I love how they call it open source, but don't give any info on how its made. I've narrowed down some of the components, Depending on how I make my table it will have about 4200 leds...

I'm working on a smaller wall art design as a test bed, somewhere in the 2ft x 2ft range... I want it to be motion reactive (wave a hand and it twinkles) and to switch to music activated. I'd like the switch to be a physical one between two Arduino boards if possible.

The one thing I like about the EMS table is that when you wave your hand, the effect ripples out.

I've almost been tempted to order a panel just to find out how it works.

[trialex]

I love how they call it open source, but don't give any info on how its made.

What? This looks fairly comprehensive to me

http://www.evilmadscientist.com/article ... blecircuit

[Mee_n_Mac]

So my question to you: is this doable with a netduino?
activating a massive amount of leds (over 4000) would this generate a risky amount of heat? What about power consumption.
Also what active IR sensor could be used (as on the evilmadscience tables)?
Anything else I should be worry about?

Do-able ? Yes I'd think so though I've not put a ton of thought into it. As for power well it depends, mostly on how bright you want the LEDs to be. If you used some bright LEDs, at 20 mA each, 4000 would be 80 A if all were turned on simultaneously ! But nobody does that, they use something like a MAX7219 driver and multiplex the LEDs so only a portion of them are on at any one time, but scan them so fast your eye can't see when they're off. They just appear dimmer. Even an 8:1 ratio (a duty cycle of 12.5%) reduces the amps needed to something reasonable for a computer PS to do. And of course reduced power is reduced heat. The above 4000 LEDs, all on simultaneously, would dissipate about 300W.

As for a "active" sensor ... I don't think they use one per se. My guess is they use some of the LEDs as photodiodes. Some LEDS are turned on, perhaps just briefly, and the surrounding LEDs are "off" and used to sense the light bounced off your hand, etc. No light sensed means nothing above the table at that locale.

What I would suggest is you first do some experiments with various LEDs and drive currents and determine what duty cycle gives you the desired light level.

BTW are you thinking of single color LEDs or RGB ones ?