The detection system is composed of single chip microcomputer（ SCM） which is used as controller

weight sensing detecting circuit

analog to digital（ A/D） conversion acquisition circuit

key input circuit

liquid crystal display（ LCD） output circuit and serial communication. After weighing

sensing

detecting

amplifying

A/D collecting and converting

the datasets acquired from the detection system are transmitted to upper PC via serial port

and the characteristic curve of the detection system is fitted by PC computing the datasets. The nutrition value of the tested food is calculated and displayed on the LCD according to the characteristic parameters. The result shows that the design is simple and accurate

and can meet the nutrition demands of different individuals.