By John Blyler
Both the sensor and wireless market continue to be strong growth areas in the electronics industry, especially the mobile segment. This growth is attributed in large measure to the cost-effective availability of sensors based on microelectromechanical systems (MEMS) and RF components.
Sensors and wireless technology always have been important subsystems in the design of most mobile electronics. Today, however, these technologies have become so pervasive as to define what is meant by “a system.”
Mobile electronics—from smartphones and tablets to smart robots—are no longer distinguished by their processors or RTOSes, but by the type of sensors and wireless features that they support.
To get a sense of the changes taking way, consider the Segway. When first introduced, the Segway was a marvel of balance and control. Digital signal processors, microcontrollers, sensors and motors keep the personal transport upright during motion. Gyroscopes and level-detecting sensors—mainly accelerometers—detect shifts in passenger weight to both control the speed and direction of the Segway.
Thanks to the area, power and performance scaling achieved by the semiconductor industry, today’s Segway has found many new applications. The smaller size of high-performance and ultra-low-power electronics and motors has made Segway technology ideal for the robotics industry.
So affordable have these constituent subsystems become that Segway-like robots are being used in engineering course at institutions like the University of Illinois. The Segbot is part of several inverted pendulum projects in the U of I Control Systems Labs. Like their big brothers, these miniature robots use MEMS-based accelerometers and rate gyroscopes to determine and maintain balance of the device. The sensors give the robot its amazing stability. As with it big brethren, the Segbot relies on TI DSPs embedded in a microcontroller to perform the necessary the necessary positioning and balancing algorithms.
The basic design of these robotic systems is not new; nor is the use of sensors to control the motion or position of the robots. What are new are the tiny sizes, ultra-low power and fast performance of today’s sensors and associated signal conditioning components.
Aside from new technology in the control system, there other new features that have become synonymous with mobile systems is the wireless connection. For example, the Segbot is remotely controlled by a wireless watch – namely, the Texas Instruments’ eZ430-Chronos Wireless Watch Development Tool. The watch is basically a motion-sensitive microcontroller development platform that uses a USB interface for coding and debugging of the embedded target system. Once programmed, a user moves his/her watch arm in various positions to control the Segbot. (Youtube video: “Segbot controlled with TI’s Chronos watch at ESC2011“)
Gesturing is a growing type of user interface, especially in the consumer market. Many applications are being developed for gesture-based interfaces that rely on camera and video systems (See Qualcomm Recognizes Importance of Gesture IP ). These applications, like the U of I Segbot, require high-performance DSPs to process sensor and video stream data. Unlike camera-based system, the Segbot requires only arm motions to wirelessly control motions on the target platform. The user can literally control the direction of the robot with a wave of their arm.
Yesterday’s vernacular of hardware and software has given way to a more functionally-based discussion. Systems designers should take note that it will be difficult to develop future electronics devices that don’t contain an array of sensors and wireless interfaces.