06-02-2012, 03:45 PM
ALCOHOL DETECTOR
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INTRODUCTION:
Objective: The main aim of this embedded application is to design a alcohol detector using RF Communication and AT89c51 Programmable controller.
DESCRIPTION OF THE PROJECT
This application is in the area of embedded systems.
An embedded system is some combination of computer hardware and software, either fixed in capability or programmable, that is specifically designed for a particular function
Since the embedded system is dedicated to specific tasks, design engineers can optimize it reducing the size and cost of the product and increasing the reliability and performance. Embedded systems are controlled by one or more main processing cores that are typically either a microcontroller or a digital signal processor (DSP). Embedded systems control many devices in common use today.
2.2 HT12E:
Features:
_ Operating voltage
_ 2.4V~5V for the HT12A
_ 2.4V~12V for the HT12E
_ Low power and high noise immunity CMOS technology
_ Low standby current: 0.1_A (typ.) at VDD=5V
_ HT12A with a 38kHz carrier for infrared transmission medium
_ Minimum transmission word
_ Four words for the HT12E
_ One word for the HT12A
_ Built-in oscillator needs only 5% resistor
_ Data code has positive polarity
_ Minimal external components
_ Pair with Holtek_s 212 series of decoders
_ 18-pin DIP, 20-pin SOP package
Applications
_ Burglar alarm system
_ Smoke and fire alarm system
_ Garage door controllers
_ Car door controllers
_ Car alarm system
_ Security system
_ Cordless telephones
_ Other remote control systems
