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How to hide and find intelligent treasures using a mobile phone



Wouldn't it be cool if you were walking on the street checking your phone one day and you saw this?

Treasure Nearby

Let's update geocaching to this decade by hiding some caches that could be found by anyone without even knowing what geocaching is:

This is what we're going to build:

  • RuuviTag = waterproof geocache (aka treasure)
  • Battery life: up to several years
  • Requires no pairing
  • Is broadcasting a URL address Android/iOS mobile phones can hear

Let's get started!

First, you'll need to make sure you're running the correct firmware on your RuuviTag. Transform your RuuviTag to an Eddystone proximity beacon with the help of these instructions.

Then, we suggest getting first familiar with Android Nearby notifications and the Physical Web. They're the enablers which make possible for people to see the beacon messages without any software installed on their phones. Note that currently, iOS doesn't show notifications natively and Chrome web browser has to be installed.

The easiest way to create caches is to use a web tool created by eibt (check the comments below).

You can also make a simple web page with necessary metadata fields. Something like this:



Upload it to your server. If the URL is too long, you can use a URL shortener.

Configure the RuuviTag to broadcast the correct URL. Check the transmission power is at the range you want. This depends fully on the location of the cache. To make sure the setting is correct, you should probably try to "find" the treasure by yourself by moving closer to where it's hidden. Usually, -12dBm should do it but you can also use stronger signal settings (+4dBm is the max).


In order to make the Physical Web work, you'll need to setup the RuuviTag to broadcast a URL which points to an HTTPS capable server. This is important. The nearby beacon won't show up on users' phones if the server doesn't support HTTPS.

If you use the web tool created by eibt, you don't need to worry about this.


Share your project

#ruuvitag / @ruuvicom

Ruuvi Innovations Ltd (Oy) / Finland

Web Design Niku Creative