Geocache with GSM shield.

Official Hardware Retired GSM Shield
1

Hi,

I know the basics of arduino, but keep myself questioning how to do the following:

  1. The person comes to my geocache (geocache is a box that people search with GPS signals.)
  2. Person text to a certain number.

Here comes the complicated part:
The arduino itself has to be inside my house, but i'd like to have a small wireless circuitboard in the actual container thing. The arduino, sort of, has to send a signal to the small circuitboard. Than the circuit board activates a servo motor which unlocks the cache and plays a small sound.
This is a sort of schematic:

  1. Text arrives, gives signal from shield to uno.
  2. Uno sends wireless signal to Nano. http://www.instructables.com/id/Arduino-Wireless-Serial-Communication/
  3. Nano executes his task, play sound i saved to SD card and opens container with servo motor. (3 minutes long it is opened)
  4. Nano stops his task, put servo back in place.
  5. Next geocacher can send text again.

I'd like to have a few tips, and maybe some help?
I do have skype and my English is pretty OK.

Greetings,

Daan
Holland