數(shù)字溫度傳感器外文翻譯6

1、<p><b>　　英文參考資料</b></p><p>　　The DS18B20 Digital Thermometer provides 9 to 12–bit centigrade temperature measurements and has an alarm function with nonvolatile user-programmable upper and l

2、ower trigger points. The DS18B20 communicates over a 1-Wire bus that by definition requires only one data line (and ground) for communication with a central microprocessor. It has an operating temperature range of –55&

3、#176;C to +125°C and is accurate to 0.5 C over the range of –10°C to +85°C. In addition, the DS18B20 can derive power direc</p><p>　　Each DS18B20 has a unique 64-bit serial code, which allows

4、 multiple DS18B20s to function on the same 1–wire bus; thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HVAC env

5、ironmental controls, temperature monitoring systems inside buildings, equipment or machinery, and process monitoring and control systems.</p><p><b>　　OVERVIEW</b></p><p>　　The 64-bit

6、 ROM stores the device’s unique serial code. The scratchpad memory contains the 2-byte temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad provides access to the 1

7、-byte upper and lower alarm trigger registers (T and T ), and the 1-byte configuration H L register. The configuration register allows the user to set the resolution of the temperature-to-digital conversion to 9, 10, 11,

8、 or 12 bits. The T, T and configuration registers </p><p>　　Another feature of the DS18B20 is the ability to operate without an external power supply. Power is instead supplied through the 1-Wire pull up res

9、istor via the DQ pin when the bus is high. The high bus signal also charges an internal capacitor (C ), which then supplies power to the device when the bus is PP low. This method of deriving power from the 1-Wire bus is

10、 referred to as “parasite power.” As an alternative, the DS18B20 may also be powered by an external supply on VDD</p><p>　　OPERATION — MEASURING TEMPERATURE</p><p>　　The core functionality of th

11、e DS18B20 is its direct-to-digital temperature sensor. The resolution of the temperature sensor is user-configurable to 9, 10, 11, or 12 bits, corresponding to increments of 0.5 C, 0.25 C, 0.125 C, and 0.0625 C, respecti

12、vely. The default resolution at power-up is 12-bit. The DS18B20 powers-up in a low-power idle state; to initiate a temperature measurement and A-to-D conversion, the master must issue a Convert T [44h] command. Following

13、 the conversion, the resulting t</p><p>　　POWERING THE DS18B20</p><p>　　The DS18B20 can be powered by an external supply on the VDD pin, or it can operate in “parasite power” mode, which allows

14、the DS18B20 to function without a local external supply. Parasite power is very useful for applications that require remote temperature sensing or that are very space constrained. DS18B20’s parasite-power control circui

15、try, which “steals” power from the 1-Wire bus via the DQ pin when the bus is high. The stolen charge powers the DS18B20 while the bus is high, and some of the</p><p>　　DS18B20數(shù)字溫度傳感器提供9-12位的分辨率而且還有一種報(bào)警功能，它內(nèi)部

16、有非易失的用戶(hù)可編程的單元用來(lái)設(shè)置溫度的上限和下限。DS18B20通過(guò)一總線(xiàn)技術(shù)來(lái)通信，只需要一根數(shù)據(jù)線(xiàn)就可以與單片機(jī)進(jìn)行通信。它可以檢測(cè)的范圍是-55°C 到+125°C，而且在–10°C 到+85°C.范圍內(nèi)它的精確度是0.5 C。此外DS18B20能夠通過(guò)數(shù)據(jù)線(xiàn)驅(qū)動(dòng)，也就是通過(guò)數(shù)據(jù)線(xiàn)傳遞能量，這樣就可以避免另外設(shè)計(jì)電源電路和電源線(xiàn)了。</p><p>　　每個(gè)DS18

17、B20都有唯一的64位序列號(hào)?？梢园讯鄠€(gè)DS18B20連接在一根數(shù)據(jù)線(xiàn)上，通過(guò)這個(gè)序列號(hào)可以操作響應(yīng)的溫度傳感器。這樣很容易就可以實(shí)現(xiàn)一個(gè)單片機(jī)控制多個(gè)溫度傳感器。HVAC環(huán)境控制器和溫度控制器系統(tǒng)都應(yīng)用該傳感器實(shí)現(xiàn)了很好的功能。</p><p>　　正如上面所說(shuō)的64位的ROM中存儲(chǔ)這溫度傳感器的唯一序列號(hào)。RAM中存儲(chǔ)著兩個(gè)字節(jié)的溫度值，這兩個(gè)字節(jié)的數(shù)據(jù)將來(lái)要通過(guò)數(shù)據(jù)總線(xiàn)傳到單片機(jī)那里。此外，暫時(shí)寄存器還和一

18、個(gè)字節(jié)的上限、下限寄存器相連，同時(shí)也和一個(gè)字節(jié)的配置字相連。這個(gè)配置寄存器允許用戶(hù)設(shè)置溫度傳感器的分辨率在9、10、11、12這四個(gè)數(shù)之間。上下限寄存器和配置寄存器都是用非可易失性的材料做的，所以在掉電之后也不會(huì)丟失數(shù)據(jù)。該溫度傳感器通過(guò)達(dá)拉斯公司獨(dú)特的單總線(xiàn)技術(shù)通過(guò)一根數(shù)據(jù)線(xiàn)實(shí)現(xiàn)和單片機(jī)的交互。數(shù)據(jù)線(xiàn)也就是總線(xiàn)需要一個(gè)比較小的上拉電阻，因?yàn)樗械男盘?hào)都是通過(guò)總線(xiàn)來(lái)傳輸?shù)?，這根總線(xiàn)有三種狀態(tài)，在單總線(xiàn)系統(tǒng)中，單片機(jī)也就是主設(shè)備通過(guò)溫度傳

19、感器的唯一的64位碼來(lái)識(shí)別和定位傳感器。因?yàn)槊總€(gè)但單總線(xiàn)設(shè)備都有一個(gè)唯一的64位的識(shí)別碼，所以主機(jī)可以連接的從設(shè)備理論上說(shuō)是沒(méi)有數(shù)量限制的。</p><p>　　DS18B20另一個(gè)特征是它不需要額外的供電系統(tǒng)。電源是通過(guò)單總線(xiàn)系統(tǒng)中的DQ管腳傳入的，當(dāng)這個(gè)管腳是高電壓時(shí)供電。而當(dāng)DQ為低電平時(shí)，傳感器就不工作了？當(dāng)然不是了，在溫度傳感器的內(nèi)部有一個(gè)電容，當(dāng)DQ為高電平時(shí)充電，當(dāng)DQ為低電平時(shí)放電，放出來(lái)的電給傳

20、感器供電。當(dāng)然如果不只使用溫度傳感器的一個(gè)管腳的話(huà)，也可以由額外供電，也就是通過(guò)傳感器的VDD管腳，給它提供+5V的電壓就可以使DS18B20正常工作了。</p><p>　　DS18B20的核心部位是其可以直接將外界溫度信息直接轉(zhuǎn)換成數(shù)字信號(hào)的溫度傳感器。該溫度傳感器是可以用戶(hù)設(shè)置的，有9位、10位、11位和12位的分辨率，分別對(duì)應(yīng)0.5 C, 0.25 C, 0.125 C,和 0.0625 C,的增量，也就

21、是說(shuō)數(shù)字每增加一溫度增加的值。默認(rèn)情況下是設(shè)置成12位模式的。為了能夠初始化溫度傳感器和使其內(nèi)部的模數(shù)轉(zhuǎn)換電路工作，主設(shè)備也就是單片機(jī)需要給DS18B20發(fā)出轉(zhuǎn)換命令（即向DS18B20傳送44H）。在傳感器接收到命令之后，并作出反應(yīng)后，溫度值被存儲(chǔ)在溫度傳感器內(nèi)部的兩字節(jié)的溫度寄存器中，這兩個(gè)字節(jié)在斷電后會(huì)丟失數(shù)據(jù)，然后溫度傳感器恢復(fù)等待命令狀態(tài)（即空閑狀態(tài)）。如果DS18B20是由額外電源供電的話(huà)，那么DS18B20會(huì)在正在轉(zhuǎn)換時(shí)保

22、持低電平，而完成轉(zhuǎn)換之后就會(huì)保持高電平了。如果DS18B20是寄生供電的話(huà)，由于在傳感器轉(zhuǎn)換期間需要比較大量的電能，所以就不能夠支持上訴的功能了。溫度傳感器中要輸出的溫度數(shù)據(jù)單位是按照攝氏溫度來(lái)的，如果要轉(zhuǎn)換成華氏溫度的話(huà)就需要用戶(hù)自己做一個(gè)轉(zhuǎn)換表了。溫度值在DS18B20中是以?xún)勺止?jié)的補(bǔ)碼形式存儲(chǔ)在溫度傳感器中的。符</p><p>　　DS18B20既可以通過(guò)VDD管腳來(lái)提供額外的電源，也可以通過(guò)寄生電源的方

23、式來(lái)為其自身供電。寄生電源對(duì)于要求要求遠(yuǎn)距離溫度檢測(cè)的應(yīng)用或者是那些非常惡劣的環(huán)境下的一個(gè)用來(lái)說(shuō)是非常合適的。溫度傳感器的寄生電源是在DQ管腳為高電壓的時(shí)候存儲(chǔ)電量來(lái)為以后DQ為低的時(shí)候供電。而且當(dāng)傳感器工作在寄生電源的模式下時(shí)，VDD管腳一定要接地，不然就會(huì)不能判定究竟是在什么模式在工作了。當(dāng)DS18B20工作在寄生電源模式時(shí)，單總線(xiàn)和CPP能夠?yàn)槠浯蟛糠值牟僮魈峁┳銐虻碾娫?。而?dāng)DS18B20進(jìn)行溫度轉(zhuǎn)換或?qū)?shù)據(jù)從易失性存儲(chǔ)介質(zhì)中拷