Getting started with OpenCV

[Eric Gregori] sent in an article he wrote for EETimes to introduce the concepts behind computer vision to the masses. As a nice little bonus, [Eric] included a VMware image containing Ubuntu and all the packages and examples necessary to write your own OpenCV apps.

There’s a ton of awesome stuff you can do with computer vision – from automated sentries to keep squirrels away, a kitchen that will tell you when to do the dishes, and automating blindness by mounting a laser on a face tracker, there’s a lot of unexplored territory in the area of computer vision.

Included in [Eric]’s VM image are a motion and line detection example app, an ‘optical flow’ example, and a face detection example. There’s enough here to make a few very interesting projects, so hopefully, [Eric]’s VM image and examples will get your next CV project up and running quickly.

Your guide to building a homebrew 6502 computer

If you’ve ever thought about getting down to bare metal and building a homebrew computer from scratch [Garth Wilson] put up a great primer to the 6502, the same CPU found in Apple ][ computers, BBC Micros, Vic-20s, and the venerable Commodore 64 (a 6510 in the C64, but it’s close enough).

In his guide to building a 6502 computer, [Garth] goes over all the basics – what you want the computer to do, how to decode addresses, and other important technical requirements for getting a homebrew project running.

If that’s not enough, [Garth] directs his readers to the fabulous 6502.org forums  where just about every topic is discussed. The guys on the forum have a standardized I2C pinout for the 6502, allowing noobs to easily connect pre-designed keyboards, displays, and storage devices to their projects. There are a ton of tutorials on the 6502.org site, more than enough to get a homebrew project off the ground.

If you’d like to see what you can do with a homebrew 6502, check out the homebrew projects page featuring a 6502 Nixie clock and CLPD-based 65816 single board computer. There’s a treasure trove of information here, just waiting to be pulled from the vine.

Pinball Stomp: part1

Despite my atrociously short attention span, I’ve always loved pinball. Maybe it is something about all the flashing lights and clunking solenoids. Maybe it is just the simple physics at the center of it all. I’m not really sure.  My kids, however, don’t share my enthusiasm. I suspect part of it is that they never wandered through a fog filled arcade in the middle of the night, hopped up on Reese’s Pieces with a shrinking pile of quarters in their pocket. The other part might be the fact that they have gotten used to the Nintendo Wii and the Xbox Kinect (we just got one last week).

Watching them jump up and down playing an extremely simple and repetitive game with the Kinect gave me an idea. I envisioned pinball projected on the side of my house, the kids jumping up and down in front of it to move the paddles. Keep reading to see how I plan to build it and what I’ve done so far. There’s a full video, but also text of the entire thing.
[Read more…]

How to properly fly with electronics

Some electronics professionals have to fly relatively frequently. One such person, [Steve Hoefer] shares with us how to properly fly with your exposed wires and bits without getting nabbed by the TSA for suspicion of being a terrorist. The article is fairly in depth with tips on how to handle most situations including being pulled aside and put in a tiny room for questioning. Most of it boils down to the fact that you can’t expect the TSA agents to be experts in everything. They see stuff that is slightly out of the norm, they have to follow up. We’re not talking about pat-downs and body scanners here, we’re talking about circuit boards, duct tape, and battery packs.

One story [Steve] shares is especially humorous. He noted that the servos had been disconnected from one of his robots. He wonders, why disconnect them? If they were suspected of being an explosive, they shouldn’t have messed with them. If they weren’t… why did they un-plug them?

Want a two person self destruct button, but tired of pesky microcontrollers?

We all know that our precious cruisers/warships/assets can not fall into the wrong hands, and what better way to assure that information security than incorporating a self destruct button into the design? While the general premise is simple enough the only real way to make sure some crazy space-virus can’t infect your captain and force him to destroy your ship is to add a two button security system! Wait, what if it’s a computer virus?! Well [Andrea] has it covered with this two hand hand control switch. We guess you could also just use the scheme to flip on a dangerous piece of equipment, since it forces the operator to remove both hands from the machine to operate the buttons, but where is the drama in that?

The buttons are timed using a combination of voltage dividers and caps to activate transistors, one to activate the 555 timer and another to disable the button input after a half second or so. Since it’s all resistor capacitor timing your circuit may require just a bit of tuning (or precision components) to get everything right.  There is a bit of an issue with using two people to trigger the output, as the second button actually operates the output relay directly. If the second button is held it will only remain active until the timer’s output is triggered, but if your second in command gets cold feet and releases the button before the core goes thermo, well, you’ll have an embarrassing jog to the escape pods.

Check the video after the jump to see [Andrea] fiddling around with the switch.

[Read more…]

Updating your workspace for more organized and efficient hacking

workspace-upgrade

If you’ve ever looked at one of [Todd Harrison’s] teardown or how-to videos closely, you would likely notice that his work bench looks like a standard hacker workspace. While we all try to keep our work areas clear of clutter, it’s not uncommon for components to pile up, cords to tangle, and things to get messy. [Todd] decided it was time to get a bit more organized, so he recorded a video showing how he went about the process.

Part of [Todd’s] work revolved around adding shelves to his bench so that he didn’t have measurement equipment stacked on top of one another. He also spent a good amount of time adding 30 additional plug sockets to his work space, replacing the single socket he had been struggling with for years.

Obviously this is not really a hack in and of itself, though this sort of reorganization is an important to efficient hacking all the same. We like the fact that [Todd] took the time to explain his process and materials in great detail – it will no doubt be helpful to those new to hacking.

Continue reading to see [Todd’s] video in its entirety, or swing by his blog for more pictures and details.

[Read more…]