Designing Gestural Interfaces

STEP TO ACTIVATE

WHAT

A user steps (either deliberately or unknowingly) onto a designated spot that triggers an action.

USE WHEN

Use Step to Activate when other proximity detectors (sound, infrared cameras, etc.) would be impractical, or for actions that would naturally be delivered by the feet (stepping, dancing, etc.).

WHY

This pattern is useful for alternative controls when the hands are occupied or for controls in low places where it would be difficult to reach with the hands.

HOW

Step to Activate typically requires a pressure sensor placed inside or beneath a flat object, sometimes to protect the sensor from hard stomps or presses.

EXAMPLES

Figure 4-19. One of the many incarnations of Dance Dance Revolution, where players follow on-screen cues to step in various directions quickly to play the game (and thus to dance). Courtesy Warren Rohner.

Figure 4-20. The X-Keys Foot Pedal can be programmed to perform common computer functions with three different locations that can be used for Step to Activate. Courtesy PI Engineering.

Figure 4-21. The Rectangular Sensor Can is an example of Step to Activate that uses an infrared sensor instead of a pressure sensor. When a user slips his foot into the recession ...