From Wikipedia: Force-directed graph drawing algorithms are a class of algorithms for drawing graphs in an aesthetically-pleasing way. Their purpose is to position the nodes of a graph in two-dimensional or three-dimensional space so that all the edges are of more or less equal length and there are as few crossing edges as possible, by… Read More: Force-Directed Circuit Board Footprint Autoplacement »
I bought a used lathe. It’s a Craftex B1979C, which seems to be nearly identical to a Craftex CX704. Similar to many such mini lathes, actually, with varying swing lengths. The previous owner explained, a little bit sheepishly, that he tried to cut steel a little too hard, and burned out the AC motor.… Read More: Strange New Bedroom Furniture »
I haven’t properly built anything with my hands in a while, so it’s time. I mocked up a few lamp ideas, and this one seemed fun. Really, really rough mock-ups. That was neat looking, so I fleshed out the hinge section, which I expected would be the hardest part to figure out and… Read More: Brass Lamp »
Voltage glitching, also called fault injection, is the process of dumping the energy on a microcontroller’s power rail very briefly – Just enough to cause a glitch, where it skips an instruction, rather than causing a brown-out-induced reset. I first learned about the technique in connection with the Chip Whisperer, which is an FPGA-based board… Read More: Dumping Firmware With a 555 »
Here is a brief overview of how light and colour work, in the context of LED lighting. We’ll mostly be discussing the CIE 1931 colour space, with reference to the chromaticity diagram, shown below. This is the 1931 version. Newer versions that look slightly different have come out, but the general intent is the same,… Read More: Chromaticity »
I’ve been into timelapse photograpy for a long time, often focused on driving the cost down by hacking existing digital cameras. That follow up post (already written almost two years after the original work) promised project pictures that were never delivered, so here, I went spelunking in some nearly decade-old backups for them. … Read More: Watching Plants Grow »
This is a fairly old project that I just wanted to document to current-state and provide a conclusion. See here for the old logs. Some of the original design goals for this project were ease of design, and manufacturabilty. Ideally, the design would be clean and turnkey enough for me to be able to… Read More: POV Globe – Electronics »
I’m on another clock kick. More of a wristwatch this time. The dream is to have a couple metal bars floating in oil, and when a button is pressed, they float to the appropriate hour and minute positions. For an initial version, I’m paring this way down to just a single indicator hand. On the… Read More: A Matter of Time »
This is a follow up from Infin1D, Rev 0.5, where I threw together a proof of concept in a few hours. This is the one where I spent some actual time on it and built a base that, while still quite rough, can be incrementally improved to arrive at a final product. This miiight have… Read More: Infin1D »
I’ve used a lot of solder paste, usually from one of those big syringes. When depositing little tiny blobs of solder on a few hundred little tiny pads, two problems emerge: That big syringe has a big plunger that really starts to hurt the heel of your hand after a lot of usage, especially when… Read More: Syringe Full of Lead »