A requirement for the Quarterfinals (Stage 2) of the Hackaday Prize is to "Post a system design document, including a preliminary components list. The system design document should show what is working and what the Participant is building toward".

So: Here is the schematic, assembly drawing and BOM:

http://www.loligo.se/navigation/LPS_mini_v1.0_150423.pdf

Most parts work as expected. We have successfully measured the distance between several LPS / LPS Mini, but not yet had time to do proper tests of the on-board sensors intended for intertial navigation. We have only talked to them using I2C to confirm that they are responsive. Next step will not necessarily be a test with a LPS Mini on a cat, but it would be fun. It all depends on if we can find a stunt cat for our tests.