# Experiments with the Apple Motion Sensor

You could also use this to create a crude inertial navigation system. Integrating the force measurements (with gravity mathematically subtracted) would give you the velocity of the powerbook. Integrating the velocity would give the position. Getting the correction factors might be tricky (one might even need to reference a temperature sensor to correct for thermal effects), but it would be cool to use a powerbook for navigation.

### Docked?

I use a stand to elevate my PowerBook when I'm working at my desk. In the stand, the computer is almost vertical, so it's easy to distinguish between "at the desk" and "on the lap" with the Y axis. Now if I could just think of some cron task that should only run when I'm at my desk...

### Mobile Dyno

G-force and distance traveled are all that is needed to make the calculations for a Dyno run. A simple stopwatch (automatic) and an input to mark 10ths of a mile (or xths of a mile) would give fairly accurate results.

### Mass

Thermal effects? What thermal effects?

All you should need for a VERY crude inertial nav system is the PowerBook's mass properties (center of mass, actual mass, distance of sensor from center of mass, etc) and orientation of the sensor to figure out some rough navigation data.

All the hard work is done - Apple gives you acceleration values in three axes!

I'd be curious to see how the sensor reacts to angular acceleration. If the laptop is spun around on a table, what does the sensor say?

As I'm sure we all know:
X(t) = Xi + Vx*t + Ax*t*t
Y(t) = Yi + Vy*t + Ay*t*t
Z(t) = Zi + Vz*t + Az*t*t

Peace,
Drew

### What Model?

What model first had this technology in it? Just curious as ti if this is a recent thing or if it has been around for a while. Also, This could have some real fun uses for applications. A game like the old "Marble Madness" for NES would be real cool. And I could easily see other uses for this...

### labyrinth

Another great gaming application for motion sensor input would be a laptop-based Labyrinth game... although it might be more intuitive on a machine with a tablet form factor.

### Re: Mobile Dyno

G-force and distance traveled are all that is needed to make the calculations for a Dyno run. A simple stopwatch (automatic) and an input to mark 10ths of a mile (or xths of a mile) would give fairly accurate results.

You only need g-force, weight of vehicle, and time calculation to do a dyno.

Technically you use g-force and weight of the vehicle to measure torque and as a function of time figure out how much work got done in a given amount of time, and you get horsepower.

### Motion Sensor + Camera

There are games for mobile phones where you need to balance a ball through a (virtual) maze (e.g. http://people.freenet.de/hskopp/wabbellab.html). While these games use the built-in camera of mobile phones, the PowerBooks could use the motion sensor.

Or, even better: Why not develop games that use both, the motion sensor and the built-in iSight (in the new G4 PB models)? A whole new dimension of gaming coming to a PowerBooks.

I agree that a tablet form factor would be even more intriguing...

### Security

Wouldn't it be great if the Apple Motion Sensor would be used for security?
When you leave your laptop, you could activate a program, which detects laptop-movement and trigger an alarm-sound. Great if working in busy places such as school and you need to walk to the other side of the room or something like that.

### [url=http://digg.com/apple/Ca

digg.com has an article on a bubble level widget that use this sensor. Maybe more programmers will take notice.

### The obvious...

The new MacBook MUST be able to do THIS:

http://www-structure.bio.purdue.edu/~bhebert/Cartoons/cartoons.htm

In Dilbert We Trust

### security

Check out iAlertU. Wehen the machine is armed and the motion sensor (adjustable) is triggered a loud alarm begins to sound and if your machine is equipped with iSight, it will take a snapshot of the perp. With newer versions you can have the snapshot sent to an e-mail. also check out Lojakmac or MacLojak.

### VRHMD

• Mount iBook on head. Upside down is probably safest, so the body of the laptop is on top of your head and the screen hangs down in front of your eyes. Attached to some kind of hat. With straps.
• In software, invert screen display vertically and divide it in half horizontally.
• Build eyepiece/s that separate/s left eye view from right eye view.