A reverse geocache – a box that only opens in a specific geographical area – is a perennial favorite here at Hackaday. We see a ton of different implementations, but most of the time, the builds are reasonably similar. Of course dedicating a GPS receiver solely to a reverse geocache isn’t an inexpensive prospect, so [Eric] came up with a better solution. He’s using a smart phone as the brains of his geocache, allowing him to keep the GPS and display outside the locked box.
The build began by finding an old box and modifying it so it can be locked with a servo. The only other bits of electronics inside the box are an IOIO board, a battery pack, and an I2C EEPROM for storing a few settings. On the phone side of things, [Eric] wrote an Android app to serve as both the programming interface, UI, and GPS hardware for his reverse geocache. It’s exactly like all the other reverse geocaches we’ve seen, only this time the controls are wireless.
[Eric] put up a video demoing his reverse geocache. You can check that out after the break.
Continue reading “Putting the brains of a reverse geocache on the outside”
[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.
Here’s a talking reverse geocache puzzle box which [Erv Plecter] built as a wedding gift for his friends. The box itself isn’t really the gift, but a surprise delivery system for a collection of cash from the couple’s circle of friends to go toward the honeymoon. We think this is about fifty times more fun that getting a fat envelope of bills. Who would really expect to find cash inside once you finally get to the target location?
Unlike the other geocache box we saw recently, this one has no display to show you clues to the destination. Instead, it plays back audio clips which [Erv] recorded himself. They’re quite tongue-in-cheek which is another nice personal touch. The pin seen protruding out of the right side of the box can be removed to play a clue and check the location. It’s connected by a little chain to a 5 euro-cent piece which conceals an emergency release mechanism for the lid. The device is powered with a Lithium battery and can be recharged without opening the box via a USB port in the side.
We’ve embedded the video demonstration of the box after the break.
Continue reading “A talking reverse geocache puzzle box”
[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.
Continue reading “Reverse Geocache box looks great and packed with features”