Along with modern industry development, people's living standard obtained the unprecedented enhancement. Also has created the huge wealth for the human society. The Key for modern industry level of development
is humanity's accurate survey and the control for each kind of parameter in industry control, and must depend upon the level of development of various sensor. Temperature survey is taken as essential technology in
industrial production.
The present paper introduced one kind of new digital thermometer which take single-chip as the primary control component, take DS18B20 as the temperature sensor. Mainly includes the hardware circuit design and the system program design. The hardware circuit mainly includes the master control, temperature measured circuit and the display circuit and so on, the master control uses single-chip AT89C2051, the temperature sensor uses DS18B20 which the American DALLAS semiconductor company produces, the display circuit uses numerical code tube with 4 altogether anodes LED and straight to read the display by dynamic scanning method. The system program mainly includes the master routine, the read-out temperature subroutine, the temperature transformation order subroutine, the calculated temperature subroutine; displayed data renovate subroutine and so on. In addition, also introduced the system debugging and the performance analysis.
Because used the advanced version of intelligence temperature sensor DS18B20 as examination component, compared with the traditional thermometer, this digital thermometer reduced the external hardware electric circuit, and has characteristic which is low cost and easy to use. The DS18B20 thermometer can carry on application development in different aspect: alarm in high temperature, temperature measurement with long-distance range and multi- spots. and it has the very good prospects for development.
Key word: single chip, master control, temperature sensor, DS18B20, AT89C2051, display circuit, digital thermometer