NOW SUPER SIMPLE TO REPROGRAM!
Easy FTDI USB interface hardware explained in step 10
Easy FTDI USB interface programming explained in step 13
NEW code uploaded works perfectly with speaker output! see step 13
For those not familiar with geocaching, it is a wonderful treasure hunt/ adventure game for grownups and kids! Traditionally one finds a set of coordinates and cryptic clues on a website that hosts geocache locations. Using a hand held GPS device, one simply tromps off into the wilderness (or busy city intersection) and uses the power of observation and clue solving to find a hidden box usually with a prize inside! This is loads of fun and free! http://www.geocaching.com/
The Traveling Geocache still requires the user to get to a specific set of GPS coordinates but the hand held device is replaced by the Traveling Geocache itself. It is a locked box with an LCD display and one button. Upon pressing the button an intro screen welcomes the user to the Traveling Geocache and then displays the distance in kilometers from the target location. If the distance is larger than the programmed margin of error radius, the LCD informs you that access is denied. The box will not unlock until it is brought to the correct location! This is a great way to give a present to a friend or loved one. You can put tickets inside and set the magic location to the museum, aquarium, stadium, train station (DO NOT set a location that requires plane travel! Unopenable homemade electronic boxes are not welcome at airport security!). Any prize will do. Because the box is intended for a specific person, the prize can be far more special than in a traditional geocache.
Apart from the prize, the box also contains a log book where recipients can sign their names and write messages. There is also a usb drive with information on all of the electronics and software. This enables the recipient to reprogram the box, change the destination, customize the LCD messages, replace the prize, and re-gift the box to another friend, loved one, or trustworthy stranger. You can even leave a url somewhere inside the box where users can enter their names and destination locations enabling every user to track the life of the box!
This was my first time using GPS and LCD modules as well as my first time working with relays. Don't worry about the learning curve if you can already make a light blink on the arduino.
Thanks to sparkfun and instructables for holding the microcontroller contest. It really motivated me to document and post my first ever instructable! If you like it, please rate and vote for this project!
Please leave comments! =)