ABSTRACT
With the application of micro-electronics technology, tradition ponderation
instrument used in market has been not satisfaction with human requirements already.
In order to make up for the traditional apparatus shortcoming, we improve the
apparatus's control system with intelligence and automation. This system is mainly
controlled by microcontroller, the section of height measurement accomplish by
supersonic sensor, the section of weight measurement accomplish by weight sensor
and A/D transformer, this apparatus have many characteristic such as having more
function, consume less energy, small and move easily, low price, measure precisely,
the speed is quick, automatic work without people and so on.
The system is mainly controlled by the microcontroller89C51, the periphery is
consist of the circuit of clock and calendar, the circuit of measure height and weight,
the circuit of display and print, all of these comprise the circuit board of the intelligent
apparatus of height and weight. It can achieve all function of the apparatus.
When he was called in the objects placed on the scale, the weight and belt scales
body through to weighing transducer, sensor generates electricity effect - the weight
of the object, will be converted to a certain weight called objects (general function
relation is proportional to the relationship between signal (the) voltage or current, etc.).
This signal by amplifying circuit, the amplification by filter / (A/D) device, digital
signals into tiny place of CPU, CPU scanning switch, all sorts of functions and
keyboard according to various functions and keyboard input switch to judge, analysis,
by the software to control all kinds of instruments. Computational results showed that
need to Cun Zhu Qi inside when the CPU, from inside CunZhuQi instruction in
reading to display, or send the printer. Generally, the signal filter, A/D conversion and
signal processing various operations in instrumentation.
Keywords: 89C51 singlechip ; ponderation –sensor; LED display ;
software
