This is for the mircrobit competition.

You can't escape his gaze!  The eye of Sauron sees everything.  Thieves beware!

I figured since this was a BBC inspired competition, that I'd go the Tolkien route.  The code will be updated later, as I don't have a microbit yet. Runs off two AA batteries, in a carriage.

Attach it to a backpack or leave it on an item.  The Red LEDs will pulse periodically giving the flame a little life, and bluetooth tethering will send your phone alerts!

Print the flaming eye pieces with clear/translucent PETG or PLA.  This will allow the glowing red lights to highlight the flame.  I'll report back on a good infill setting once I've printed it.  I'm not sure whether the A&B buttons on front are neccessary for this code, so I uploaded 2 large yellow inlay versions with & without the cutouts for the buttons.

Print the large flame in red, and 1 of the large inlay pieces in yellow.  Print the other small pieces in yellow as well.

Print the Base in black  I have also included nut holes in the upper spire so you can embed m3 nuts in it (pause your print, and then place them) or, it should be a long enough hole with tight tolerances so that you won't even need a nut.  The nut is just for added assurance.

The Microbit goes behind the "eye" parts.  Print the spacers to place between the microbit and the red/back eye part to provide room for the LEDs.

Print the microbit mount in black as well.  I recommend PETG/ABS because it's where you'll hook it to a bookbag or other item using a carabiner/ large key ring or other means. 

secure the microbit mount to the spire with 2xm3 nuts and screws.  Then attach the microbit to the mount with m4 screws.  The M4 nuts get sandwiched between the large red flame and the larger yellow flame pieces.

Once printed, secure the microbit to the mount with 2 m4 screws & 2 nuts.

Secure the base part with 4x 25mm m3 screws

Run the battery power cable through the slot at the top and plug it into the microbit.

Non printed parts:

-Screws & nuts

-microbit

-double AA battery holder

-9v battery plug to attach to AA holder

-Plug microbit uses for 3v power in OR solder to microbit input keys

For the code:

Attach it to a backpack or leave it on an item.  The Red LEDs will pulse periodically giving the flame a little life.  When it is bumped, the lights will flash faster, and in a different pattern warning any would-be thief that his actions are being watched.  If knocked over, or the bluetooth connection is lost, an alarm will sound to keep thieves away.  Never lose your book bag, or any other important item again!  Place it against a door as an alarm.  

Assuming you can keep the microbit connected to your device via bluetooth (I know you upload with it, just don't know if the connection can stay live). It will send you a notification when bumped.  You can also wirelessly tether it, so that when it leaves the range of your bluetooth connection, an alarm will sound from the microbit and you'll receive an alert on your device.

Pictures will be uploaded later as soon as I print it.