數字溫濕度計的設計畢業論文-資料下載頁

　　

【正文】 OD=0x02。//中斷初始化TH0=0x06。TL0=0x06。TR0=1。ET0=1。EA=1。while(1){error=0。error+=s_measure((unsigned char*)amp。,amp。checksum,HUMI)。error+=s_measure((unsigned char*)amp。,amp。checksum,TEMP)。if(error!=0)//如果 error=1,從新復位 {s_connectionreset()。}else{=(float)。=(float)。46calc_sth11(amp。,amp。)。display(,)。s_connectionreset()。}for(i=0。i40000。i++)。s_connectionreset()。}}外文資料DS1722 Digital Thermometer47With scientific and technological progress and development of the types of temperature sensors increasingly wide range of application of the increasingly widespread, and the beginning analog toward digital, singlebus, dualbus and bus3 direction. And the number of temperature sensors because they apply to all microprocessor interface consisting of automatic temperature control system simulation can be overe sensor and microprocessor interface need signal conditioning circuit and A / D converters advantages of the drawbacks, has been widely used in industrial control, electronic transducers, medical equipment and other temperature control system. Among them, which are more representative of a digital temperature sensor DS18B20, MAX6575, the DS1722, MAX6636 other. This paper introduces the DS1722 digital temperature sensor characteristics, the use of the method and its timing. Internal structure and other relevant content. FEATURES:Temperature measurements require no external ponents。Measures temperatures from 55176。C to +120176。C. Fahrenheit equivalent is 67176。F to +248176。F。Thermometer accuracy is 177。176。C。Thermometer resolution is configurable from 8 to 12 bits (176。C to 176。C　resolution)。Data is read from/written to via a Motorola Serial Peripheral Interface (SPI) or standard 3wire serial interface。Wide analog power supply range ( )。Separate digital supply allows for logic。Available in an 8pin SOIC (150 mil), 8pin USOP, and flip chip package。PIN ASSIGNMENTFIGURE 1 PIN ASSIGNMENTPIN DESCRIPTION:SERMODE Serial Interface Mode.CE Chip Enable.SCLK Serial Clock.GND – Ground.48VDDA Analog Supply Voltage.SDO Serial Data Out.SDI Serial Data In.VDDD Digital Supply Voltage.DESCRIPTION:The DS1722 Digital Thermometer and Thermostat with SPI/3Wire Interface provides temperature readings which indicate the temperature of the device. No additional ponents are required。 the device is truly a temperaturetodigital converter. Temperature readings are municated from the DS1722 over a Motorola SPI interface or a standard 3wire serial interface. The choice of interface standard is selectable by the user. For applications that require greater temperature resolution, the user can adjust the readout resolution from 8 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be detected quickly.For application flexibility, the DS1722 features a wide analog supply rail of . A separate digital supply allows a range of to . The DS1722 is available in an 8pin SOIC (150mil), 8pin USOP, and flip chip package.Applications for the DS1722 include personal puters/servers/workstations, cellular telephones, office equipment, or any thermallysensitive system.OVERVIEW:A block diagram of the DS1722 is shown in Figure 2. The DS1722 consists of four major ponents:1. Precision temperature sensor.2. Analogtodigital converter.3. SPI/3wire interface electronics.4. Data registers.The factorycalibrated temperature sensor requires no external ponents. The DS1722 is in a power conserving shutdown state upon powerup. After powerup, the user may alter the configuration register to place the device in a continuous temperature conversion mode or in a oneshot conversion mode. In the 49continuous conversion mode, the DS1722 continuously converts the temperature and stores the result in the temperature register. As conversions are performed in the background, reading the temperature register does not affect the conversion in progress. In the oneshot temperature conversion mode, the DS1722 will perform one temperature conversion, store the result in the temperature register, and then eturn to the shutdown state. This conversion mode is ideal for power sensitive applications. More information on the configuration register is contained in the “OPERATIONProgramming” section. The temperature conversion results will have a default resolution of 9 bits. In applications where small incremental temperature changes are critical, the user can change the conversion resolution from 9 bits to 8, 10, 11, or 12. This is acplished by programming the configuration register. Each additional bit of resolution approximately doubles the conversion time. The DS1722 can municate using either a Motorola Serial Peripheral Interface (SPI) or standard 3wire interface. The user can select either munication standard through the SERMODE pin, tying it to VDDD for SPI and to ground for 3wire. The device contains both an analog supply voltage and a digital supply voltage (VDDA and VDDD, respectively). The analog supply powers the device for operation while the digital supply provides the top rails for the digital inputs and outputs. The DS1722 was designed to be LogicReady.50DS1722 FUNCTIONAL BLOCK DIAGRAM Figure 2OPERATIONMeasuring Temperature:The core of DS1722 functionality is its directtodigital temperature sensor. The DS1722 measures temperature through the use of an onchip temperature measurement technique with an operating range from 55176。　to +120176。C. The device powers up in a powerconserving shutdown mode. After powerup, the DS1722 may be placed in a continuous conversion mode or in a oneshot conversion mode. In the continuous conversion mode, the device continuously putes the temperature and stores the most recent result in the temperature register at addresses 01h (LSB) and 02h (MSB).