Geocaching on Anzac Day 2014

Did a few geocaches today, and revisited an old favorite so that Jana could do it.

Bed Bugs is a classic!!

We brought our own batteries as suggested by the cache information.

...and at a different cache, here's a really nice custom-carve-out hiding place. :)

More "favorites" geocaches.

Did a couple really nice geocaches today. One being another of Muzza's electronic game geocaches. Well worth it. Check these out when you get a chance:

http://www.geocaching.com/geocache/GC4062J_national-treasure http://www.geocaching.com/geocache/GC2HWVE_who-wants-to-be-a-millionaire-v-2

~5v USB Battery Pack

My mobile phone can't go geocaching with the display-on and locating for more than about an hour before running the battery low. The phone battery is an impressive 3.6V with 1600mAh capacity, though clearly not enough for extended use. I needed a geo-battery-pack.

So I made this. It's a 4.8V, 2600mAH cell made from old cordless drill batteries.

Construction images below:

An old cordless drill battery pack disassembled with the dud "sub-C" cells removed.
Each cell is 1.2V, 1300mAh. I wired up x2 banks of 4 cells, creating a 4.8 volt, 2600 mAH battery bank.
Sizing up a block to mount them in. I carelessly oriented the grain 90 degrees in the wrong direction. Notice the end-caps have grain across their width, not their length. These are ULTRA flimsy, hence the bazillion screws holding them on in the final-block.

Trial fit. Space not yet hogged out for the plugs.


Trial fit with the USB plugs in place.

Filing out the USB plug gaps in the caps.

Magnet Phone

I wanted to attach my phone/GPS to the bike without the headache of a proper bracket. I'd tried a few magnetic gizmos in the past that I'd made with those flexible flat fridge magnets, but wasn't happy with their strength, or scratching, or they were just too poxy to use. But today I remembered I had a pile of very slim rare earth magnets from a series of Hard Drives that I'd pulled apart in the past.


So whack a pair of these inside the gel-case of my phone...and you can see where this is going. No adhesive necessary.


So easy. Can't believe I didn't think of this before.





Went to a mates house the other day with this setup and it worked fine. The phone didn't bounce, shift, move, anything. GPS worked fine.

I had small concerns about magnetic interference but the more I thought about it the more I realised that a static field wont effect the functionality this phone uses, both for 3G nor satellite location. If there were a pulsing electromagnetic field going on in very close proximity, then it would certainly have troubles. Even then, it may only be at certain harmonic frequencies that could cause problems, or of a strength high enough to actually cause current flow problems in the phone circuitry itself. Not something these magnets are going to achieve.

As it is, I'm very happy with it. Super simple, super easy to use, completely non invasive. Pure win!!

Extra Power

I bought a mobile GPS for the motorcycle a year or 2 back, and really haven't used it since I got my new(er) phone which has a better embedded gps. This portable unit is waterproof, and transmits driver instructions on the FM band. There was a small receiver which you'd mount to your helmet etc. Overall it was a great unit, except the battery was complete rubbish, with virtually zero lifespan. It just wasn't functional without supplied power from the mount-bracket which was wired to the bike battery.

So I decided to add my own power source so the kids could use it when we go geocaching.


So many screws between me and getting this thing apart. It was built like a brick with nice solid rubber bushings for every component, and metal brackets compressing everything together.


Finally cracked it open. (this is an out of sequence photo, but you get the idea)


COMPLETE RUBBISH BATTERY!! 1000 milli Amp Hours. That's functional for MINUTES, maybe an hour when running a backlit LCD and Windows CE with the GPS application and receiver running. The spec is fine if the unit is idle...but worthless when in use while portable.


So I made my own battery pack. I couldn't find a triple-AA pack at Jaycar, so grabbed 3x1's and stuck them together with hot-glue on a small aluminium plate I cut out of an old computer CD enclosure. ;-)


Hot glued the battery pack assembly to the back 1/2 of the GPS unit.


...and fed the wires through a small hole I drilled through earlier. I then re-soldered and heat-shrunk the original battery plug


At this point the very straight forward job was done. Put it all back together and VIOLA, 7500mAh battery pack (standard rechargeable batteries are 2500mAh/ea), and go have some fun with the kids.

However...during the process I either nicked, pinched, shorted-out, or otherwise destroyed the LCD screen. I was certain the unit was "booting" because I saw it flicker once, and small debugging LCD's on the PCB indicated it was working in its on/off/sleep states. I was VERY VERY angry at myself. This was a really straight forward job. Simple in every possible way. I was having a rare moment of actual...happiness...listening to music as I did this. Then **BLAM** you broke your $200 toy. Idiot.

So I'm pretty angry now. I walk up and down the hallway eating cookies by the hand full, then order a pizza to drown my sorrows in its pure awesomeness. /dramatic-effect.

I figure there's no way I can reasonably expect to replace the LCD. During a post-op inspection, I actually make things WORSE by shattering the glass screen that the touch-digitiser is adhered to (this is a second component, not the LCD itself)

Wow...I'm on fire.

In a fit of desperation I get the magnifier on the part/s, and write down their bazzilion-digit part numbers and try to find them online. I was really surprised to find them indexed on Google at all. Even better, a few places were selling them wholesale to importers from China, but only in orders of 5 or more. As I dig some more, it turns out the parts used in this GPS are actually really common Gizmologist project components, but I still can't find a source for single units.

Ebay? Wow some dude is selling them!!...from China. I ask him if he's selling the touch-screen as well. But replies he doesn't. Oddly, I find another seller with the touch-screen...but he doesn't have the LCD. So I order both (cost me ~$40 total) and put the whole project on hold for 10 days while I wait for shipping from both guys.

And they arrive on the same day!! In the same boxes...with the same labels. And the same return address? I guess they were both drop-shipping. Oh well, can't really complain, I got the parts!!!


I plug in the new parts, and I see light :-D Very very happy now. So glad I didn't destroy the little computer unit. Running on USB power at this point.


MY first test with the new battery pack as source power. Works fine, as it should ;-)


The unit doesn't have a speaker, but as mentioned earlier it does transmit audio via FM. There is actually a little speaker-out port on the PCB, so I decided to test it out. Unfortunately I didn't really have any lower-power piezo speakers to test it with, nor an oscilloscope to properly test the port. So I gave up on that (for now).

In this picture you can clearly see the speaker port just down-right from the battery-port. Same style plug. The FM antennae can be seen top left near the black alligator clip, connected by a short piece of grey wire. The SD card is standard SD, not micro/mini.

I'm just simply amased that in this day and age it's cheaper to produce this kind of product with an off-the-shelf mobile computer PCB, with shelf display parts, to run an essentially dedicated GPS unit as an application within Windows CE, rather than as a static firmware circuit. All for $200 bucks at a grocery chain!! (Aldi) I've played around with WinCE on this unit when I originally got it. I'm boggled by how powerful this 7yr old operating system is, and I still wonder how Apple is in 2011 able to get any market share with their i-products. I'm running a GPS "app" on this unit, I can web browse (albeit really hard with this actual unit due to limited input plugs...not part of its sale-design), watch videos, slide-show photos, listen to music etc from this 2004 operating system. The original iPhone was a 2007 release and "swept the world" with what was really just "off the shelf technology". Try and keep up guys ;-)

So anyway. Basic job complete. This puppy has "UNLIMITED POWA' " for the kids now :-D

My first "favorite" Geo Cache

On the geocaching.com site, you can "favorite" one cache, for every 10 that you find. I certainly found my first favorite today. This was a 1.5(easy to find) / 1.5 (easy terrain) cache. But it's the clever ones that you'll always remember.


Errmm...that's a sprinkler right?


"This sausage looks very suspicious !!" I actually did this one on my round today, hence the glove. Yes I was geocaching "on the job". What a life. This was the SECOND time I came back here today. I couldn't find it the first. Rode off...had a think about it, and came back later. Couldn't let that little sucker beat me ;-)


"Official Geocache" I've edited the location label out.


At first I thought this might have been a pre-fab "to look like a sprinkler" cache, but these look like standard parts from Bunnings. The finders-log is rolled around a piece of coat hanger for easy handling. Another homage to the pure awesome of real wire coat hangers.

So in summary: Geocaching is really fun. Mildly addictive. Offers micro rewards. Had a range of difficulty settings. It includes all the elements of a great online game, 'cept you're getting your vitamin D and exercise out in the sun!! Git ooot' thar 'n have ye sum fun!! ;-)

My 1st GeoCache

I FINALLY went and did my first GeoCache. Given that I'd consider myself a bit of a techno-monkey and gizmologist, it's a little embarrassing that I'm so slow to the party. I've even had a GPS for a couple years now, and more recently on my phone.

There are LOADS of geocache listing sites on the net. I had a bit of a dig around, and it seems that geocaching.com is undoubtedly the largest site, with a number of GPS and phoneGPS apps that run with accounts linked to that site. It made sense to start there.

So I went and grabbed the phone app for my phone. You can use GroundSpeak, or Trimble's GeoCache Navigator. (there are others, the geocaching.com API is public) I'm on a Symbian phone so went with GeoCache Navigator. These apps actually tie in to your geocaching.com account. Very cool, but YOU DON'T NEED THESE APPS. You could just get the GPS locations from any site, and then go find the cache with whatever GPS you use. The apps are just cool tie-ins so you can use less of your brain getting (auto-send coords to your phone), and finding the caches (follow the arrow!!) :-D

So, from geocaching.com I did a search for close cache locations, and decided to go find a traditional one classed as 'easy' about 300 meters from my house!! You can scroll down the page on that link and see my log entry as "Mashee". :)

***Spoilers for this cache below. Unlikely that anyone I know will do this one anyhow****

The "clue" said look up, so I figure it's up in those trees somewhere.


Hmm, nope, this location is closer, and seems a more logical public spot. Etiquette dictates you scurry around for your cache covertly, not revealing its location to non-participants. A quick look around, and all is clear. Nobody around. Lets see if I can find this thing!! Looking up...yup, I can see something up in the framework!!


Got it!! This was very cool. Great choice of container, and a list of previous cachers have signed in. I entered my "FIRST ENTRY!!" notation, folded the log back into the mint container, and put it back where I found it :)

This was truckloads of fun. Doing this with a friend, or group would be awesome. You could easily make a great day out of this. I'm off to log a pile of these into the phone so I can pick a few more off as I drive around the local area when out shopping or coming home from work etc. Any kind of day-trip will prove extra fun with a few of these logged to find. The kids will go nuts doing this too. Can't wait!!!

notes: I've posted a pic of the actual location and container for this cache location here on my blog, but as a general rule you wouldn't do this on your geocaching.com account. Be discrete with images and keep it fun for other cachers etc.

additional notes: I bought Geocache Navigator from the nokia ovi store, not from the navigator site itself. I figured it would be easier to re-download the app in future from a site I've already got an account with. I'd suggest using your respective iPhone or Android store to do the same. This was a full-blown app that tied into geocaching.com's API, not simply a glorified HTML page, so I had no reservations about actually paying money for it. A rarity for "apps"

Some more pics from the following days.

Found my first trackable coin! Its travels are registered here. Found it at the Freeway Triple cache. Currently in my possession till I drop it in another cache.





Many, many trees. Most with great hiding spots. It was a total fluke I found this one.

Full Log!!