Five cool things you can do with an accelerometer—and the g’s you’ll need to detect

Freescale has been big in MEMs-based accelerometers for the automobile market for a while, and they seem to be moving that technology down to a lower price point where it plays in consumer goods. In talking with Dan Larson, proximity sensor product line manager for Freescale, some neat features can be added to designs when you include an accelerometer. For instance:

Cellphones: The Apple iPhone will reportedly have an accelerometer to detect free-fall and turn itself off before impact, and will also be to switch from portrait to landscape camera mode. You can also use a finger tap to turn a phone on or off or place it into another mode, such as speaker-phone. And as cell phones pick up GPS capability, you can use the accelerometer to add dead-reckoning and fine-tune the phone’s position to a couple of feet.

Notebook computers: Freefall detection again comes in handy because the notebook can park the head on its hard-drive down when an impact is imminent. You’ll still have to deal with a busted LCD, but at least your data can be retrieved.

Handheld game controllers: Nintendo’s Wii is a precursor of things to come, with bats, clubs, rackets – even swords – gaining the ability to communicate speed and direction. These already exist on high-end simulators – you’ve probably seen the ones for golf – but the prices for these will plummet and become ubiquitous.

Shipping: Tag a package with an accelerometer and now both you and FedEx know if it was ever dropped or jarred.

Running shoes: Measure stress on knees and joints based on a shoes “track record.” Also, include a pedometer in the shoes that’s far more accurate and easier to use than current pedometers.

Getting down to the nitty-gritty, here are the acceleration numbers you’ll need to handle for various applications:

1.5g: Freefall detection, accurate tilt compensation.

3g: Handheld motion detection for gaming controller

4g-6g-: Low vibration monitoring for shipping and handling, on up to higher shock readings

12g: Out-of-balance detection, pedometer

16g: Sports monitoring, robotics