BLE beacons for geocaching

[andersborg]

When talking beacons for geocaching most people seem to mean NFC tags. Am I right?

 

There's a new kid in town called BLE beacon or specifically iBeacon (for Apple's flavor of it).

 

As such beacons just broadcast a unique(ish) set of IDs (uniqueness is not enforced) there's need for an app that listens for beacons.

 

The app then determines what to do based on the IDs.

 

Pros:

- You'll get notified a distance away that you are close.

- You don't have to physically find the geocache per se, if all related content is digital and shown via the phone, including diary etc.

- Due to this, the beacon could be put inside of environment protection and completely hidden away.

- Works both for iOS and Android phones. NFC only works for Android phones.

 

Cons:

- You need a special app.

- Beacons for geocaches would most likely have to battery-powered, which leads to maintenance.

- They are expensive relative to NFC tags: $10-20 rather than $1-2.

- They might be interesting to steal due to that, so "hooligans" might go to great lengths to get hold of them.

- They might not be as environment-resistant. Even when put in a cover, there's still the issue of low temperatures.

 

Therefore I see them as more interesting for short duration geocaching contests, orienteering and such, than perpetual caches.

 

Has anyone tried this?

 

Regards,

Anders

[knowschad]

In my part of the world, the term "beacon" when used in geocaching simply refers to any likely spot to hide a cache. When approaching a big hollow stump in the woods, one cacher might say to the other, "I'll bet its in that big old beacon over there!".

 

What you are talking about sounds similar to the Garmin chirp or, as you say, an NFC tag. Neither one has really been used extensively for geocaching in my area.

[+Uncle Alaska]

For me beacon means a device that sends out a radio signal (often repetitive). I have found caches with the following beacon types: chirp, AM/FM broadcast, and wifi/internet.

 

I think NFC stands for near field communications, which is something akin to using google wallet or apple pay...the radio field operates at the inch(es) level. Chirp and other beacons (ANT+, or others I mentioned) operate at many feet distances.

Edited March 2, 2015 by Uncle Alaska

[+MartyBartfast]

When talking beacons for geocaching most people seem to mean NFC tags. Am I right?

 

 

To me a "beacon" refers to Garmin CHIRPs not NFC tags. What you describe is almost exactly what the CHIRP is/does, and they've been around a few years now, there are a few out there but they're not common probably due to cost maintenance (changing batteries).

[+Walts Hunting]

Pros:

 

- You don't have to physically find the geocache per se, if all related content is digital and shown via the phone, including diary etc.

 

Regards,

Anders

A container that has a logbook is required with a couple of exceptions. The beacon would have to send the coordinates to that container.

[+Touchstone]

In geocaching, a beacon is a wireless device that transmits a brief message which can be used to find a geocache.

 

Link for reference:

 

Beacon Geocaches

[+Team Microdot]

Chirp and other beacons (ANT+, or others I mentioned) operate at many feet distances.

 

I've only found about three chirp caches but not one of them could be detected at many feet distances - had to be right on top of them.

[+Uncle Alaska]

Chirp and other beacons (ANT+, or others I mentioned) operate at many feet distances.

 

I've only found about three chirp caches but not one of them could be detected at many feet distances - had to be right on top of them.

Must be the way they were placed...I have one for a cache that can be received about 150-200 feet away. It is up in a tree.

[+The A-Team]

I've only found about three chirp caches but not one of them could be detected at many feet distances - had to be right on top of them.

Must be the way they were placed...I have one for a cache that can be received about 150-200 feet away. It is up in a tree.

They may also have had dying batteries. I've found a few Chirp caches, and I've been able to detect them in the 50-150 foot range (an assumption based on where I think the Chirp is actually hidden). The official range is 32 feet or 10 metres, but their range seems to be better than that in the real world.

[+Team Microdot]

I've only found about three chirp caches but not one of them could be detected at many feet distances - had to be right on top of them.

Must be the way they were placed...I have one for a cache that can be received about 150-200 feet away. It is up in a tree.

They may also have had dying batteries. I've found a few Chirp caches, and I've been able to detect them in the 50-150 foot range (an assumption based on where I think the Chirp is actually hidden). The official range is 32 feet or 10 metres, but their range seems to be better than that in the real world.

 

In the cases where chirps have been detected from the quoted distances, can I ask how they were hidden?

 

Two of the those I have found were inside film pots to protect them for the weather and were only detectable when within inches of the GPS device - even when removed from said film pot.

[+The A-Team]

In the cases where chirps have been detected from the quoted distances, can I ask how they were hidden?

 

Two of the those I have found were inside film pots to protect them for the weather and were only detectable when within inches of the GPS device - even when removed from said film pot.

I've never actually located any of the physical devices for the Chirp caches I've found. They're not intended to be found, so I don't go looking for them. I believe they're often attached (non-intrusively, I hope!) to something like a tree with a fairly clear view of the intended reception location.

 

I would have thought that the film containers would explain the poor range, but it's strange that it didn't change even when removed from them. Anyway, it's my understanding that they're already weatherproof, so it isn't necessary to further weatherproof them. The ones we have around here are just out in the open and haven't had any problems other than run-down batteries.

[+niraD]

The chirp cache that I've done could be done without a chirp device. The coordinates transmitted by the chirps were also written on the outside of the containers the chirps were placed in.

 

But for one stage, the CO did mention that you needed to be very close to the chirp, because its location (inside a metal fence post) blocked its signal. I couldn't verify the difference though, because I was finding the containers instead of using a chirp receiver.

[+MartyBartfast]

 

But for one stage, the CO did mention that you needed to be very close to the chirp, because its location (inside a metal fence post) blocked its signal.

 

Back when CHIRPS first came out I remember someone discussing placing one inside a metal tube with one end blocked, so that the signal would be "aimed" out of the open end, therefore you not only had to be in the area but had to be aligned with the tube so you were inside the beam of the CHIRP. I don't know how effective that would be, or whether they actually implemented it, but it sounded a neat idea at the time.

[+NYPaddleCacher]

Two of the those I have found were inside film pots to protect them for the weather

 

because we all know how well film pots will protect a log sheet.

[+Uncle Alaska]

Mine is a wire hanger about 8-9 ft up in a tree, put a piece of camo duct tape on it to make it look like a leaf.

[+Team Microdot]

Two of the those I have found were inside film pots to protect them for the weather

 

because we all know how well film pots will protect a log sheet.

 

I know - and yet the seemed to work fine for the chirps!

 

Maybe if you're a CO who likes to use film pots for caches it should be mandatory to use a chirp in place of a logbook

[+MartyBartfast]

 

I know - and yet the seemed to work fine for the chirps!

 

 

Well considering the CHIRP is itself waterproof the film pot is pretty much unnecessary.

[+Team Microdot]

 

I know - and yet the seemed to work fine for the chirps!

 

 

Well considering the CHIRP is itself waterproof the film pot is pretty much unnecessary.

 

I seem to remember one was at ground level - maybe under a stone - in which case I expect the outer container was for physical protection as much as anything.

 

Personally I'd have placed it in an elevated position in a conveniently adjacent structure.

[Mr.Yuck]

In my part of the world, the term "beacon" when used in geocaching simply refers to any likely spot to hide a cache. When approaching a big hollow stump in the woods, one cacher might say to the other, "I'll bet its in that big old beacon over there!".

 

Believe me, your area is the only one. And even with The Geocaching Vlogger and The Geocaching Doc using it all the time, it's still not catching on with anyone.

 

And talk about not catching on, I am only aware of one single solitary chirp cache in my entire region.

[+kunarion]

In the cases where chirps have been detected from the quoted distances, can I ask how they were hidden?

 

Two of the those I have found were inside film pots to protect them for the weather and were only detectable when within inches of the GPS device - even when removed from said film pot.

Both of mine are on tree branches, 4 and 10 feet high. They're wrapped to the branch with camo duct tape, and a very high difficulty if one was to try to find the actual device (The Chirp transmitter is not supposed to be found, only the signal is to be found). I'll swap them with dry, tested Chirps once a year. The Chirp can send a “Low Battery” message, but I'm not waiting til that happens.

 

The signal gets severely affected with the Chirp on the ground. Mine are elevated. It is unacceptable to need to be especially close to the Chirp to get the signal, so I make sure it at least works at a suitable distance with my GPSrs. One issue is the GPSr itself. You can be in range just fine, and the GPSr detects nothing – it sometimes takes a while to wake up and start doing the Chirp thing. Or maybe it's the Chirp not waking up, or a little of both.

 

Even if it's working well, there's plenty of weirdness with Chirp. Upon detection, the GPSr beeps and the display changes, and cachers stop walking to see what's happening. But they are at the edge of the radio reception and therefore must continue toward GZ, to get a good signal. Now they have data slowly loading. In this low signal area, the GPSr can freeze, then eventually time out.

 

The quality control of Chirp manufacture is not good. One of mine has a range of less than 16 feet, which is useless for Geocaching. People would have a tough time finding and maintaining the signal, to get the data. So I use that one for testing. For my cache, it's gotta have at least a range of 50 feet, or it will be even worse for cachers than Chirp usually is.

Edited March 3, 2015 by kunarion

[+Team Microdot]

The quality control of Chirp manufacture is not good. One of mine has a range of less than 16 feet, which is useless for Geocaching. People would have a tough time finding and maintaining the signal, to get the data. So I use that one for testing. For my cache, it's gotta have at least a range of 50 feet, or it will be even worse for cachers than Chirp usually is.

 

The ranges you cite here would have been welcome on the one's I've found.

[+kunarion]

The ranges you cite here would have been welcome on the one's I've found.

If cachers must find the Chirp itself, the CO might as well just have a note with coordinates in that film pot . The way Chirp should work, you'd only need to walk along a trail to receive the next waypoint.

 

Did you make a decent log about the issues, in your Found It log? On my Chirp cache page, I request details, although cachers tend to not say. Some peoples' "Chirp Capable" GPSrs don't seem to work with Chirp at all. On my cache, people had trouble receiving data at one stage or the other, when their companions had no problem.

 

When I was setting up my cache, my GPSr was getting the data OK, but crashing when I told it to send me to the next waypoint -- until I did a soft reset. It all seems highly experimental. I wouldn't rely on Chirp as a navigational device.

Edited March 3, 2015 by kunarion

[+Team Microdot]

The ranges you cite here would have been welcome on the one's I've found.

Did you make a decent log about the issues, in your Found It log?

 

TBH I didn't realise that any issues existed - just assumed that the device had a very short broadcast radius - they do run, I think, on a button cell so I never expected it to blow the doors off.

 

I suppose if I'd had a better experience on a previous occasion I might have reached the conclusion that a particular chirp wasn't performing as it should - but I've never had such an experience.

[+kunarion]

TBH I didn't realise that any issues existed - just assumed that the device had a very short broadcast radius - they do run, I think, on a button cell so I never expected it to blow the doors off.

 

I suppose if I'd had a better experience on a previous occasion I might have reached the conclusion that a particular chirp wasn't performing as it should - but I've never had such an experience.

I have a lot of info on my cache page, to help cachers figure out what's going on. My "Chirp Waypoints" are in no way exactly at the device, which I did deliberately. That's why I must use Chirps that transmit far.

 

I made mine a Chirp cache, PMO, Unknown Cache Type, and aggressively hid the Final, with the intent that this one will not be hunted often, and won't be discovered/muggled by passers-by. After its previous version was muggled several times, I designed this one to be a much more quiet cache. So that's how it became a Chirp cache.

Edited March 3, 2015 by kunarion

[+niraD]

Two of the those I have found were inside film pots to protect them for the weather

because we all know how well film pots will protect a log sheet.

Then again, if the film pot is never opened by those seeking the cache, because chirp users will just use the chirp signal, and because non-chirp users will read the coordinates of the next stage on the outside of the film pot, then it wouldn't be hard to add a little sealant to the lid of the film pot. Once a year, you can replace the film pot's sealant when you're replacing the chirp's battery.

[+moor to sea]

I put an ibeacon in my chirp cache a while ago so people without chirp GPS can use an Android or iphone instead.

I have set the major, minor to the last 5 digits of the lat and long.

The range of the more powerful ones is very good.

 

I am tempted to set a cache so the range finding feature can be used to zero into the cache, beacon.

Would put it on a path so a bit easier to zero in..just put the last digit of the lat long in the maj,minor field to help in the last few yards.

 

GC58M19

Edited April 3, 2015 by moor to sea

[+jellis]

I have 3 chirp caches. One is the first one ever placed in California. It's a puzzle I call it A Rare Bird. The beacon can reach about 40 feet and since I put it out I replaced the batteries 3 times.

The second one The Unique Bird is a 3 stage Puzzle (multi). Both first 2 stages are chirps and then the final. Only had to change the batteries 2 times. The third one High Tech Hobo Stew is also a Puzzle (multi) with each stage being a different type of stage, like UV, QR Codes,the Chirp then the final. I have yet to change the battery on that one.

[+Pistol Packin' Mama]

I just got back onto geocaching after several years away from doing it. This beacon thing is new to me. Can you guys suggest a good app. for an Android phone? I guess to receive chirp signals. 

[+kunarion]

2 hours ago, Pistol Packin' Mama said:

I just got back onto geocaching after several years away from doing it. This beacon thing is new to me. Can you guys suggest a good app. for an Android phone? I guess to receive chirp signals. 

 

Search the Google Play store for "ANT+ Plugin Sampler".  It's not very polished, and it's got a kind of hacker vibe to it.  But it's all you need for a Samsung tablet, and probably their phones, to read Chirp info.  The store will tell you if it's compatible with your phone.  I bought an Ant+ USB dongle for my old Acer tablet, and that required other plugins (also in the Play store), mentioned in the dongle's instructions.

Assuming you get ANT+ basically working with your phone, another thing you might look into is an App called "Locus Maps Pro".  It is supposedly getting support for Chirp.  The nice thing about that is, Locus Maps works as a Geocaching App, so it (I'm guessing) would read and save data.  The "Sampler" App requires you to write down the data, then type it into some App.  I never found the Chirp feature in Locus Maps, but I'll check it from time to time, and if I get that working, I'll mention it somewhere around here.

Edited August 30, 2017 by kunarion

[+gbonnet]

I may be very late to react but following relates what I've done.. Please note that the cache is not (yet) published.

I used a very standard 20$ bluetooth LE ebeacon powered by a CR2477 battery (they say 1.5 year lifetime ?? I doubt) Its range is about 100 feet.
You can tune the power  to decrease or increase  the range if needed. -The beacon comes with a smartphone based  app so you can configure it-

I managed to :

• Configure the beacon with a relevant name so you know its a geocaching related beacon (guess you can broadcast the cache id GC...)
• Configure the beacon with an ID (UUID) which contains the target cache coordinates  so when you detect the beacon, you catch where the cache is located.. (note that it is up to the user to find that uuid contains clear or encoded  target coordinates.. depend on how you describe your mystery.. can be more or less difficult to realize that coordinates are hidden in the ID)
• I found (in play store) at least 4 free apps on Android which scan for beacon and show the name and UUID (IMHO, the best is  -Bluetooth LE Scanner-). I believe such apps do exist for IOS too.

In a nutshell : the cache only requires well known and widely available parts (a beacon and an app on a smartphone). It is run as a mystery cache since you have to : 1)  go there,  2) walk a bit till you receive the beacon,   3) catch the cache location and  4) go get it.

Question is : does it make sense wrt geocaching philosophy ???... I dunno...

my five cents

[+kunarion]

1 hour ago, gbonnet said:

I may be very late to react but following relates what I've done.. Please note that the cache is not (yet) published.

I used a very standard 20$ bluetooth LE ebeacon powered by a CR2477 battery (they say 1.5 year lifetime ?? I doubt) Its range is about 100 feet.
You can tune the power  to decrease or increase  the range if needed. -The beacon comes with a smartphone based  app so you can configure it-

I managed to :

• Configure the beacon with a relevant name so you know its a geocaching related beacon (guess you can broadcast the cache id GC...)
• Configure the beacon with an ID (UUID) which contains the target cache coordinates  so when you detect the beacon, you catch where the cache is located.. (note that it is up to the user to find that uuid contains clear or encoded  target coordinates.. depend on how you describe your mystery.. can be more or less difficult to realize that coordinates are hidden in the ID)
• I found (in play store) at least 4 free apps on Android which scan for beacon and show the name and UUID (IMHO, the best is  -Bluetooth LE Scanner-). I believe such apps do exist for IOS too.

In a nutshell : the cache only requires well known and widely available parts (a beacon and an app on a smartphone). It is run as a mystery cache since you have to : 1)  go there,  2) walk a bit till you receive the beacon,   3) catch the cache location and  4) go get it.

Question is : does it make sense wrt geocaching philosophy ???... I dunno...

my five cents

 

Your description is typically how a "Chirp" cache stage works.  I've often thought of hiding a Chirp right next to a trail, so cachers simply have to walk past (even walk past with Chirp detection turned on and discover the coords and codes by accident!). That would be some cool FTF story one day.

I've owned two kinds of Bluetooth "tracker" tags, but neither were useful for Geocaching, since I had to "pair" the device with my phone.  This means one person (the owner) can find it.  If the new Apps can pull some data without pairing, that's pretty cool!

But since Chirp can also be re-programmed by pretty much anybody (which is one reason I archived my Chirp cache), I haven't done much with them lately.

If you want to see how a cache page may be set up, check out my Chirp cache.  It has text that covers lots and lots of "gotchas".  People still had plenty of trouble hunting the things.  And the battery life depends mostly on the individual battery, and the individual device.  Some are fine, some are terrible, and you won't know til it all goes bad.  So as a Cache Owner it's best to set up a schedule to test the device.  I had extra Chirps so I could swap out the whole thing, and replace batteries at home once I cleaned and dried the previous one.  Ideally the cachers don't find the actual device, in which case you must hide it super aggressively while still permitting a strong signal.  And you as the CO must be able to find it again.  One of mine has fallen from a branch and is somewhere among boulders in a forest, still functioning... weakly...

 

Edited November 19, 2017 by kunarion

[+gbonnet]

I appreciate your answer and agree with. I think that 2 topics are still openned

1) Is it allowed to install an app on a smartphone?

Have no clear opinion but only few  guidelines :
 a)- using a smartphone is mostly allowed now (this is in the normal trend. have a look backward on paper maps and pencils like sailors did to get their location
 b)- the smartphone should not be mandatorily "connected" to a netwok... we must be able to hide - and find- caches all over the world (except in deep sea....may be !)..there can be no network in the area
 c)- the app must be available in an official store and for the various (not too old) brands of phone. This is to avoid viruses, trojan and other hacking tricks
 d)-But  it means that geocaching (or at least some kinds of caches)  requires a smartphone.. not everybody owns one.

Am sure geocaching responsibles are fully aware of this topic and It should be great to find guidelines (or even rules) which are periodically updated and tackle those and others similar concerns.

2) Easy to use technology

Am a bit more doubting about finding an answer
 - On one end; every required part (but cars to reach the zone!  ) should not be restricted by any commercial concern... Oops.. Chirp is not in that view
 - On the other end, it has to be very easy to setup (user view) and at no or very low cost. Easy means that we must enjoy geocaching way more than technology.
  as far as I understand the previous post from Kunarion, BLE and maybe Chirp  remain questionnable.

Again geocaching responsibles are aware of... and being a reviewer becomes difficult and surely some will accept, some will not.... and since world evolves, decisions may vary.

So back to my concern, I would state that using a smartphone and an app is not against geocaching philosophy if it complies with second point..
Am I openning a pandora box? I dont think so and am convinced that geocaching has to deal and will deal with. (always being a pleasure while not staying in the "good old days") 

.... and yes : ble ebeacon dont require any pairing...
 

Edited November 20, 2017 by gbonnet

[+kunarion]

3 hours ago, gbonnet said:

I appreciate your answer and agree with. I think that 2 topics are still openned

1) Is it allowed to install an app on a smartphone?

Have no clear opinion but only few  guidelines :
 a)- using a smartphone is mostly allowed now (this is in the normal trend. have a look backward on paper maps and pencils like sailors did to get their location
 b)- the smartphone should not be mandatorily "connected" to a netwok... we must be able to hide - and find- caches all over the world (except in deep sea....may be !)..there can be no network in the area
 c)- the app must be available in an official store and for the various (not too old) brands of phone. This is to avoid viruses, trojan and other hacking tricks
 d)-But  it means that geocaching (or at least some kinds of caches)  requires a smartphone.. not everybody owns one.

 

A beacon cache may not be published if it requires one particular App or phone.  Many of the beacons have Apps that run on popular operating systems.  So choose the beacon and protocol that has the widest support.  A cache can be published regardless of whether everyone has a phone.

At least one protocol doesn't even need a separate "beacon" App.  The browser has support for it, Google Chrome, I think, which is pre-installed in many phones.  If cachers could grab coords from a beacon and send them to Google Maps or whatever, that would be pretty cool.

As for it not being "easy", the cache may still be published. The problem is that when cachers follow the instructions and set it all up, they expect that it will lead to a find.  In many cases, they will arrive at the cache stage and not detect the beacon, or have a phone crash, or any of a number of issues caused by using a "beacon App".  The Cache Owner will be tech support for installing and using the Apps, so the Cache Owner must be available to answer questions, and must be testing the beacon to be sure it works as advertised.

Edited November 20, 2017 by kunarion

[+niraD]

4 hours ago, gbonnet said:

 b)- the smartphone should not be mandatorily "connected" to a netwok... we must be able to hide - and find- caches all over the world (except in deep sea....may be !)..there can be no network in the area

FWIW, InterCaches require you to be connected to a network. I don't think that limitation is necessary, other than the fact that you can't place network-dependent caches in an area that doesn't have coverage.

[+arisoft]

15 minutes ago, niraD said:

FWIW, InterCaches require you to be connected to a network. I don't think that limitation is necessary, other than the fact that you can't place network-dependent caches in an area that doesn't have coverage.

The difference is that Intercache must be mystery cache type. I have made a field puzzle mystery which needs on-line connection to load javascript app to browser on site.

[+kunarion]

15 minutes ago, arisoft said:

29 minutes ago, niraD said:

FWIW, InterCaches require you to be connected to a network. I don't think that limitation is necessary, other than the fact that you can't place network-dependent caches in an area that doesn't have coverage.

The difference is that Intercache must be mystery cache type. I have made a field puzzle mystery which needs on-line connection to load javascript app to browser on site.

 

If it's a cache that is both a "beacon" and needs to "get info online", that will be an interesting challenge for a CO to set up and keep functional so that cachers get consistent finds.  I hope it's clear on the cache page that it's both.  Like some others, I have no data service on my phone.

[+gbonnet]

hi

A bit of tech explanation on beaconLE : this beacon works like a  bluetooth device (earphone, etc..) except that it  only broadcasts some fixed data (name, UUID ..) There is no send/receive between  beacon and smartphone : beason broadcasts and smartphone receives (So no pairing.is needed)
The smarphone has to scan for beacon and to display data on the screen...( BTW, the LE standard now allows to compute (and display)  the distance from beacon - assuming you configure the beacon with the standard emission power: no more no less).

As a consequence, an internet browser is not relevant and up to now, the scan app is not preinstalled on the phone (it would not be of any need but topology and geocaching...) I bet it will never be part of preinstall app like skype or others. So a beacon (whatever the technology) will always require an app from the store.

Im not pushing forward or backward... just trying to know where is the current border line between allowed and disallowed caches....
as of this thread, I would say : 1) a smartphone is accepted   2) the smartphone may require or not to be connected  assuming the cache can be found with or without coverage 3) no app  is needed.. (note that the geocaching app is not required as such but is very very helpful !)

Ill make your day saying that : if geocaching app includes bluetooth LE scan... there would be no more issue !

Off topic  :  ebeacon LE is intended to be used to advertise  when walking across  stores : you get a notification on your phone about the store and its current rebates, sales, openning hours, services, etc etc

[+NYPaddleCacher]

4 hours ago, arisoft said:

4 hours ago, niraD said:

FWIW, InterCaches require you to be connected to a network. I don't think that limitation is necessary, other than the fact that you can't place network-dependent caches in an area that doesn't have coverage.

The difference is that Intercache must be mystery cache type. I have made a field puzzle mystery which needs on-line connection to load javascript app to browser on site.

Intercaches also do not require a native mobile app (it's a web application, accessible with a browser).  I did my first in Kansas City a few weeks ago and really enjoyed it.

[+gbonnet]

FYI : here is my conclusion.. Guess I can't go way further

Requirements :
 -  A smartphone without any additionnal application and no  need to be connected to a network
 -  A BLE ebeacon
 -  No pairing required
How to :
 - The smarphone uses the standard bluetooth search command  to find the beacon (It of course do exists in any smartphone and  other wireless client devices).
 - Configure beacon for highest broadcast power (+4dbm). This  allows for about 100 -150 feet true range
-  Configure beacon for the lowest broadcast rate (1 per second) for max battery life time
-  And most important : set the beacon name with the cache target coordinates : (I did set to Naabbbbb-Wxxyyyyy which is 12 alpha+5 numeric  for my current beacon and is displayed on the smartphone.

It is then similar to a mystery cache and looks like Chirp. In addition, you have to go withing the broadcast area to catch the target coordinates. The cache may be described an easy or difficult way to find.. up to the owner. 

 

[+gbonnet]

On 24/11/2017 at 1:33 PM, gbonnet said:

 here is the cache : https://www.geocaching.com/geocache/GC7EJ2Y_promenade-de-geek