A Steampunk Combination Sketchbook

January 16, 2013 by 28 Comments

book

[Admiral Aaron Ravensdale], fine craftsman of steampunk wares, just finished up a new project. It’s a sketchbook protected by two layers of security, covered in gilded leather and drenched in the expositions of a [Jules Verne] novel.

The first layer of security for this sketchbook is a combination lock. On the cover are four switches, each with four positions. These are connected to a PICAXE microcontroller which goes to the next stage of the lock once the correct combination is entered.

The book’s security also includes a knock sensor. With a small piezo element hidden under the cover, [Ravensdale] deeds to tap the book with a specific pattern before it opens. The mechanical part is a small hobby servo also mounted to the cover that releases a pair of brass clasps once both locks are opened.

Like all of the [Admiral]’s builds, it’s a fine piece of craftsmanship, equally well suited to take on a holiday with the baron or to the opium dens of Ceylon.

You can check out [Admiral Ravensdale]’s demo of his sketchbook after the break.

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AM Chiptunes Played By A Modified Antenna Analyzer

October 26, 2012 by 5 Comments

Believe it or not, this VK5JST aerial analyzer kit is going to rickroll you. [Erich] wanted to see if he could use the device in a different way. His adventure led him to use it to feed different tones to an AM radio, producing the all too familiar [Rick Astley] offering.

There’s a fair bit of math that goes into getting the correct signals to generate a given pitch. But it basically boils down to patching into the hardware early in the RF generation. This way an audio signal can be rolled into the carrier frequency. Since this kit uses a PicAXE microcontroller with available source code it is rather easy to add audio input to tweak what the chip is putting out. But there is also some hardware tinkering to be done. Read more about that at the article linked above, and don’t forget to check out the bottom of that page to hear the final results.

μJ, A Java Virtual Machine For Microcontrollers

October 15, 2012 by 78 Comments

[Dimitri] sent in a project he’s been working on that implements a Java Virtual Machine purely in C, and is easily portable between microcontrollers such as the AVRs and PICs we normally see, ARM devices, and even the lowly 386.

Before going into the ‘how’, [Dimitri] first covers why he wanted to run Java bytecode on a microcontroller. Basically, he found existing solutions like the Arduino environment too complex for people just wanting to program a chip. Arduino and PICAXE require C-like syntax and pointers; not the easiest thing when everyone and their mother can program in Java.

As for how [Dimitri] managed to pack a JVM into a microcontroller, that’s another story entirely. Everything in the JVM, from double, long, and float data types to exceptions, neat thread-related functions such as ‘synchronize’ and even methods such as String.charAt() and String.length() are completely optional. If your microcontroller is too small, just disable the functions you don’t need.

As for how well – and how fast – μJ is able to run, [Dimitri] threw up a demo of an ATMega644 and PIC24 running his JVM and a small Java app. You can check those videos out after the break, or just download the source for μJ on [Dimitri]’s site.

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The Minotaur’s Revenge: Dueling Labyrinths

July 28, 2012 by 7 Comments

In case you hadn’t noticed, we participated in a contest recently. The RedBull Creation contest. The basic idea was that they gave us 72 hours to build something based on a theme. The whole thing would be streamed live as the 12 teams competed. The theme was “game of games” and the rules were pretty basic. It had to be a game with a clear winner (nothing too general), it had to be safe, and it had to fit in their shipping container.

Our project is called “the minotaur’s revenge”, and is basically a set of dueling labyrinths. A pair of giant tilting mazes that have to be controlled while attempting to trigger traps on your opponents table. We knew that watching us screw some wood together for 3 days would be painfully dull, so we put extra effort into keeping our feed amusing. We had scheduled events like a fire breather, grafitti artists, people in costume, and strange things happening all the time. We took time to answer questions and converse with our watchers. It paid off, our feed was usually host to double the viewers of any other feed.

Keep reading for a full writeup on how everything was made, along with a ton of pictures and some video.

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Cat Trainer Will Keep Them Off The Counters

July 12, 2012 by 18 Comments

Our cats are not allowed on the kitchen counters, and [Iron Jungle] has the same rule. But he spotted some foot prints on the hood above his range and the addition of a security camera caught this picture of [Kelso] breaking the rules. Since he’s not always around to make the fur-ball behave he built an electronic cat trainer to do it for him.

The functionality needed isn’t very intricate. You need to monitor when the cat is where it shouldn’t be and then chase it away. For the latter he grabbed an infrared range finder. When the cat passes in front of the sensor it will trigger the second part of the system: a high-pitched buzzer that’s extremely loud. Any microcontroller will have no trouble driving the system. In this case it’s a PICAXE 28X1.

You can see the trainer in action after the break. It definitely works, because just playing the video chased our own sleeping kitty out of the room.

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A Simple RF Signal Strength Meter

June 12, 2012 by 18 Comments

rf_metr_breadboard

[Scott] wrote in to us with his simple, but well done RF signal strength meter. As he points out in his post, sometimes an Arduino is overkill, so a Picaxe 08M was used instead. Apparently this was a refresh of a high school project that he did. Certainly many of us would have liked to go to that high school!

An interesting part of this project is how he used a laser cutter to produce his PCB traces. This was done by applying black paint to the copper on his board and cutting everywhere he didn’t want copper traces. The results were quite good, and should work well when this project is finalized in an enclosure

Check out the video after the break to see this circuit in action. He explains the build in it, but if you just want to see the signal strength lights come on, fast forward to around 2:25. Continue reading “A Simple RF Signal Strength Meter” →

Pingbot: Adorable And Fully Documented

June 10, 2012 by 24 Comments

After building many functional but somewhat unfinished looking bots, [Tomdf] really wanted to produce something that felt “complete”.  Pingbot is the result and here’s how [Tomdf] describes it:

Pingbot is a very small (38mm diameter), usb rechargeable, programmable, musical, remote control robot designed for maximum fun and danceability.

Though I wasn’t inclined to dance I did find myself smiling watching the video. Pingbot does look finished and has quite a bit of personality too. The brains inside the Pingbot are a Picaxe 08m2. With a 110mAh Li-Po battery, Pingbot can dance happily for a quite a while too. When juice is running low, just plug into your USB port for a recharge. You can find all the info and schematics on the instructible as well as the files to print your own Pingbot shell.

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