外文翻譯---一種基于ds18b20的溫度探測系統(tǒng)-文庫吧資料
2025-01-24 14:58本頁面
【正文】 d, so the cycle of alternate test gets longer. In this paper, a new method that DS18B20 are rationally grouped is presented, and some measures are taken in software。 as a result, the speed of alternate test advances distinctly. Key words DS18B20 Group, temperature test, time spent on the alternate test.1. INTRODUCTION As the simple structure, convenient installment, low loss and wide range of temperature test, DS18B20 temperature test sensors are applied to the fields which need the multipoint temperature test, such as the chemical industry, the grain, the environment supervision and so on. Because of the adoption of one bus in the DS18B20 multipoint temperature test system, all DS18B20 are hung on one bus, and then the temperature conversion value of each test point is read by turns. As the conversion value must be read after readingpin state for 8 times, and position and store data must be moved, so time spend much in reading one point of the data system by every time. If the temperature test system is largescaled, the system loss caused by it is rather much, and then the alternate test speed of the system decreases obviously, which influences the efficiency of the multipoint temperature test system seriously. In this paper, DS18B20 are hung on some I/O buses by grouping DS18B20 evenly, and the conversion temperature data is obtained by reading the state of DS18B20, then the system loss decreases and the alternate test speed increases obviously, which won’t influence the precision and the reliability of the conversion. A set of multipoint temperature test of artificial environment laboratory is achieved in this paper, which increases the test efficiency of the former system.2. CHARACTERISTICS OF DS18B20 DS18B20 is the single bus digital temperature sensor from American Dallas Company. DS18B20 is consisted of the 64 figures ROM engraved by laser, the temperature sensitivity ponent, nonvolatile temperature alarms trigger (Device TH and TL).DS18B20 municates with the microprocessor by the single bus port and the test range of DS18B20 is from 55 centigrade to +125 centigrade, and the incremental value is centigrade. The temperature can be changed into figures within 720ms and each DS18B20 has the sole 64 figures serial number.Fig 1 DS18B20 64bit ROMThe specific content is revealed as Fig 1: There are two 8 figures storages ( and ) for storing temperature value in DS18B20. storage stores plement of the temperature value, and stores symbols of the temperature value. The user can define nonvolatile temperature alarms sets and distinguish the alarms search order and seek the ponent temperature alarms state o
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