If you're going to be making your own DIY EDTracker, here is the quick summary of what you'll be doing.
Source the parts
You'll need the hardware to make your DIY EDTracker. Some bits are pretty set in stone, like the SparkFun Pro Micro (or equivalent). For others, there is a choice to make - such as whether you want the cheaper MPU-6050 sensor or the better MPU-9250 sensor with magnetometer (that doesn't drift over time)... our recommendation would be the latter. You can decide on whether you're putting it all in some sort of enclosure, or not - it's completely up to you.
Solder it together into either protoboard or a PCB - or use breadboard if you prefer.
Next you have to put the software into the Pro Micro Arduino clone. This is called "flashing" or "programming" it. Again, you have options - if you want to get into the coding side of things, you can compile it from source code and flash it using the Arduino IDE. If you'd rather just get going with the minimum of fuss, our GUI tool can flash it for you.
The device will need calibrating prior to first use - a simple, short calibration process is needed so the device knows which way is which!
That's it, you're done... go enjoy your new-found head tracking in the game of your choice.