整理英文传感器.docx

1、整理英文传感器毕业设计中英文翻译学生姓名： 学号： 微电子学学 院： 鲍爱达专 业： 指导教师： 2011年 6 月ELECTRONICS2004 22-24 September, Sozopol, BULGARIAMEASUREMENT OF TEMPERATURE AND HUMIDITY USINGSHT11/71 INTELLIGENT SENSORAssist. Prof. Grisha Spasov, PhD, BSc Nikolay KakanakovDepartment of Computer Systems, Technical University branch Plovd

2、iv, 25, “TzankoDjustabanov” Str., 4000 Plovdiv, Bulgaria, +359 32 659 576, e-mail: gvstu-plovdiv.bg,kakanaktu-plovdiv.bgKeywords: temperature and humidity measurements, intelligent sensors,distributed automation and controlThe paper discusses the advantages of intelligent sensors. It presents an SHT

3、11/71 temperatureand humidity combined sensor from Sensirion. This sensor is ideal for developing distributedembedded systems for monitoring environmental parameters.An example application using this sensor is added to present SHT11/71 in real workingcondition. The application is distributed system

4、for monitoring temperature and humidity. It uses amicrocontroller with integrated web server to organize the communication and management ofsensors. This application is realized and tested.1. INTRODUCTIONMeasurement and control of temperature and relative humidity has significantappliance in industr

5、y, science, healthcare agriculture and controlling technologicalprocesses. These two environmental parameters strongly influence each other and itis critical in some application to measure them in parallel. Using modern technologiesit is possible to combine temperature measurement element, humidity

6、measurementelement, amplifier, ADC, digital interface, calibration memory and CRC calculationlogic in a single chip with very small size 1,3.Using intelligent sensors of this kind can shorten the development time and cost.Integrating ADC and amplifier into sensors chip allow developers to optimize s

7、ensorelements for accuracy and long-term stability. And that is not all integrating digitalinterface logic simplifies connectivity and management of sensors. These advantagescan reduce whole time-to-market time and even price 1,3.In presented paper we use SHT11/71 intelligent sensor from Sensirion a

8、s anexample and present its advantages and measurement procedures. An exampleapplication is also presented to demonstrate its work in real conditions. Thisapplication is realized and tested.2. INTELIGENT SENSORS SHT11/71SHT11/71 is a single chip relative humidity and temperature multi sensor modulec

9、omprising a calibrated digital output. The device includes a capacitive polymersensing element for relative humidity and a bandgap temperature sensor. Both areseamlessly coupled to a 14bit ADC and a serial interface circuit on the same chip.This results in high signal quality, a fast response time a

10、nd insensitivity to externaldisturbances (EMC). Each SHT11/71 is individually calibrated and calibrationcoefficients are programmed into the OTP memory. The 2-wire serial interface andinternal voltage regulation allow easy and fast system integration 1.ELECTRONICS2004 22-24 September, Sozopol, BULGA

11、RIAThe SHT11/71 is shown on fig. 1 1.Combining temperature and humidity sensing elements in single unit enablesprecise determination of dewpoint, without incurring errors due to temperaturegradients between elements. The signal amplification near the sensor allows thepolymer layers to be optimized n

12、ot for signal strengths, but rather for long-termstability. Performing analog-to-digital conversion “in place” makes the signalextremely insensitive to noise. A checksum generated by the chip itself is used foradditional reliability. The calibration data loaded on the chip memory guarantees thathumi

13、dity sensors have identical specifications and thus they are 100% replaceable1.Some of the advanced functions of the SHT11/71 are available trough the statusregister. Some of them are: internal heating element; regulation of measurementresolution to optimize for precision or for fast response; End-O

14、f-Battery (EOB)detection (low voltage detection). Status register size is 8 bits but only four of themare used 1.SHT11/71 can be connected directly to any microcontroller by means of thedigital 2-wire interface. This interface is optimized for sensor readout and powerconsumption and is not compatibl

15、e with I2C interfaces 1. (See fig. 2)Two wires are used to transfer serial clock (SCK) and data (DATA). The SCK isused to synchronize the communication between a microcontroller and theSHT11/71. Since the interface consists of fully static logic there is no minimumfrequency. The DATA tristate pin is

16、 used to transfer data in and out of the module. Itchanges after the falling edge and is valid on the rising edge of the SCK. During thetransmission the DATA line must remain stable while SCK is high 1.Signals over the two lines during an example transmission are shown on fig. 3 1.ELECTRONICS2004 22-24 S