With the miniaturization idea validated, we focused on using only 4 photodiodes as putting them on a tetrahedron allows having at least 2 visible ones by the lighthouses, for any rotation.

Main parts

- MCU + BLE: To save some space, we use a fairly small nRF52 module (8 x 8mm) by Insight.

- IMU : To save some time, we use the only 9DoF sensor that performs the full sensor fusion, the bno055 by Bosch.

The PCB design files are on upverter.com/hivetracker, but here is an overview of what it looks like:

It was finished and built during yet another Hacker Trip To China, hanging out with the Noisebridge gang and tinkering with magic parts found in the Shenzhen electronic market.

Making in China

Note: there are 2 periods of 1 week when almost everything is closed in China, lunar new year is probably the most famous, but the golden week holiday is very serious too.

This board was made during the golden week so it was not easy, but even though some chosen parts are approximative, some manufacturers such as smart-prototyping.com are more flexible and they got the job done: