Wanted to build myself an IR head tracking setup because I wasn't pleased with the performance and reliability of webcam face tracking. However, I didn't want to buy any of the existing over-priced tracking clips that even only used a solid USB connection or AA/AAA batteries. I also didn't want to quickly hack something together using my 3D printer or even cardboard and hot glue like some of ya do (you know who you are).

Instead I went about to design my own simple little tracking clip and I have to say I'm pretty happy with the results so far. So what goals did I set for myself?

• Low complexity of the device. I don't need a PCB, wires, plastic case and so on. Way too complex and nobody needs that if it works and isn't flimsy.
• It needs to be battery operated, but with a rechargable LiPo battery. Not your average giant AA batteries that I have to throw away after only like 30 hours of gaming so (?). Charging via USB-C obviously.
• Good, high-efficiency LEDs with a large viewing angle and equal as well as constant brightness over the whole battery life.

So what did I come up with? Since I needed a PCB anyways for the electronics, I opted to used that as the base framework for the whole device. The fiberglass of the PCB is quite rigid, sturdy and does not break easily. It's also very light and I won't need any cables. The area where all the active electronics are is large enough to pretty much exactly fit a tiny 250 or 350 mAh LiPo battery under it, which can be charged up while using via the USB-C port. It's only designed to take protected (!) LiPo cells (at the moment?), because there is no over-discharge protection on board. There are "only" various protections for charging and a fuse to prevent the battery from short-circuiting and going thermonuclear on your head or something.

To mount the thing to your headset simply use small cable ties through the mounting holes or strap on some velcro or something.

The rest of the project is pretty standard like most other projects of this type. I'm using a PS3 eye camera because you can get them for cheap and they have a high refresh rate. You will have to remove the integrated IR filter and replace it with something that blocks visible light, but not IR. How to do that is explained in this video:

https://www.youtube.com/watch?v=7jJfuP7YgPA

After you did that, install OpenTrack and follow this short guide to get the built-in open-source driver working for PC:

https://github.com/opentrack/opentrack/wiki/PS3-Eye-open-driver-instructions

That's it!

This project is still a work-in-progress to keep improving the overall mountability, accessibility of the switch and USB-C port as well as the battery life (easily like 10% more is possible). I'm already in the works for an improved version that keeps the overall LED footprint, but reduces the electronics section a tiny bit, increases battery life and adds upon the mounting options. Stay tuned for more!

I might add production files and schematics in the future when I feel comfortable doing so, definitely let me hear your thoughts about that!