Ariel’s Portrait
Sai Sriskandarajah, Matt Chmiel, Teresa Porter and I created the Human Empowered, Pixel Optimized Camera Rendering Asynchronous Process for the Physical Computing without Computers course at ITP. This project recreates the digital camera rendering process, but instead of using microprocessors, human beings are enlisted to encode, digitize and render the image.
Matt Encodes
The first step in the process was to divide the image into individual pixels. We discussed and experimented with several possibilities, including dead reckoning, a latticework direct imaging grid and windowpane method. Finally we settled on using a medium-format camera’s focusing screen, with a grid drawn on it so that it would be easy to distinguish where each pixel was, and comfortably read off values. Next we experimented with pixel size and bit depth. A 8 x 8 grid produced too low resolution for an image to be interesting. We then attempted a 16 x 16 grid which too longer to read off, but created a reasonably recognizable portrait image.
Filled imaging grid
Continue reading ‘Human Empowered, Pixel Optimized Camera Rendering Asynchronous Process’
Heather, Zach and myself created four logic gates out of Legos scrounged from various Lego Technics vehicle model kits. Full information and pictures after the jump…
Continue reading ‘Lego Logic Gates’
Heather, Zach and myself created a two-bit adder using laser-cut foam core board, wire and marbles. We initially tried a “boat” design similar to the one used in our one-bit adder. The boats didn’t quite come together properly, so we decided to try Zach’s secondary design that was cut at the same time. It worked beautifully, as long as we tilted the board back to at least a 75 degree angle so that the marbles didn’t fall off the front of the flip-flop gates.
The right side of the adder is the least significant bit. The top flip-flops indicate binary zero or one. The bottom ones are carry bits, and each one is intended to drop a marble onto the next most significant top flip-flop, thereby carrying the product of adding one to one up to the next place.
This design can be extended to any number of bits. Currently the marbles fall off the board or stay on the flip-flop levers. A future version could include holes in the board and a collection system that returns the marbles to the top of the adder, for reuse. It would be fun to add bells to give an acoustic bling to the project. Maybe whistles and a music box too. More pictures after the jump…
Continue reading ‘Two-bit Mechanical Adder’
Heather, Zach and myself created a one-bit mechanical adder (with a carry function) that runs on marbles. I found the basic design online and we modified it to our purposes. Zach and Heather used cardboard, foamcore and genius to prototype the flip-flop mechanism, then mounted each on a cardboard box, adding ramps and chutes to carry the marbles through the system. The flip-flops tilt to the left to indicate zero, and to the right to indicate one. So the top indicator denotes binary 1, while the bottom indicator indicates the carry bit, or binary two. Here’s a movie that I made of the adder in action, before I decked it out in rave-wear.
The plan going forward is to implement the design in wood, with additional bits (maybe eight or 16) and a subtraction function. It would be interesting to add a crank mechanism that carried the marbles back up to the top, perhaps in a single turn. This would allow for multiplication.
Matt, Teresa and I built a full-scale Stirling engine for use as a power source for a future mechanical computer. Stirling engines are external combustion engines. This one will derive its power from pressure differences created by the exchange of heat between hot and cold water compartments.
We’re a bit concerned that the crankshaft may not be straight enough to maintain balance for the flywheels. Actually this is part of an overriding concern about how much power the engine will provide. We’re pretty sure it will be able to spin itself, but not clear on how much torque will be generated. It’s essential that the engine generate excess energy so that it can be connected to the mechanics of our yet-to-be-designed computing system.
Cans and Piping for Heat Exchange Pistons
Crankshaft and Flywheels
Matt, Teresa and I created a paper clock from a kit using X-Acto knives, white glue and human tears. While the tolerances weren’t close enough for it to actually keep time, we learned quite a bit about the internal mechanics of timekeeping, and spent 20 happy hours together in the Physical Computing lab. Clocks rock.
Overview of the Project
Raw Wheel Parts
Getting it Together!
