Frequently Asked Questions - General

FAQs - General

General non-specific questions

Drift, or axis creep, happens on the X-axis (or "yaw" axis) with earlier MPU6050-based devices because the sensor cannot accurately measure movement around a vertical axis. The sensor relies on gravity applying 1G of force onto the axes to provide a known reference point. However, the x-axis pivots around a vertical - imagine a line straight down through the top of your head, around which your head spins. This is in perfect line with gravity, so gravity does not apply across that axis when you're looking dead-ahead - gravity runs straight down the axis line.

This prevents the sensor from being able to 100% accurately measure rotation when in that position, but it uses an internal process of axis fusion to estimate it. It does a pretty good job, maintaining dead-ahead for normally 30 minutes or more - but it can go off to one side over time... this is the drift that people speak of. Typically you should not be seeing drift all that regularly - you should be able to play for at least half an hour before needing to re-centre the device. Accurate calibration is the key to minimising drift.

The EDTracker Pro and MPU-9150 versions of the device do not suffer from yaw drift when calibrated correctly.

If you make your own, it really is up to you and depends what you use - size of breadboard, for example.

If you use our PCB design, it is 37mm x 27mm. Total height of the device once assembled is approximately 28mm excluding the button.

The project started off on the Elite Dangerous community forum, and most of the initial enthusiasm was to provide head tracking within that game. It was the ED community that helped develop it. In reality, there is no reason why the board couldn't be used with any other game that supports joystick input for head tracking.

In short, you strap it onto your head.

In detail, read the article on using.

No, the device draws power from the USB port of your PC.

We all have day jobs and this is just a little fun project on the side. So please bear this in mind when contacting us, we're not being rude, we're just probably busy, but we'll get back to you as soon as we can!

EDTracker models 3 degrees of freedom (3DOF) - pitch, yaw and roll. So your head twisting and looking around is what is monitored and reported.

It does not report lateral or vertical movements of your head - so any sideways movement of your head, or moving it towards (or away) from the screen. This is what is commonly referred to as 6DOF.

Note: do not confuse true "degrees of freedom" with the marketing hyperbole touted by the sensor manufacturers. For example, the Invensense MPU-6050 is touted as "6DOF"; the 9150 as "9DOF". This only represents the number of sensor channels that are provided - in the 6050 sense, this is 3 axes on the gyroscope and 3 axes on the accelerometer. The 9150 adds another 3 axes for the magnetometer. Other sensors add a pressure sensor and claim "10DOF"! This has nothing to do with true "degrees of freedom" and motion/movement capturing, and these enhanced sensors still cannot deliver truly accurate 6DOF to the user experience.

TAGS: 3DOF, 6DOF

There certainly is!

Look in the downloads section of the website - please make sure you choose the correct guide for your device. If you are using an MPU-6050 gyro (without magnetometer) the instructions are different for those using MPU-9150 (magnetometer) equipped devices. Likewise, the EDTracker Pro has it's own user guide.

Obviously, having to turn your head 180 degrees in real life to see behind you in the game would not be sensible - you wouldn't be able to keep your eyes on your screen for starters! So the software provided allows you to set a scaling factor - a ratio of your physical head movement to your virtual head movement. This means that in practise you have to move your head far less to effect the same movement in-game. There is no single setting that suits everyone as it depends greatly on screen size, distance from screen, angle of vision and personal preference. In reality, most people end up moving their head no more than about 30 degrees off-centre.

As a result, we've had no-one report any issues of neck fatigue.

The physical device is just a USB HID device so yes, it works fine on Apple OS X as a joystick input device.

The only issue is that the current software UI used to calibrate and configure the EDTracker is Windows only. This means in order to set up and calibrate your device, or to flash it in the future, you will need to perform this step on a Windows machine (or under Boot Camp).

Well, we don't get too fussed about it, but we call it "edd tracker" (ie. rhymes with head tracker) rather than "ee dee tracker". Pronounce it how you like ;)

The DIY EDTracker is for people who want to build it themselves. It's Arduino-based, open source and cheap but you'll need to be up for a bit of soldering.

EDTracker Pro came about because we were getting lots of requests to build EDTrackers for people - to the point where it was just getting too much work. So Pro is a dedicated circuit design made by us. The PCBs are fabricated for us, so the Pro is a much more dedicated, professional solution - but it's not open source. It's a ready-built unit sold by us for those who just want to get their hands on a working device with the minimum of fuss.

This article sums it up.