Archive | January 2015

Dual Complementary Optoisolator Logic

Opto-isolator logic. How peculiar and awesome at the same time.


You’ve seen CMOS logic, you’ve seen diode-resistor logic, you’ve seen logic based on relays, and some of you who can actually read have heard about rod logic. [Julian] has just invented optoisolator logic. He has proposed two reasons why this hasn’t been done before: either [Julian] is exceedingly clever, or optoisolator logic is a very stupid idea. It might just be the former.

Inside each optoisolator is a LED and a phototransistor. There’s no electrical connection between the two devices, which is exactly what you need in something that’s called an isolator. [Julian] was playing around with some optoisolators one day to create a weird push-pull circuit; the emitter of one phototransistor was connected to the collector of another. Tying the other ends of the phototransistor to +5V and Gnd meant he could switch between VCC and VDD, with every other part of the circuit isolated. This idea whirled…

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Trigger Zone software – Opens webpages on motion This is my project that competes (freely) with Webcam Zone Trigger. It failed, so I built this in processing.

This is our Tech showcase, and my Trigger Zone shows off some of the features we currently have. We have a few Oculus Rifts (DK1 and 2). We also have a Liquid Galaxy setup that I built.

Get the software on my Github at:

Processing + Kinect = interactive tracking software for cool demos!

I recently tried to use Webcam Zone Trigger for a work project.

This software is for making interactive demo walls, where you walk somewhere around a room, and the monitor updates to the appropriate website, or sends an email, or saves the picture… or something. Essentially, its IFTTT for video data. We were using it for an interactive demo where someone can walk up to new devices and technology, and a big monitor updates with the content we wrote about it, or autoplays a Youtube video.

We already paid for a license ($99 or something like that). And guess what? It stunk.

Well, why did it fail my expectations? When I hooked it up to a Kinect, it displayed the 640×480 depth window as the upper left of 320×240 expanded to 640×480. Below is what it SHOULD have looked like (or what the Freenect does seamlessly):

kinect_depth_imageOk. That looks sane. And BTW, picture shamelessly ripped off of .What Webcam Zone Trigger did was the following:

kinect_depth_image_FAILDafuq? Why is something that claims to work well with the Kinect doing this? Possibly my fault.

Checks Kinect SDK and drivers? Using 1.8 . And it works well with other Kinect apps.

Checks OS integrity. Reinstalls Win7 x64 from scratch. Still same problem.

Check Kinect on Linux. Perfect, no hiccups. No problems.

So the problem is Webcam Zone Trigger. So, what can I do to re-make this program so it opens up a webpage when someone walks through a trigger? Well, I should be able to do it in Processing. I’ve done plenty of demos and proof of concepts in that language before. So I download it and “install” (meaning drag zipped directory to desktop). Then I run Processing and Sketch>Import Library> Add Library and then search for SimpleOpenNi . Remember, I’m doing this with MS SDK on a Windows machine. Else, I’d be using Open Kinect For Processing (libfreenect).

Aaaaand… Voila! Trigger Zone.

After preliminary tests, I made 4 zones around our tech showcase. When you walk up to one, it pops up on the main big screen the details of that device. I also have it set up in the browser to only use a single tab and a single browser.

My next update will to be to add a sound file to play to each zone. That should be very simple. The goal here is to find sounds that are delicate and informative. Long winded diatribes about tech can suck if you’re not interested. Perhaps a ‘ding’ would suffice.

But so far, SUCCESS!