Arduino Headtracker

By using an Arduino and an appropriate IMU you can for very little money build yourself an excellent headtracker similar to products such as TrackIR.

You can see a short demo video of my own build here: https://www.youtube.com/watch?v=QpO1Wty3F3I

This repo contains both the Arduino code and the FreePIE script to get your headtracker working.

Hardware

Below is the hardware I used, you can substitute with your own parts as you see fit.

• Arduino Nano
• GY-85 9DOF IMU

I prefer the Arduino Nano due to the combination of formfactor and the USB port but any Arduino should work. I have ordered a couple of cheaper MPU-6050 IMUs to try if they work well, as that would cut the hardware cost in half, but they have not arrived so I can not yet vouch for them.

Wire up the IMU to the Nano over the I2C bus, try to orient the IMU in a way that makes sense. Preferrably the X axis should point towards your screen once the headtracker has been mounted.

When you've verified that the software works you can mount it on top of a headset or something similar.

On the Arduino

Before you load the provided sketch you need to install the FreeIMU library for Arduino, found here: https://github.com/Fabio-Varesano-Association/freeimu

For this to work with the GY-85 IMU I had to open the arduino\libraries\FreeIMU\FreeIMU.h file, comment out the original version (I think it was #define FREEIMU_v04) and uncommend the following line:

#define FREEIMU_v03

The FreeIMU_yaw_pitch_roll sketch provided in this repo is very close to the original example from the FreeIMU library with the output changed to comma-separated values. Upload it to your Arduino and verify the output through the serial monitor. You should see a lot of values rolling by similar to this:

145.49,31.35,0.91

On the PC

Download and install FreePIE from here: http://andersmalmgren.github.io/FreePIE/

Configure the FreeIMU plugin to the COM port of your connected Arduino headtracker, and load up the FreeIMU Headtracking.py script. Configure it to your liking and run it by pressing F5. If you have DEBUG set to true you can see both the input and output values under the Watch tab at the bottom

Games

The games listed below have been tested with this setup and should hopefully work well.

Assetto Corsa

I found the following settings to behave very well in this game:

OUTPUT_TRACKIR = True
TRACKIR_MULTIPLIER = 10 

You might want a different multiplier but this felt natural for my setup with regards to size and distance to the monitor.

ARMA 2

For some reason I have not been able to get ARMA 2 to work with TrackIR, however the following worked for me:

OUTPUT_FREETRACK = True
FREETRACK_MULTIPLIER = 0.001

This worked nicely when flying helicopters or driving cars.