Retrotechtacular: First Laser Transmitter Built 50 Years Ago

May 14, 2013 by Mike Szczys 15 Comments

helium-neon-laser-transmitter

Most of the time we feature hokey film footage in our Retrotechtacular series, but we think this hack is as cool today as it was fifty years ago. [Clint] wrote in to tell us about Operation Red Line. It was an experiment performed May 3rd and 4th, 1963, which means the 50th anniversary just passed a few weeks ago. The hack involved sending data (audio in this case) over long distances using a laser. But back then you couldn’t just jump on eBay and order up the parts. The team had to hack together everything for themselves.

They built their own helium-neon laser tube, which is shown on the right. The gentlemen involved were engineers at a company called Electro-Optical System (EOS) by day, and Ham radio enthusiasts by night. With the blessing of their employer they were able to ply their hobby skills using the glass blowing and optical resources from their work to get the laser up and running. With that side of things taken care of they turned to the receiving end. Using a telescope and a photomultipler they were able to pick up the beam of light at a distance of about 119 miles. The pinnacle of their achievement was modulating audio on the transmitter, and demodulating it with the receiver.

[Clint] knows the guys who did this and wrote up a look back at the project on his own blog.

Master Lock Auto-cracker Built As Coursework At University

May 14, 2013 by Mike Szczys 58 Comments

We love the beginning of May because the final projects for college coursework start rolling into our tips line. Here’s one of the latest, it’s an automatic Master lock combination cracker which was built by [Ross Aiken] and his classmates as part of their ECE453 Embedded Microprocessor System Design class at the University of Wisconsin – Madison.

We’ve talked about the ease with which these locks can be cracked. But [Ross] points out that the resources we linked to before are flawed. To get the combination as quickly as possible the team has implemented an algorithm discussed here. Their machine uses a stepper motor to turn the dial with a big solenoid to pull on the shackle. The system is sensitive enough to detect the “sticky” spots of the lock, which are then used to narrow the number of possible combinations before brute forcing the combination. As you can see in the video after the break, the shackle moves slightly when pulled after an incorrect combination. The long vertical pin near the solenoid will pass through an optical sensor when the correct combination is found.

Do you have your own final project to show off? What are you waiting for, send us a tip about it!

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GoPro Hack Delivers Live Video Feed For Piloting Your Quadcopter

May 13, 2013 by Mike Szczys 43 Comments

The GoPro line of HD cameras seem like they were specifically designed for use with quadcopters. We say that because the small, light-weight video devices present a payload which can be lifted without too much strain, but still have enough horse power to capture video of superb quality. Here’s a hack that uses the camera to provide a remote First Person View so that you may pilot the aircraft when it is out of your line of sight.

The camera in question is a GoPro Hero 3. It differs from its predecessors in that the composite video out port has been moved to a mini USB connector. But it’s still there and just a bit of cable splicing will yield a very clear signal. The image above shows the camera in the middle, connecting via the spliced cable to an FPV transmitter on the right. This will all be strapped to the quadcopter, with the signal picked up by the receiver on the left and piped to a goggle display worn by the pilot. You can see the cable being construction process in the clip after the break.

If you’re looking for other cool stuff to do with your GoPro camera check out the bullet-time work [Caleb] did with ours.

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Geiger Counter Tells You If Your Dishes Are Radioactive

May 13, 2013 by Mike Szczys 47 Comments

geiger-counter-build

[Henrik] really turned out a nice little Geiger counter board based on a cold war era Geiger tube.

It works in much the same way as other projects along the same lines. It does run on batteries if needed, which is no small feat since the tube wants high voltage to operate correctly. And the video after the break shows it spitting out readings to a terminal window when connected to a computer via USB.

But what really caught our eye is the radioactive source material he used for testing. Since he didn’t have anything on hand he had to order something, and ended up going with a couple shards from a dinner plate. A radioactive dinner plate to exact and it’s a brand name you’ve probably heard of before. Red Fiesta Ware apparently used to be radioactive. It’s even mentioned in the intro to the Wikipedia article. Go figure!

One other thing we noticed was [Henrik’s] method of interfacing his multimeter with a breadboard. One of the project photos shows the probe with thin wire wrapped around the tip. We assume this is to make it easy to plug into the breadboard.

Despite this little digression away from the main project we did really enjoy learning about his build. And you can see him showing it off in the clip after the break.

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Clean And Minimal Self-balancing Robot

May 13, 2013 by Mike Szczys 6 Comments

The VertiBOT is a self balancing robot project taken on for the purpose of exploring how the sensors work in conjunction with some PID algorithms.

[Miguel] didn’t roll any extras into the build. But you have to admit that makes it look interesting. There’s almost nothing to it and yet, as you can see in the clip after the break, he accomplished everything he set out to.

The body and wheels are 3D printed, with black bands for tires to help give it some traction. Note the connection in the center of the body which allowed him to make a longer part by printing in two stages. On the electronic side of things he’s using an Arduino Nano. A level converter lets it communicate with the 6 DOF IMU board which is used to detect movement. Three potentiometers provide a way for him to tweak the PID loop without having to bother with reflashing any code. And of course there’s an option to control it remotely thanks to a Bluetooth module also in the mix.

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Hackaday Links: Sunday, May 12th, 2013

May 12, 2013 by Mike Szczys 23 Comments

[Johnathan Crawford] isn’t bashful about tearing the insides of his truck apart. He’s built his own remote starter using a Raspberry Pi.

We vaguely remember hearing about a startup that planned to deliver tacos using quadcopters instead of people. We assume that company was a bust but here’s the concept in action at the 2013 RoboGames [thanks Don].

On the topic of food: pizza and joysticks… do they go together? Perhaps. Here’s a joystick made out of an empty pizza box (note the remains of grease stains inside).

[Jonathan] brings to our attention the problem of running out of fingers to press all the buttons on your Monome at just the right moment. No worries, just add some solenoids to act as extra fingers.

Apparently some Samsung cameras (NX20, NX210 and NX1000) can use their USB port as a shutter release. The trick is finding the right resistor values for the ID pin [thanks Janne].

Plagued with a tablet dock that wasn’t weighty enough to prevent the device from tipping over [John] filled base with lead to keep the thing upright.

[Helmut’s] bathroom had no windows. He faked one using an Arduino and an RGB led.

And finally, as a reward for all the readers that made it to the bottom of the article, here’s a gem of a project. [Charlie] was inspired by the recent logic combo lock post to send in his own plans for a lock he made years ago. Unfortunately he can’t find the pictures from the build but the theory behind it is quite engaging.