How Motion-Activated Screwdrivers Work

Many previously established power screwdriver technologies are integrated into the GYRO. The GYRO is meant to be a lightweight, portable and compact tool that can sink its teeth into even the most inaccessible screws in your home. As such, it comes with a light-duty 4-volt Lithium-ion battery pack. Unlike some other rechargeable batteries, you can energize the pack whenever and however you like without worry about battery memory problems.

And the company says the pack will hold its charge for roughly a year and a half, which speaks to the GYRO's purpose of occasional use. There's no battery level indicator whatsoever, though. When the power pack runs low, the device just stops working and an LED blinks a power-hungry distress signal.

In other words, you won't be doing hours of work with this tool. It's meant to help you tighten (or loosen) those sneaky, problematic screws that lurk in every house. To that end, it also has a tiny LED near the business end that illuminates your work area.

Black & Decker throws in two standard screw driving bits with each GYRO. You also receive a two-year warranty that covers any defects.

To use GYRO, you grip differently than most screwdrivers. The pistol-like handle end of GYRO flattens into a smooth, wide surface that settles into the palm of your hand. That big surface is actually one large button, called the motion control activator, and because you'll be pressing into the screw head each time you work, you'll hardly notice it. But unless that activator is depressed, the motor won't work.

In addition to the activator, Black & Decker built in a 45-second shutoff timer. It protects against accidental battery usage in case the motion activator gets jammed against that roll of duct tape in your junk drawer.

Those specs make up the backbone of the GYRO. On the next page, we'll drill down into the details of what makes this device unique to the realm of power tools.

In the GYRO, the gyroscope is obviously the spotlight attraction.

When you press the activator button, the gyroscope works in tandem with computer chips to determine where the unit is exactly in space. Then GYRO can detect and measure any changes to its orientation, which it understands as a command to engage the motor.

As for the gyroscope itself, it's an InvenSense ISZ-650, which is a Z-axis integrated MEMS (microelectromechanical systems) gyroscope that's meant to be resistant to the kind of abuse that all power tools face. They gyroscope chip is tiny, at only 4 by 5 by 1.2 millimeters (0.15 by 0.2 by 0.05 inches).

Gyroscopes can be multiple-axis devices -- that is, they can detect movement in any direction. This particular gyroscope, however, is configured primarily to pick up movement along the Z-axis, which in this case is the axis that's parallel to the motor shaft.

So when you engage the motion activator button, the gyroscope and computer chips take a snapshot of the screwdriver's position -- a so-called position zero. As you twist, the gyroscope and rate sensor capture and send angular velocity data to a 16-bit microcontroller. The farther you twist (measured by degrees), the farther and faster the microprocessor commands the electric motor to turn.

One thing about gyroscopes is that they often require a little minor maintenance. GYRO normally completes this calibration process automatically without you even knowing about it. Once in a while, though, you may notice that the directional control isn't working as exactly as you'd like. In that case, you can re-calibrate GYRO by pressing the button and letting it lie undisturbed on flat surface for five seconds. Just like that, your gyroscope -- and your GYRO -- should once again perfectly follow your hand motions.

The gyroscope might sound like a delicate piece of equipment, but in terms of toughness, the company says that this product will absorb the same kind of abuse as any of its other tools.

That means this revolutionary little screwdriver has enough power and durability to last for years. Not bad for a device that's sensitive enough to pick up on your body language.