28029 Parallax Inc, 28029 Datasheet - Page 7

• Manufacturer Part Number: 28029
• Description: KIT PARTS SMART SENSORS W/TEXT
• Manufacturer: Parallax Inc

Specifications of 28029

• Accessory Type: Parts Kit
• Product: Microcontroller Accessories
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: BASIC Stamp® or Javelin Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 28029PAR

Preface
INTRODUCTION AND AUTHOR'S NOTE
The first time I saw the term "smart sensor" was in Tracy Allen's Applied Sensors text
(then known as Earth Measurements). Tracy aptly applied this term to the DS1620 digital
thermometer, which has built-in electronics that simplify microcontroller temperature
measurements. In addition, it can remember settings it receives from a microcontroller
and even function on its own as a thermostat controller.
In contrast to smart sensors, primitive sensors are devices or materials that have some
electrical property that changes with some physical phenomenon. An example of a
primitive sensor from What's a Microcontroller? is the cadmium sulfide photoresistor.
Its resistance changes with light intensity.
microcontroller light measurements are possible. Other examples of common primitive
sensors are current/voltage output temperature sensors, microphone transducers, and even
the potentiometer, which is a rotational position sensor.
Inside every smart sensor is one or more primitive sensors and support circuitry. The
thing that makes a smart sensor "smart" is the additional, built-in electronics. The
electronics make these sensors able to do one or more of the following:
During my first encounter with a smart sensor, I thought to myself, "Wow, an entire kit
full of these smart sensors with a book could be REALLY interesting! I sure hope
somebody does a kit and book like that soon..." Little did I know that "soon" would end
up being almost six years later, and that "somebody" would turn out to be me. And if one
of my bosses was to have told me back then that the kit would contain an accelerometer,
ultrasonic rangefinder, digital compass, and a serial LCD for mobile measurements, I
might just have come completely unglued. Since it was only recently possible for us to
•
•
•
•
•
Pre-process their measured values into meaningful quantities
Communicate their measurements with digital signals and communication
protocols
Orchestrate the actions of primitive circuits and sensors to "take" measurements
Make decisions and initiate action based on sensed conditions, independent of a
microcontroller
Remember calibration or configuration settings
With the right circuit and program,
Preface · Page iii