So yeah, like the title says i found some plans online for a headtrack device, here is the link with the instructions: https://www.dropbox.com/s/0bugsxhhth...ceTrackHAT.pdf
I am not going to rewrite the instruction since they are online they are pretty clear and well writen, i will just give some extra "tips" and some photos.
I used the arduino pro micro (ATMega-32U4) and a breakout module MPU-6050 (3 AXIS Gyroscope Accelerometer) with a total cost around 10euro. You are also going to need some thin cables , the twisted wires from a LAN cable will do. Would be better if you find cables with a single wire inside the isolation (no idea how they call them in english), they are a bit harder and they keep the form that you give them.
There is some soldering required (5 contacts) , although its simple if you have no idea how to do it, find someone who knows or find a good online tutorial and try it.
Follow the instructions to the letter, don't skip any steps and read all of it first and then go step by step.
Somewhere in the instructions says "It it Important NOT to move the sensor for several seconds after it powers up.Otherwise you will have some small to severe lag on your Z-Axis" yeah he is saying the truth don't skip it.
When you mount the build on your headset make sure you ziptie or ductape your usb cable to avoid any stress on it.
If you can get a small box to put it on it would be ideal to avoid any dmg by mishandling your headset,
also a PCB is not a bad idea for those who know how to make one (i will upload the printable plans later this week)
Try not to ductape the circuits specially the big black chip.
The final build its really small (usb drive size) and it works perfect, the only disadvantage is that you cant move your head forward to zoom like the IR trackers can (with the given software),
Here are some photos :)