rudolphs

Thats awesome!

How about something like this, in a geocache box: .

Very nice!

Radio Shack makes a nice recording/playback circuit: here that comes with a connector for a 9V battery, and stores recordings even when the battery is removed.... surprisingly this is not the case with some other cheap recorders. Also, for any electronics in a cache: Attach a button/switch to the inside of the cache. Position it so that when the lid is closed, the button/switch is pressed. You can use this switch to cut the battery power to the electronics. This is tremendous for saving battery, and nearly foolproof.

Any chance you'd care to share your plans for that? I have a multi I've been working on and that would fit my theme perfectly! sorry for the late reply. I don't have a schematic, but this should get you on your way: Cheap Arduino

Yes, we were worried about this too. Hopefully the clear geocache markings will help identify it.

And so, back to our topic... Not your standard lock-n-lock: There are three pushbuttons on the right half of the circuit board. The finder enters a 6-digit code using these buttons. If the code is correct, the LED display shows the coordinates to the next stage. There is a switch glued to the edge of the lock-n-lock, that cuts power when the box is shut. This gives the stage a very long lifetime before you need to replace the battery. For more details:

We have done this for a stage in a night cache. Tried replacing the standard LED in one of those lights with an infra-red LED. Cameras can pick it up a little. It works much better if the Infra-red LED is pointed at the cacher/camera. Can work as a beacon 100+ feet away at night! More Info: http://forums.Groundspeak.com/GC/index.php...t&p=4014649

In our experience, it is usually best to put them on the inside of the container. The nightmare with rare earth magnets though, is that if you have more than one, they all stick together when the glue is drying and it comes out a mess. Maybe welding gets around this.

Well, the inside looks like a birds nest with all the wires, so here is a fairly clear schematic of sorts: Assume that any two wires that cross on the schematic are not acutally connected, unless they cross at the terminal of another part. Hope that helps. The gray switch on the side of the CD mechanism is open (off) when the CD is in, and closed (on) at all other times. If you look carefully, many CD players have a switch like this already inside. Good luck! Incredible! Does this use a magnetic switch of the burglar-alarm type, or a homemade verison? Very cool!

Either the cacher has to bring a CD player, or they can go to an an additional set of coords to use a Walkman that is installed in a tree and running off a solar pannel. Whats the fun in that? If you can make it unnecessarily cooler, then by all means do so! We have a whole nightime multi based on electronic mechanisms and such. I found a cheap and hackable little solar walkway light ($3) at Target. It returns a voltage of 1.5 V, which is the same as a normal AA, AAA, C, or D battery. This makes it perfect for powering small devices. You could power an Arduino (used in the project at that link) or related microcontroller off of three or four of these lights.

Completed container ready to go into the field: When opened, a CD is ejected by spinning rubber rollers. The CD has a recording of the coords to the next stage. When done listening to the CD, the cacher flips a switch, which reverses the rollers, and allows the CD to be put pack. A limit switch at the top edge cuts the power when the ammo box is closed, therefore giving the battery a long lifetime in the field. We hope to avoid a bomb scare by clearly marking the container as a geocache.

Neat hide. Watch out though, those sqirrels might geostash it! EDIT: From our modest experience, a 3 sounds about right.

Of course, the instructables way may be more durable in the long run, as is the case with most cost/functionality trade-offs.

Could you please provide a link to the instructions? FOUND IT !!!Thanks care to share than? Here it is on Instructables but I think I like this one better as a potential geocache: Thanx for that friend of Chad. I just spent half an hour looking at verious designs of that and now I need to build one. Don't build just one if you somehow intend to use it as a cache container. Build two or three, and place it close to home where you can easily and quickly do the neccessary maintenance. Take it from someone who has placed other high-maintenance caches in the past. No, not for a cache container.. just for fun. It is actually half done now. My extreme collection of old RC parts has made it a little easier for me then it may for some. (extreme collection is due to crashing many RC planes and a few choppers... plus a few old RC car stuff) It was my former addiction before I discovered geocaching. This is cheaper. This seems like a cool idea for a cache I wanted to point out that there is another way to do this circuitry, that is much simpler (and cheaper if you have to buy the parts) than the instuctables link. A simple SPST (on/off) switch is used. When a person flips the switch, power is given to the arm motor, which comes out and flips the switch back off, and therefore cuts its own power. A rubber band or spring returns the arm back to its original position. This eliminates the need for the more complex circuts and additional switches.

Thanks, these are great directions!

That actually rather bothered me, too, to be honest. The overload of words to describe the stupidity of this damage is overwhelming. All to (ahem) "challenge" some geeks with a GPS? I'm sure the Geocaching gawds are cringing with this cache. Don't worry, these trees had already been chopped down by a lumber company and then abandoned because they were not thick enough (this was pretty sad, because a whole section of woods was wasted). The one with the bolts in it was cut but fell into the crotch of another tree so that it was leaning. Sorry for not clarifying earlier.

GC206G2 (BuckResv - Nightscape): New nighttime multi-cache of ours. At the first stage you park at the parking area and listen to a recording on a certain radio frequency through your car radio. After that, it incorporates solar powered devices, radio control, reflector trails, light sensors, hidden speakers, combination locks, signal lights, and the final has a surprise in it triggered by opening the box.

We have a multicache with a few interesting containers... 1. A hole drilled in a tree, with the bark used to make a plug for the hole with cache inside. It is nearly invisible, even from 3 feet away, even when you know exactly what you are looking for. 2. A huge machine bolt (5" long, 1" thick) that was screwed all of the way into a tree, above head hight. You had to get the right sized wrench, unscrew it for about 20 minutes, retrieve the micro from inside the bolt, and then put it all back, including screwing it all of the way back in. The challenging part was that there were several of these bolts in the tree (each required a different wrench), and only one had the cache in it. Naturally, cachers started with the lowest bolt because it was easiest to reach, and it just so happened that the one with the cache in it was the highest. The average completion time for this multi, including all 6 stages, was about 9 hours.

Thanks everyone for the ideas. I have combined a few ideas and come up with two reliable, low-cost, electronic geocache gizmos. One cache involves the infrared LED that was mentioned earlier. Take a cheap solar-powered walkway light ($3, available at Target), and remove the LED. Then solder two wires onto the contacts where the LED was, effectively making a 1.5 volt power source. Then take an infra red LED ($4, Radio Shack) and solder this to the ends of these wires. Next, you need a reflector. I used one from a broken flashlight, but one can be made easily from aluminum foil. Position it around the infra-red LED. Finally, to water-proof the whole thing, glue it into an upside-down glass jar with the solar panel up at the top (the base of the jar). The LED and reflector are glued against a side pointing out. Then, put the lid on tightly and duct-tape it shut. End result: an infra-red beacon that charges during the day and glows all night. Because it is infra-red, you can only see it through night-vision goggles, or through the screen on a digital camera or camcorder. It shows up as a glowing white orb, and can be seen (through the camera screen) from over 70 feet away, without zoom. Total cost: $7 to $8. Time: 45 minutes. The second cache is a little more expensive to build, but makes up for that in coolness. The first step requires a cheap 2-way radio or walkie-talkie ($15 for a pair, Radio Shack). Unscrew the casing and locate the two wires that go to the speaker. Clip these wires and solder on a pair of longer wires. To the ends of these wires, solder an LED or two or three ($0.40 each, Radio Shack), or even an infra-red LED (explained above). Or, you can wait until you have removed the LEDs in the lamps, then use these, which happens in the next paragraph. Now, turn on the radio and turn the volume up all the way. Using your other radio, talk or press call. When you are transmitting noise, the LED should light up. The next part uses more solar pannels. The reason for this is that your batteries in the radio will only last a few days. Of course, you could go to the cache and change the batteries every three days, but that has no finesse. So instead, you can hack solar-powered walkway lights ($3 each, Target). Use one light for each battery in the radio. Remove the LED from each one. Then solder two wires onto the contacts where the LED was. When you have done this for all lights, wire them in series. (positive wire on #1 to negative wire on #2, positive wire on #2 to negative wire on #3, etc.) Remove the batteries from the radio. Now, you will make your radio solar-powered. Open up the casing of the radio again, and locate the two wires going to the battery compartment. Clip them off and solder the loose solar panel wires to these wires. Make sure you solder the positive to positive and negative to negative. Now you are finished. Turn the radio on, then waterproof this cache by putting it into a lock-n-lock or clear Tupperware container, or a glass jar if it will fit. Tape all seals shut, and make sure the solar pannels are facing up. End result: When a cacher broadcasts on a specified channel, the LEDs will light up. And, best of all, this will charge every day and should run for a few hours every night after sundown. No batteries required. Total cost: about $30. Time: 90 minutes. Enjoy these small projects, and feel free to use them in your own geocaches. Thanks to everyone for the fantastic ideas. ~The Rudolphs