Reverse Geocache Based On STM32 And GPS Wristwatch

December 19, 2012 by 3 Comments

reverse_geocache

[Renaud Schleck] somehow got lucky enough to find a GPS wristwatch in the trash. It had a broken LCD screen so its wouldn’t be of much use on that next hiking trip, but he knew it still had potential. He used the GPS module and a few other parts to build this reverse geocache box.

Reverse geocache is a container that is locked, opening only in a pre-defined geographic location. We’ve seen plenty of these projects around here, like this one that talks, or this one which was given as a Christmas gift. They’re popular projects both because of the unique method of getting at the prize inside, and because it doesn’t take a whole lot of hardware to build one. Once [Renaud] had the GPS module he simply need a user interface, locking mechanism, and a microcontroller to pull it all together.

The interface uses a screen from an old cellphone and one push button. The latching system is a tiny geared motor salvaged from a Laptop optical drive. These, along with the GPS watch board are all monitored by the STM32 microcontroller which he programmed using OpenOCD and the Bus Pirate.

[via Reddit]

Stellaris Launchpad And Booster Packs Used As Frequency Analyzer

December 19, 2012 by 13 Comments

stellaris-frequency-analyzer-using-booster-packs

[Jordan Wills] got tired of being limited to eight pixels of resolution and having jumper wires littering his work space. He set out to upgrade his Stellaris Launchpad frequency analyzer project using booster packs. You may remember the initial iteration of the project which used an 8×8 LED matrix to map audio spectrum. With this upgrade he’s really putting the power of that ARM chip to use.

His first improvement with this project was to spin his own audio input board. It has a standard headphone jack for input and a few passive components to shift the signals to rest nicely within the ADC measurement range. The shield has two double pin headers and a group of four stand offs to serve as legs. This way it plugs into the female headers on the bottom of the Launchpad and provides a stable base for the assembly.

The second portion of the setup is an LCD booster pack for the hardware. Kentec manufactures this 3.5″ 320×240 LCD (EB-LM4F120-L35) complete with a resistive overlay making it touch sensitive. The increase in resolution, and availability of different colors gave [Jordan] plenty to work on. Since this add-on is designed for the Launchpad and has a driver library already available he was able to focus on adapting the FFT output for display and adding in new features. Don’t miss seeing what he’s accomplished in the clip after the break.

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O Christmas Tree Of Digital Logic

December 19, 2012 by 9 Comments

tree

[Chris] over at PyroElectro is getting into the swing of the holidays with a LED Christmas tree build. Unlike the other electrical Christmas trees we’ve seen this holiday season, [Chris] designed his tree entirely with digital logic – no microcontrollers included.

The tree [Chris] constructed on a piece of perf board is a beautiful spiral arrangement of 64 green LEDs.While we’re sure getting all the LEDs soldered to the right height, [Chris] makes it look so easy to create 3D structures with circuits.

The LEDs are driven with a set of eight shift registers, themselves clocked by either a predictable 555 timer chip or a pseudo-random pattern generated with a circuit built from a few hex inverters. By setting the tree to the sequential mode, a pair of lights travel slowly down the spiral of the Christmas tree. If set to random mode, an random number of LEDs light up and walk down the array of LEDs.

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Man Proposes To Girlfriend With An Arc Reactor

December 19, 2012 by 18 Comments

arc

Thinking long and hard about how to propose to his girlfriend, [Ed] hit upon a great idea: use an arc reactor as the ring box, with enough LED lights to outshine all but their love, and servos to present the ring and tug at the heartstrings.

[Ed] set about giving his now-fiancé from his arc reactor heart by building a simple circular arrangement of adafruit RGB LED strip and an Arduino. There are two modes for this arc reactor: a light up mode that simply looks awesome, and a ‘ring mode’ that uses two servos to open the front cover and bring the engagement ring into view.

After [Ed]’s fiancé said yes, the cover in the center of the arc reactor closes for its continued use as a desk ornament. You can check out [Ed]’s proposal contraption in action after the break.

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Building Pong For An 8-pin Micro

December 19, 2012 by 10 Comments

pong

For playing around with video signals and trying to create a an interesting microcontroller project, you can’t do better than the classic Pong. We’ve seen our share of microcontroller-based pong builds, but rarely have we seen an 8-pin microcontroller recreate every part of the first video game.

[Tim] started his PIC12F1840-based Pong build with just a few buttons for controls and a video output. This in itself is somewhat of an achievement, as [Tim] used all the data memory and every GPIO pin on this small microcontroller.

He had time to optimize his build and ended up adding the bleeps and bloops of the original Pong to his build. He’s got an interesting design on his hands, and also what is probably the smallest Pong clone in existence.

Manuel The Scottish Moose Speaks Your Tweets

December 19, 2012 by 10 Comments

tod1

The folks over at Torchbox needed a Christmas card this year. Previously, the most poplar holiday card was a web page that gave their visitors a chance to activate a ‘snow machine’ and spray confetti on a random employee, all while being streamed online. They wanted to replicate this bridge between virtual and real life interactions this year, and Manuel the talking moose was born.

Manuel needed a personality and interaction from random people on the Internet so the Torchbox team decided to make the fake moose head speak tweets in real-time with the help of a Raspberry Pi. The code running on the Raspi gets tweets with a #tbxmoose hashtag, sends that through a node.js script, and finally sent to the Festival speech synthesis system.

A few modifications needed to be done to Manuel before he was presented to the Internet. His jaw was chopped in half and a servo and animatronic controller were added for a proper presentation on Torchbox’s stream of Manuel’s random musings.

Heavy Metal Computer Case Desk

December 18, 2012 by 40 Comments

heavy-metal-computer-case-desk

This desk is also a computer case. From this view it may not seem like much, but the build log has hundreds of images which could be called metal fabrication porn. The desk surface is made of wood, but all of the other parts were crafted from stainless steel.

The three components that weren’t fabricated by [Paslis] are the pair of legs and the column supporting the screens. These pieces are actually lifting columns that allow you to adjust desk and screen height at the touch of a button. The build starts off with a sub-surface to house the computer guts. After careful cutting, bending, welding, and polishing this comes out looking like the work surface in a commercial kitchen. After attaching the lifting legs to that assembly a foot for the desk takes shape from square pipe which is then skinned with stainless steel to match the finished look of the sub-surface. After spending countless hours on brackets, trim pieces, grills, and wood accents he sent everything off for painting before the final assembly.

Certainly this is in a different realm than the case desk from yesterday. But a mere mortal can pull that off while this is surely the work of an experienced tradesman.

[Thanks Andreas]