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Help with an electronic geocache project

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badscr

New Member
A big box with a spring loaded door that has a Door-Lock-Actuator tied into the µController.
This way people have a secure/Weather-resistant place to put there cache.



Off topic.
As for Trackable Items;
An electronic Travel Bug: with a built-in GPS data logger and a Camera $$$
 
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MrDEB

Well-Known Member
If you only have one digit on then flash for 10-15 seconds the correct cordinates, the battery should last a long time
 

vne147

Member
Hey folks, I really appreciate all the feedback.

I'm enjoying thinking about all the ideas offered. I don't think the solar option will work well, because as vne157 guessed, the container will be hidden and won't get much if any sunlight. I'm not really concerned about power capacity, because there will be lots of room available in the container and I'm happy just using a four pack of D cells for practically unlimited "on" time.

I am having to restrain myself from jumping on the more complex ideas because I don't want to frustrate people in the field. The point of the hobby is the hunt and if they are able to find the box, then I don't want them to be prevented from getting to the next stage because they can't figure out the settings. And sometimes they'll be standing in the rain, or it will be really hot, or they'll have small children with them, etc, so I want to make it more enjoyable/easy than satisfying-to-solve-but-hard. So it's a fine line I'm trying to walk--just hard enough so that's it's not a giveaway, but not too hard. Maybe a 2 or 3 on a scale of 10. So I guess I'm looking more for electronic "bells and whistles" than difficulty. I thought about have one extra display unit to show how many switches were set correctly at any given time, but then I realized that would be TOO easy--they would just have to cycle each switch and see if the count went up or down.

Maybe some kind of "victory dance" of leds surrounding the display when the solution is found? Maybe something that would play an audio clip (the theme of the cache is "Snoopy and the Red Baron--Snoopy has been shot down behind enemy lines and is being held hostage; the cacher has to get the coords of the military outpost and go rescue him--so it could play the "Snoopy vs. the Red Baron" song :)), maybe the display could be sympathetic and flash the correct settings in binary after a certain number of failed attempts...?

But please keep all the ideas coming. I'm collecting them for future caches that I want to make intentionally hard :D

If you're talking victory dance with LEDs and sounds, you're definetly going to have to go the micro-controller route. It would be silly not to IMO. I know you're just kind of soliciting ideas at the moment but sooner or later you'll have to pull the trigger an impliment one or several of them. Have you thought about where to start? Which idea or ideas are you leaning towards most at the moment?


If you only have one digit on then flash for 10-15 seconds the correct cordinates, the battery should last a long time

Only one digit will be on at any given time. The 6 digits will have to be multiplexed otherwise you'd need 42 I/O pins just for the displays. It will look like all the digits are on but the current draw will be the equivalent of only a single display being powered. Unless you're talking about PWM'ing the single digit to save even more power.
 

CAPT Bligh

New Member
If you're talking victory dance with LEDs and sounds, you're definetly going to have to go the micro-controller route. It would be silly not to IMO. I know you're just kind of soliciting ideas at the moment but sooner or later you'll have to pull the trigger an impliment one or several of them. Have you thought about where to start? Which idea or ideas are you leaning towards most at the moment?

OK, here's what I've currently got in mind. Six 7-segment LED modules. Eight switches. On the panel, on either side of every switch, will be a letter. If they position the switches to spell REDBARON, that will cause the correct coords to display. So if you look at the panel, you would see something like this:

RSABARTE
********
HEDIUON

where the switches are the "*'s" and the other letters are just random. So the correct switch position would be 1001100, spelling REDBARON. I just made this up; I'd have to come up with some better "wrong" letters so that it wouldn't be so obvious what the right sequence is.

There would be a limit switch on the lid so that the circuit energizes when it is opened.

With the switches in any order other than the correct one, numbers would displayed, but they would be wrong. There would be a ring of LEDs around the display, which would slowly flash red. If the switches are in the correct position, the ring of LEDs would turn green and would travel around the ring (hope you know what I mean--the lights would turn on and off to make it look like they were circling the display) and some sort of "ta-da!" sound would play.

And IDEALLY--after several seconds there would be a deep voice that said something like "place all switches in the down position before closing the box."

So that's where I'm at right now. Definitely not done thinking about it, but that's where I'm at. What do you think?
 

vne147

Member
So something like this is what you're thinking?

red_baron-png.39552
 

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MrDEB

Well-Known Member
the leds would use more current than the LCD(pretty sure) of coarse you could use PWM using say a 7555.
your basic idea but without the voice could be done without a PIC if you are unbale to program one or just want to do this as a DIMS (do it my self)
thinking a 7555, 4017 and some diodes.
 

vne147

Member
And IDEALLY--after several seconds there would be a deep voice that said something like "place all switches in the down position before closing the box."

What about just using toggle switches with covers like this? You can just make sure the switches are placed such that when the lid to the box is closed, each switch's cover gets closed. That would ensure all the switches get reset every time.

617-82002.jpg
 

MrDEB

Well-Known Member
I was thinking along the lines of reseting the switch positions after say 4 minutes.
if not guessed right the correct code (switch positions change)
lets say the correct code is 10011100
well after 4 minutes the correct switch position changes to 01100011
180 degree switch.
have in the directions indicating this.
 

vne147

Member
I was thinking along the lines of reseting the switch positions after say 4 minutes.
if not guessed right the correct code (switch positions change)
lets say the correct code is 10011100
well after 4 minutes the correct switch position changes to 01100011
180 degree switch.
have in the directions indicating this.

For this idea, how would you go about changing the "hint" letters above and below the switches?

I still like the idea of having the PIC randomly generate a solution each time it's powered up but I haven't figured out a really good way to give the user a "hint" like the OP wants. I think the idea that CAPT Bligh came up with for having mixed letters above and below the switches is the best solution so far in terms of mixing the fun and difficulty factors. Not to mention coolness factor which was one of the original requirements if I'm not mistaken.

I thought about using 16 segment displays in place of the letters so that the PIC can display different "hint" letters corresponding to the solution that's randomly generated at each powerup, but the I/O pin requirement started getting rediculous. I'm not sure what the limit is on multiplexing displays but 16 (16 segment displays) + 6 (7 segment displays) just seems like it would be pushing it. I guess I could use a port expander but not sure what the CAPT would think about getting into a more complicated solution. Of course, as it has already been discussed there is always the LCD option which would be the best solution in my opinion for power consumption, amount of information displayed, and I/O pin requirement.

So CAPT, do you want to stick to the completely do it yourself approach using standard logic ICs or do you want to get adventurous and go with a PIC. I can generate a schematic for you within a day or so if you want to go with the PIC idea.
 

CAPT Bligh

New Member
So something like this is what you're thinking?

red_baron-png.39552

Perfect!! Well...almost perfect. I need room for the "given" numbers in the coordinates. Stick-on numbers, same size as the LEDs. For my area, it would look like this:

N 38 33. XXX
W 076 04.XXX

where the X's are the LED displays.

How'd you do that?? It looks great. I would really like to have a nice graphics program. I've been using a student version of Corel 5 that I got years ago, but it's really out of date and I haven't even bothered to try and install it on my new laptop.
 

CAPT Bligh

New Member
What about just using toggle switches with covers like this? You can just make sure the switches are placed such that when the lid to the box is closed, each switch's cover gets closed. That would ensure all the switches get reset every time.

617-82002.jpg

I'm really liking that idea, and would be willing to spend the extra few bucks for the covered switches. And I could still have the Darth Vader voice audio that tells them to close the covers before they close the box. Thanks!
 

CAPT Bligh

New Member
So CAPT, do you want to stick to the completely do it yourself approach using standard logic ICs or do you want to get adventurous and go with a PIC. I can generate a schematic for you within a day or so if you want to go with the PIC idea.

I think I'll take you up on your very kind offer to help with the PIC. For one thing, I am really interested in following along as you do it so that I can learn myself.

I would like to stay with the standard orange-red LED displays rather than LCDs. It's just kind of a "retro" look that fits better with the theme I've chosen, and it's what I had in my mind's eye from the beginning. I can put plenty of power in the box so as to not have to worry about run time.

From what I gather, you won't have any trouble with the circuit for the displays. But is an audio track a bridge too far for this project? I just keep imagining a Darth Vader voice, or maybe the Jigsaw guy in the Saw movies, saying "Well done. Please record theses coordinates and close the switch covers," or some such. :)
 

vne147

Member
I think I'll take you up on your very kind offer to help with the PIC. For one thing, I am really interested in following along as you do it so that I can learn myself.

I would like to stay with the standard orange-red LED displays rather than LCDs. It's just kind of a "retro" look that fits better with the theme I've chosen, and it's what I had in my mind's eye from the beginning. I can put plenty of power in the box so as to not have to worry about run time.

From what I gather, you won't have any trouble with the circuit for the displays. But is an audio track a bridge too far for this project? I just keep imagining a Darth Vader voice, or maybe the Jigsaw guy in the Saw movies, saying "Well done. Please record theses coordinates and close the switch covers," or some such. :)

I think you'll be happy with the PIC solution. It really is the best way to make this project work. I shouldn't have a problem designing the circuit even with the sounds. It will take me a few days to choose the components and lay everything out. Then it will take probably about a week to write the code. Once that's done we can figure out how you want to go from there. For the "given" numbers you can use additional 7 segment displays that are hardwired to display the given numbers. I think it will look cooler and it will match. If I put togsether a parts list from Mouser.com, would that be OK?

BTW, the graphics program I used for the picture was just MSpaint but I do also use Gimp. It's free and does a lot. Just googole Gimp graphics software or something like that and you should find it.
 

CAPT Bligh

New Member
I think you'll be happy with the PIC solution. It really is the best way to make this project work. I shouldn't have a problem designing the circuit even with the sounds. It will take me a few days to choose the components and lay everything out. Then it will take probably about a week to write the code. Once that's done we can figure out how you want to go from there. For the "given" numbers you can use additional 7 segment displays that are hardwired to display the given numbers. I think it will look cooler and it will match. If I put togsether a parts list from Mouser.com, would that be OK?

OK, sounds good. Yes, go ahead and put together a parts list, including the switches with the safety covers. How much money are we talking about now?
 

MrDEB

Well-Known Member
An idea I had for changing the correct input as the picture showed. Only two possable inputs per switch but only one is correct.
Just put an ON - OFF - ON push-button switch on the lid.
you open the lid, a code is selected.
close the lid then open and a different code is selected.
Digi-Key
the switches for selecting the right code are DPDT switches. If you make it to difficult to get correct coordinates then people will give up and maybe throw the unit down the mountain.
A PIC is perhaps the best solution but may get to involved for the person trying to guess the correct coordinates.
 

vne147

Member
OK, sounds good. Yes, go ahead and put together a parts list, including the switches with the safety covers. How much money are we talking about now?

Not really sure about the parts cost yet. If I had to guess I'd say $10-$20 not counting the switches. The most expensive parts will likely be the switches. I can assemble a parts list with the micro-controller, LEDs, displays, etc but in all honesty you'd probably get the best price for switches going on eBay or something. I'll check and see what I find.
 

MrDEB

Well-Known Member
good source for switches

If here in the states look at
Giant CDS Cell Assortment-The Electronic Goldmine
here is an idea I had using an ON/OFF/ON switch.
every time you open the lid the code is changed from sat 1001 to 0110 etc.
the idea of a PIC is perhaps your best bet but don't have more than 3 or four combos.
may be too frustrating.
in my circuit it has only two different correct answers depending on the lid opening switch which is an ON/OFF/ON.
the 7555 is for PWM (conserve battery life)
the RED LED indcates a wrong answer.
the LED displays are hard wired to each desired segment so when you get a correct code entry the LED displays light up.
circuit needs work but it could be a basis for your project.
 

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CAPT Bligh

New Member
the idea of a PIC is perhaps your best bet but don't have more than 3 or four combos.
may be too frustrating.
in my circuit it has only two different correct answers depending on the lid opening switch which is an ON/OFF/ON.
the 7555 is for PWM (conserve battery life)
the RED LED indcates a wrong answer.
the LED displays are hard wired to each desired segment so when you get a correct code entry the LED displays light up.
circuit needs work but it could be a basis for your project.

MrDEB--thanks for the suggestions. I think I'm going to go with a unique solution, and just have some mechanical means of resetting the switches, such as safety covers. I showed some different possibilities to my wifely geo-partner, and she strongly preferred the simplest (like I said before, the longer I'm given to think about it, the more complicated I'll make it!). So I'll only need the PIC for the fancy dancing LEDs when the right solution is set.
 
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