Bad accelerometer controls kill otherwise good games. I decided to try to do something about it. So I create an XNA GameComponent called AccelerometerInput. It’s still a beta project but you are welcome to try it, use it, modify it, etc. I’m releasing under the terms of the Microsoft Public License.

Important info:

First, it only supports tilt-style controls currently. I have not implemented motion-style controls yet (and make no promises as to when I might find time to do so).

Second, I commented it heavily so that you can (hopefully) understand what it is doing. Please read the comments and examine the sample game for a usage overview. There are configurable parameters which I encourage you to make use of (both by modifying the default values where your testing shows it to be appropriate and also by implementing a calibration mechanism in your game that lets the user adjust those configurable values based on his or her own circumstances).

Third, even with this code, accelerometer controls are still a fairly advanced topic area; you will likely find nothing but disappointment if you simply plunk this into some project without testing it on a device (or preferably on several devices).

Fourth, if you do try this code and find that something doesn’t work as expected on your phone, please let me know as I want to improve it and can only do so with your help. Let me know what phone model it is, what you tried doing, what you expected, and what result you had instead. I may or may not be able to incorporate it into the code, but I can let others know at the very least so that they can make appropriate modifications to their games (I’m hopeful that all phones are reasonably similar in their workings and require, at most, a slight calibration change, but I simply don’t know).

Fifth, although I’ll do my best to answer any questions you may have about it, I’m very busy with a number of things currently so it might take a little while. Please look through the code and examine the comments and sample game first before asking any questions. It’s likely that the answer is in there. If not, or if you just aren’t really sure, ask away.

Sixth, there are differences between a portrait-mode game and a landscape mode game (specifically in the appropriate default tilt adjustment for toward the user/away from the user calculations). This is documented and the default is set for landscape. If you use this for a portrait game, make the appropriate change (look for the TODO: comment in AccelerometerInput.cs).

Seventh, no provision whatsoever is made for disabling screen locking. It is up to you to implement that and to take appropriate measures to detect when the user has been idle for too long and timeout the game. That code is very game-specific. If you have questions about such matters, consult the relevant MSDN documentation and, if you still have questions, visit the App Hub forums and ask there. I answer questions there a lot and so I may even stumble across your question and answer it. But that’s a much better forum than the comments section here for questions of that sort so I would appreciate it if you asked idle detection-related questions there (or on some other suitable site that you may be more familiar and comfortable with).

Eighth, this is an XNA GameComponent intended for XNA-based games on WP7. A sufficiently knowledgeable Silverlight developer should have no problem adapting it for use in a Silverlight game or app. I may create a Silverlight version at some point myself. Right now I do not have the time, unfortunately.

Ok. Without further ado: http://www.bobtacoindustries.com/developers/utils/AccelerometerInput.zip

Have a great St. Patrick’s Day!