Reverse Geocache Box Looks Great And Packed With Features

January 19, 2012 by Mike Szczys 8 Comments

[Ranger Bob] crafted this great looking Reverse Geocache box. Our favorite feature is the black piece of acrylic on top. It’s laser cut (not sure if the letters are engraved or not) and gives a great finished look while hiding a couple of things at the same time.

The orange box is a metal cash box, and there’s a smooth indentation in the lid where the handle resides when not being carried. [Bob] removed the handle and mounted the GPS module in that void. But there’s also an OLED display mounted next to it. As you can see in the demo video after the break, the screen is bright enough to be seen clearly through the smoky acrylic covering that depression.

This project gave [Bob] the chance to order his first professionally made circuit board. He did the design in Eagle, managing to keep within the 5cmx5cm limits of Seeed Studio’s least expensive Fusion PCB option. The board hosts the PIC 18F87J50 responsible for handing the screen, GPS module, input button, and USB port. Power comes from an internal Lithium battery.

We’ve featured a lot of Reverse Geocache boxes and they’re still one of our favorite projects because so much love goes into the design and build process. Here’s another one that we chose randomly for your amusement.

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See Where Socks Has Been Using A GPS Tracking Collar

October 11, 2011 by Mike Szczys 32 Comments

[Buxtronix] wanted to know where his cat (named Ash, but we thought Socks sounded much more cliché) was going when on the loose. He designed a GPS tracking collar and a way to map the data it collects.

The hardware actually turns out to be very simple. He needed a GPS module to gather location data, and a way to store that information having decided that live broadcast was not feasible. He hit SparkFun because they have a GPS module that is small enough for a cat collar, and outputs data with one serial pin. Unfortunately this module is no longer available, but if you have a similarly sized replacement let us know in the comments. Data capture is made easy by this device, you just need to record the serial data as it comes down the pipeline. [Buxtronix] used an OpenLog board as it dumps the data onto an SD card. When [Ash] returns from his roaming, [Buxtronix] grabs the SD card, and uses a Python script to convert the NMEA data to KML format which can be overlaid on Google Earth and Google Maps.

Make Your Own GPS Receiver!

October 1, 2011 by Jeremy Cook 40 Comments

GPS receivers may be available for well under $100 these days, but what’s the fun in buying one when you can build it yourself? According to [Andrew], the creator of this device, he was inspired by Matjaž Vidmar who developed a GPS receiver from scratch over 20 years ago. His article can be found here and includes some nicely hand-drawn diagrams as well as a lot of theory.

However, [Andrew’s] article is a bit more up-to-date and features plenty of theory itself. He explains how he built his four-channel GPS receiver, able to track four satellites at the same time. This is the minimum number of satellites needed to track your position using such a device.

GPS technology is quite incredible, and the amount of soldering as well as the understanding of the theory behind it required to build such a device is astonishing. Interestingly (sadly?), it seems we are beyond the time of LORAN hacks, but if you have an old one to share, be sure to send it in! For something a bit easier, maybe one could try making a GPS “cateye” to track what your pet does all day!

JGPX Keeps The Bachelor Party Moving In The Right Direction, Regardless Of BAC

September 16, 2011 by Mike Nathan 6 Comments

jGPX_bachelor_party_navigator

[Davy] and his friend [Chris] were tasked with putting together a bachelor party for their friend [J], and had a little more in mind than the standard drunken revelry. To earn the privilege of partying his brains out, they decided that [J] would have to fulfill a series of tasks and challenges before joining up with the rest of his friends for the evening’s events. [Davy] didn’t specify what these tasks were, lest he spoil the surprise, but he did let us in on a little device that he and [Chris] built to help guide the bachelor through his day.

They were a bit worried that the bachelor would get sidetracked during his journey if he happened to imbibe along the way, so they built a device called jGPX that would ensure [J] stayed on track and on time. jGPX is a custom GPS navigator consisting of an Arduino, a GPS module with built-in antenna, and a compass. The pair created a set of routes in Google Earth, exporting the data to KML for interpretation by their device. The jGPX is meant to guide [J] along via a small LCD screen that shows him the distance to his target as well as the proper direction of travel to get there.

It looks like [J’s] friends put a lot of effort into his party, and although there are no details as to how things went, we’re sure it was a blast!

GPS Audio Tour Brought To You By Surface Speakers

September 6, 2011 by Brian Benchoff 8 Comments

The team at Eschelle Inconnue wanted to “trace a sound cartography of Islam” in Marseilles, France, so they came up with a clever little GPS walking tour powered by an Arduino, MP3 playback module, and a surface transducer speaker.

The team used a Processing app to define geographic areas where each MP3 file would play. An Arduino on the build queries a GPS module and selects the audio file from an MP3 playback module. This isn’t uncommon, and a lot of large outdoor museums (think battlefields) have similar setups.

Determining which audio to play at what location is fairly easy, but that’s not what makes this build special. Instead of simply hooking up a pair of headphones to the build, the team decided to use a surface speaker that turns just about any solid material into a speaker. From the writeup, this is supposed to, “diffuse sounds by giving the illusion to collect them, to listen to the words of the walls, the whisperings through the materials” but we think it’s just a great way to have several people listen to the same audio file at the same time.

Czech-ing Out The View From 31 Kilometers

September 5, 2011 by Brian Benchoff 19 Comments

The team at czANZO, the Czech Amateur Near-Space Object group, sent up one of the best high-altitude balloons we’ve ever seen last weekend and the resulting video is remarkable.

The team’s build blog (Google Translate link for everyone without Chrome) goes through the design and construction of their payload. Like every other balloon build we’ve seen, a styrofoam cooler is used for the enclosure, but there’s a lot of really neat additions that make this build special.

The team included a cut down device in the event the balloon gets caught in the jet stream. Without this cut-down device the balloon could end up hundreds of miles away from the launch point. That’s the reason for the cut-down device they’ve given, although we suspect it’s an excuse to play around with pyrotechnic rope cutting. The optical and audible alarm is something we haven’t seen on many high-altitude balloon launches, which is odd because it made ground recovery much easier.

The team has a lot of video from the flight that [Pavel Richter] dumped onto Vimeo. We really like the footage showing all of Prague, you can check that out after the break.

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Engine Hacks: A Pulse Jet UAV By Any Other Name Would Still Be A Cruise Missile

September 5, 2011 by Brian Benchoff 33 Comments

Imagine our surprise when we learned [Bruce Simpson], who made headlines in 2003 with his $5000 DIY cruise missile, is still alive, not illegally interned in a black ops prison, and still doing what he does best: building really awesome remote-control airplanes.

The first ~~successful~~ mass-produced pulse jet aircraft was the German V-1 flying bomb. The V-1 had a very primitive guidance system, but the unmanned pulse jet aircraft quickly evolved into a few target drones used by the US Air Force. There was never any significant advancement towards improving the fuel consumption, noise level, or heat signature of pulse jets, so they were superseded by the superior turbojet. Despite their failings, pulse jets are remarkably easy to build and amazingly fast.

Instead of being antagonized by the New Zealand and United States governments, [Bruce] spends most of his time now working on pulse jet projects. He’s flown quite a few modified R/C planes and has an electronic Engine Control Unit for his jets. One of his most impressive projects is the 100 pound thrust pulse jet that was later attached to a go-kart. His no weld version of a pulse jet can be built in even the most minimalist work shop and is the epitome of an easy-to-build jet engine.

To get an idea of how fast [Bruce]’s planes can be, check out his Long-EZ R/C pulse jet in action after the break.

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