Urine Analyzer Design Based On Color Recognition

This paper gives the design of a urine analysing instrument based on color distinguish of test sample. It can do 8 or 11 urine routine tests.The analysing system uses a P89v51RD2 as microprocessor, encludes two extended 8255 chips, a 74HC573 data buffer. In address design , the address encoder 74LS138 is adopted to provdes an accurate time clock for the system, and give 1khz frequency of carrier wave to the sample sensor. The unlosable RAM of DAS1230 can store test data with a capacity of 32 k bites, almost 1 thousand lines of test data. The system programe of analyser is writen in KeilC language, and operated on the stages of uVision and MedWin. The unique IAP funcion of P89V51 ensures the stability of sacling storage, and it is made true by the mixture of C51 and compile program .The input hardware is a 4×4 array key borad , with 10 number keys and 6 function control keys.And line reverse Input/Output method is used to identify keys. The disply unit is a 128×64 graphics LCD screen.In order to improve operation continuity and test rapidity, the system selects 3 step-by-step motors (push motor, move motor, and test motor), and a continiously collecting and testing motion mechnism. The motors are all controled by 5804 chips with simple electric circuits and steady-going operation. The sensitive model of sample paper uses the technique of light pulses modulation , in the process, the CAL16V20 chip makes the light tube give out carrier source of 1 kHz. Any changes of light line intension can be sensed by high accurate photronic. There are Band-Pass Filter in the calculating amplifier circuits to shield off the disturbing light from the enviroment. In AD exchange circuit there is a ADC0804. When testing, the reference value can be preset or modified, and the sensitivity can be adjusted at any time.Considering of the importantance of testing result print for the instrument, A high speed termal mini printer mechanism LTP1235 is used and controled by an ralitive independent micro printer module. This module is in series comunication linkage with the main control system via RS232 interface. A STC89C58 is used as main control chip. An internal 32k- bite programe storage ROM for program and normal words , A 1280-bite data storage RAM, and a 24 k- bite EEPROM for in time enlarging word-base are also used.The printing head has two terminal lines, one of 20 lines as Thermal Head Contral Terminal(FFC).The other of 9 as Motor and Detector Terminal(FPC). The LTP1245 contains a thermal head with 384 heat elements(dot-size), arranged in rows, and only a row is printed every time. Correspondingly, there are 384 shift registers to control heating elements. The data are inputed by main control chip via DAT and CLK, and latched after delivery and the pin being set low.The pulse wide of DST high level, i,e, the control of heating time is the key of system design. And we have found the most suitble heating time by calculating. Besides, the system has many function such as sample paper shortage alarm, paper intering direction test. And over-temprature self protection.The module of color identification is the kernal of analysing system. We used the newst sensor of TCS230. It has an8×8array of photodiodes and packaged with 64 photoelectricity diode in a single chip. The diodes are classfied as red, yellow, blue and white light.testing unit. In software design, two timer are used, with OUT pin to T1 input to set counter manner to take count, and T0 to set timing manner to time. In certain time the fiequncy value collected is the color date. It can be changed in unit if necessary and adjusted by proportion coefficent after white balance test.The color distinguish arithmetic program is based on large number of experiments. It can find out the color characterastic of all test data.