FEATURES
Unique 1-Wire interface requires only one port pin for communication
Multidrop capability simplifies distributed temperature sensing applications
Requires no external components
Can be powered from data line. Power supply range is 3.0V to 5.5V
Zero standby power required
Measures temperatures from -55°C to +125°C. Fahrenheit equivalent is -67°F to +257°F
±0.5°C accuracy from -10°C to +85°C
thermometer resolution is programmable from 9 to 12 bits
Converts 12-bit temperature to digital word in 750 ms (max.)
User-definable, nonvolatile temperature alarm settings
Alarm search command identifies and addresses devices whose temperature is outside of programmed limits (temperature
alarm condition)
Applications include thermostatic controls, industrial systems, consumer products,
thermometers, or any thermally sensitive system
Digitemp Junior – An RS-232 Port-Powered Digital thermometer
Digitemp Jr. is a device that is designed to measure
and report ambient temperature. When connected to
an RS-232 port on any PC, it will periodically measure
and report in ASCII form the ambient temperature in
degrees Celsius. These temperature readings can be
monitored with any terminal program. If the terminal
program supports capture to disk, the temperature
readings can be saved to disk for further analysis with
a spreadsheet program or other data analysis tool. The
simple ASCII output format of Digitemp Jr. makes it rel-
atively easy to write custom software for receiving,
recording, and analyzing ambient temperature data.
Best of all, Digitemp Jr. requires no external power sup-
plies or batteries. It is powered directly by the RS-232 port.
為了在工業(yè)生產(chǎn)及過(guò)程控制中準(zhǔn)確測(cè)量溫度，設(shè)計(jì)了一種基于低功耗MSP430單片機(jī)的數(shù)字溫度計(jì)。整個(gè)系統(tǒng)通過(guò)單片機(jī)MSP430F1121A控制DS18B20讀取溫度，采用數(shù)碼管顯示，溫度傳感器DS18B20與單片機(jī)之間通過(guò)串口進(jìn)行數(shù)據(jù)傳輸。MSP430系列單片機(jī)具有超低功耗，且外圍的整合性高，DS18B20只需一個(gè)端口即可實(shí)現(xiàn)數(shù)據(jù)通信，連接方便。通過(guò)多次實(shí)驗(yàn)證明，該系統(tǒng)的測(cè)試結(jié)果與實(shí)際環(huán)境溫度一致，除了具有接口電路簡(jiǎn)單、測(cè)量精度高、誤差小、可靠性高等特點(diǎn)外，其低成本、低功耗的特點(diǎn)使其擁有更廣闊的應(yīng)用前景。
Abstract:
In order to obtain accurate measuring temperature in industrial production and process control， a digital thermometer based on MSP430 MCU is designed. The system uses MSP430F1121A MCU to control DS18B20， and gets the temperature data， which is displayed on the LED. The temperature sensor DS18B20 and MCU transmit data through serial communication. MSP430 series has ultra-low power and high integration， DS18B20 only needs one port to achieve data communication. Through many experimental results prove， this system is consistent with actual environment temperature. The system has characteristics of interface circuit simple， high measuring accuracy， minor error， high reliability， besides， the characteristics of low cost and low power make it having vaster application prospect.
6小時(shí)學(xué)會(huì)labview,
labview Six Hour Course – Instructor Notes
This zip file contains material designed to give students a working knowledge of labview in a 6 hour timeframe. The contents are:
Instructor Notes.doc – this document.
labviewIntroduction-SixHour.ppt – a PowerPoint presentation containing screenshots and notes on the topics covered by the course.
Convert C to F (Ex1).vi – Exercise 1 solution VI.
Convert C to F (Ex2).vi – Exercise 2 solution subVI.
thermometer-DAQ (Ex2).vi – Exercise 2 solution VI.
Temperature Monitor (Ex3).vi – Exercise 3 solution VI.
thermometer (Ex4).vi – Exercise 4 solution subVI.
Convert C to F (Ex4).vi – Exercise 4 solution subVI.
Temperature Logger (Ex4).vi – Exercise 4 solution VI.
Multiplot Graph (Ex5).vi – Exercise 5 solution VI.
Square Root (Ex6).vi – Exercise 6 solution VI.
State Machine 1 (Ex7).vi – Exercise 7 solution VI.
The slides can be presented in two three hour labs, or six one hour lectures. Depending on the time and resources available in class, you can choose whether to assign the exercises as homework or to be done in class. If you decide to assign the exercises in class, it is best to assign them in order with the presentation. This way the students can create VI’s while the relevant information is still fresh. The notes associated with the exercise slide should be sufficient to guide the students to a solution. The solution files included are one possible solution, but by no means the only solution.
The LM35 of National Semiconductors that is used in this project is a precision centigrade temperature sensor, which has an analog output voltage. It has a range of -55潞C to +150潞C and a accuracy of 鹵0.5潞C . The output voltage is 10mV/潞C . The output voltage is converted by the AD convertor of the AT Mega8. The temperature is displayed on an LCD module. In this example the thermometer has a range of 0潞C to 40潞C and a resolution of 0.5潞C. If you want to have a readout in Fahrenheit you can use the LM34.
