With the introduction of the Nintendo Wii recently an interest in motion sensing as a human interface device with computers has been peaked. It turns out that notebooks such as the Lenovo ThinkPad and Apple MacBook Pro have a built-in accelerometer that serves to protect the hard drive, but can also be used for gaming somewhat like you do on the Wii.
This article is inspired by a recent post at LenovoBlogs.com by Lenovo’s Matt Kohut regarding “alternative” use of the ThinkPad’s built-in motion sensor. It’s a great site, well worth bookmarking and checking out if you’re interested in notebooks and product design — you don’t have to be a ThinkPad fan to enjoy it.
I’ve owned a ThinkPad for years and have become accustomed to the built-in Active Protection System (APS) that detects sudden movement, such as a drop, and parks the head of the hard drive so that data is not destroyed. This is a very business like security feature, it’s used by Apple in their PowerBook and MacBook Pro line as well. Apple dubs the system “Sudden Motion Sensor”. At the core of both of these motion detection systems is an accelerometer, here’s what each company uses:
- IBM / Lenovo: Analog Devices model ADXL320 two-axis accelerometer chip, with dynamic range of +/- 5g and bandwidth upto 2.5kHz
- Apple: Kionix KXM52-1050 three-axis accelerometer chip, with dynamic range of +/- 2g and bandwidth up to 1.5KHz
Cutting to the chase though, business features tend to be a bit boring. What else could these motion sensor devices be used for? Like the motion sensor on the Wii, to play games of course!
Using the ThinkPad motion sensor to play games
Here I am playing Tux Racer via motion sensor control on my ThinkPad T43
Instead of re-writing everything that Matt wrote in his post, if you have a ThinkPad and want to play some games using the motion sensor just read over Matt’s post at LenovoBlogs.com. If you play the video above you’ll see that I downloaded the game Tux Racer and the necessary “hack” dll file to play the game and control Tux the penguin by tilting my ThinkPad T43 to guide the penguin. You might have to play around with the Active Protection System Properties to get the right calibration and sensitivity for playing, but it works and is very easy to get running!
Using the Apple PowerBook / MacBook Pro motion sensor to play games
Racing a car and using a flight simulator on the PowerBook via the motion sensor
Unfortunately using the accelerometer in a Mac is not so simple, the interface to the chip Apple uses is not public. Amit Singh, writer of the book Mac OS X Internals, has demonstrated the Motion Sensor can be used for gaming though and has an extensive website covering his research on this at KernelThread.com. Amit also has some videos on his site that are embedded in this article for ease of viewing that show using a PowerBook’s motion sensor to play car racing games, flight simulators and the pinball game Neverball. The Apple Sudden Motion Sensor is slightly more interesting than the one Lenovo uses because it offers a Z-axis (vertical) motion detection, meaning it can implement a “jump when I jump” type of control.
Neverball as played via motion sensor on the PowerBook
Alas, there is no site I can point you to for downloading a couple of files and getting motion sensing gaming up and running on your Mac, it’s a little more geeky than just that. If you read Amit’s book you might be able to understand and implement this ability though.
Are Motion Sensor Games the future for laptops?
No. Certainly not. Playing games while moving your laptop around vigorously is actually a bad idea and do it at your own risk. The hard drive could get jerked in the wrong manner and you might lose data or you could simply drop and break your laptop when waving it from side to side. There are however some interesting uses for the motion sensor outside of hard drive protection. For instance, the iAlertU application for a Mac allows you to “arm” your laptop motion sensor so if it detects movement the alarm screams:
Lenovo is using the accelerometer in the ThinkPad X60t Tablet so that the device detects which way up your holding it and rotates the screen so that it’s always the right way up:
And finally, using the Google Maps API, this engineering person wrote an application that allows you to tilt a Google Map and move around using the ThinkPad built-in motion sensor:
So long as the movement of the laptop is gentle, there’s not too much risk in doing any damage. It’s cool to see these types of things being done, and fun to play games using motion, but if you really want to get into that it’s best just to buy a Nintendo Wii 😉