外文翻譯--基于ds18b20分組方式溫度測(cè)試系統(tǒng)設(shè)計(jì)

1、畢業(yè)設(shè)計(jì)外文資料翻譯 畢業(yè)設(shè)計(jì)外文資料翻譯外文出處： 2007 Second IEEE Conference on Industrial Electronics and Applications學(xué) 院： 信息工程 系：電子信息工程專 業(yè)： 電子信息工程 班 級(jí)： 學(xué) 號(hào)：

2、 學(xué)生姓名： TH and TL).DS18B20 communicates with the microprocessor by the single bus port and the test range of DS18B20 is from -55 centigrade to +125 centigrade, and the inc

3、remental value is 0.5 centigrade. The temperature can be changed into figures within 720ms and each DS18B20 has the sole 64 figures serial number. The specific content is revealed as Fig 1: There are two 8 figures stor

4、ages (No.0 and No.1) for storing temperature value in DS18B20. No.0 storage stores complement of the temperature value, and No.1 stores symbols of the temperature value. The user can define non-volatile temperature alar

5、ms sets and distinguish the alarms search order and seek the component temperature alarms state outside the scheduled limit. There are two alternative ways of power supply: Signal bus high-level borrow power is adopted,

6、 or the +5v power supply externally is adopted directly.Fig 1 DS18B20 64bit ROMⅢ. APPLICATION THE GROUPING TEST METHODThis paper illustrates the grouping method with the interface of DS18B20 and 89C52. Assuming the amoun

7、t of the buses on P1 port is 4 and the temperature test system needs 100 DS18B20 sensors, which can be distributed equally to the 4 I/O lines. If the number of sensors cannot be divided by the number of buses even, the

8、number disparity of sensorson buses is no more than one, which can be handled while reading numbers. The power is supplied externally. Owning to the synchronistic conversion in each DS18B20, the intense current is needed

9、, and the signal bus cannot be used for the power supply, otherwise the system cannot work in order. The schematic circuit is shown as Fig 2 (the DS18B20 signal buses of the same group are hung on some buses of P1 port

10、). When read and write the DS18B20, the strict schedule must be kept. First a reversion pulse is sent to all DS18B20. After the reversion, Skip ROM order is sent to each circuitsimultaneously from the I/O port, and the

11、conversion order is sent, then all sensors begin transform. After the conversion, Match Rom order is sent to each circuit simultaneously, and 64 bits serial number is sent. DS18B20 is selected for each group, and Scrat

12、ch Pad data is read. Finally the data is transformed. The data of serial-read is transformed into the actual temperature value. One alternate test is finished after the DS18B20 temperature data is read completely by the