Posts Tagged ‘Bent’

Bent 2010 / Video Mess Tool / Color Me Baddly Breakdown

Wednesday, April 28th, 2010

So, Bent 2010 is over, and as such my arbitrary deadline and excuse for spending time and cheddar on this particular device has been pulled. The above are the final circuits I presented with at the lecture.

The thing on the left is “Color Me Baddly” from the Gerbers below. It’s a color video synth (based on PLLs) which takes a CV in for the color generators (which is peculiar about its input range, to be sure). It also takes a CMOS level input which can invert the color carrier phase by 180 degrees. On the output side it spits standard composite video as well as a CMOS level color carrier (with no sync, blanking, or burst).

The PLL color tracking is pretty good! But not perfect. The PLL keeps lock over a range of a few volts in, and tracks as high as 30+ kHz, which is better than I’d hoped. It took a lot of fudging the loop filter, although the RC calculations weren’t very hard. The invert is a cool input, which originally I just made for the proto because I needed it to to get 360 degrees of color. But in general (not suprisingly) I’m finding that the more inputs you have to things like this the more weird interactions you can get between modulating signals. So I think the invert is here to stay.

The thing on the right is the “Video Mess Tool”. The circuit is different than I originally intended w/r/t the clamping circuits, which had to be made active. The crap you see over in the far right side in the proto area is that new clamp. The clamp ranges changed a little, too. The LT1203 and AD828 and AD8561 are all pretty great ICs and basically do EXACTLY what you’d expect. Even using the opamps in unity gain for the clamps (not recommended) worked without any hitches.

I think this circuit would look a lot cooler with a window comparator — something which muxed many different mess or non mess signals and was smarter about selecting when, and which had a _still_ better series of clamps for restricting signal range. A HSYNC+burst specific monostable following the comparator would also probably not be amiss, although some of the glitchiness would be eliminated. This could be selectable — “sloppy sync” vs “Teutonic Sync” or the like.

The thing in the back is a color synth I made for Christams 2009. It uses varactor diodes instead of a PLL and is its own weird animal. There are pics of that here.

So before finally throwing these guys into the mothballs for who knows what/how long, I made a couple more videos. They showcase some of the more complicated waveforms that can be generated. Neither has any audio involved; both use input from function generators. The above uses the mess tool to mux in a rainbow from the color synth into golf. The lower one is basically two synths being muxed together and inverted all around multiples of 60 Hz, which makes the trippy horizontal band.

Naturally, all this stuff looks better in person; taping an LCD screen with a webcam is not exaclty the height of majesty. And there’s a couple more tech notes on the Narrat1ve youtube channel.

This might be it for this project for awhile, so feel free to write to me or get on the forum if there’s anything else you’d like to know about!

[NOTE: Collin Cunningham of MAKE took a pretty kickass video of my lecture at Bent, and one day I’ll put it up here. Thanks, Collin!]

Xoxo, TB

Video Mess Tool, or, Snuggling With Sandin (for a Bent 2010 lecture)

Friday, April 16th, 2010

The pretty pretty gerbers for a new video tool. This device will hopefully allow you to take all the precious bits of composite NTSC (or PAL, I guess) video and keep them safe, while mucking with the rest of the signal. Sync, blanking, and colorburst are separated with a level comparator, and a mux allows you to inject new signals or perturb the old one. It’s analog, and based on the AD828 op amp, the AD8561 comparator, and the LT1203 video mux/buffer. For one, I hope it works. For two, I hope it looks awesome. Stay posted!

WTPA v1.01 Released at Bent, Now Shipping. More Manuals Forthcoming.

Tuesday, April 21st, 2009

So it finally happened. WTPA is out! I officially dropped the marble at Bent 2009, which was a real blast. To come clean and be totally honest, I actually released WTPA on the Thursday before BENT to the list of faithful WTPA-heads who have been blowing up my inbox for the last few months. You know who you are, and you rule.
To continue to be honest, I have already gotten word back from the first (AFAICT) nerd to not only complete, but MOD WTPA — Mssr Pete Edwards of Casperelectronics. So get crackin.

There’s still plenty of stuff I need to deliver on this site: The operation manual and MIDI implementation chart, the Theory of Operation Manual, schematics and source. They’ll be here this week, at least some of them. I also, more physically, have to get all the orders I’ve gotten out the door. One piece of math I neglected to do: if I’m flying along stuffing parts bags at the rate of one every 5 minutes, and do not pee, sleep, or flip the record, it will take 17 straight hours to stuff 200 bags. Given that it took like One Million hours to get the program and hardware done for WTPA, this isn’t all that significant, but man, is it boring.
Then again, I suppose it’s no more boring than waiting on a whinging prima donna emedded systems nerd who’s too busy making a new prototype analog video synth extention for WTPA to get off his duff and SHIP ME MY ISH.

Rolling to Bent 2009, Dropping Pearls

Friday, April 17th, 2009


Yep, I’m on a jet plane with a bag of art-nerd-bitmagick.
It’s finally happening. Come Back Monday for Business Hours!
In the meantime, some reading:

[Editors note: These are NOT current anymore. xo. TB]

WTPA Component Guide v1.01
WTPA Assembly Guide v1.01