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How Motion-Activated Screwdrivers Work

Axis of Power
You won’t see the GYRO on construction sites anytime soon. It’s primarily designed for light duty around the house.
You won’t see the GYRO on construction sites anytime soon. It’s primarily designed for light duty around the house.
Courtesy Black & Decker

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.