单片机线性插值计算温度值(0～1200°C范围的 K分度表，每隔5) -

#include<reg51.h>
#include<stdio.h>
#include<math.h>
#define uint unsigned int
#define uchar unsigned char
unsigned int temp;
unsigned char t[6] ={"0000`C"} ;
float U1;
unsigned int code K_TABLE[242]={0,198,397,597,798,1000,1203,1407,1614,1817,2022,2229,2436,2643,2850,3058,3266,
3473,3681,3888,4095,4302,4508,4714,4919,5124,5327,5531,5733,5936,6137,6338,6539,6739,6939,7139,7338,7538,7737,7937,8137,8336,8537,8737,8938,
9139,9341,9543,9745,9948,10151,10355,10560,10764,10969,11175,11381,11587,11793,12000,12207,12415,12623,12831,13039,13247,13456,13665,13874,
14083,14292,14502,14712,14922,15132,15342,15552,15763,15974,16184,16395,16607,16818,17029,17241,17453,17664,17876,18088,18301,18513,18725,18938,
19150,19363,19576,19788,20001,20214,20427,20640,20853,21066,21280,21493,21706,21919,22132,22346,22559,22772,22985,23198,23411,23624,23837,24050,
24263,24476,24689,24902,25114,25327,25539,25751,25964,26176,26387,26599,26811,27022,27234,27445,27656,27867,28078,28288,28498,28709,28919,29128,
29338,29547,29756,29965,30174,30383,30591,30799,31007,31214,31422,31629,31836,32042,32249,32455,32661,32866,33072,33277,33482,33686,33891,34095,
34299,34502,34705,34909,35111,35314,35516,35718,35920,36121,36323,36524,36724,36925,37125,37325,37524,37923,38122,38320,38519,38717,38915,39112,
39310,39546,39703,39900,40096,40292,40488,40634,40897,41074,41296,41463,41657,41851,42045,42239,42432,42625,42817,43010,43202,43394,43585,43777,
43968,44159,44349,44539,44729,44919,45108,45297,45486,45675,45863,46051,46238,46425,46612,46799,46985,47171,47356,47542,47726,47911,48095,48279,48462,48645,48828
};//0～1200°C范围的 K分度表，每隔5
sbit RS=P2^0; //数据(L)/命令(H)选择
sbit LCDRW=P2^1; //写，低电平有效
sbit EN=P2^2; //使能,低电平有效
sbit START=P2^3;
sbit ALE=P2^4;
sbit EOC=P2^5;
sbit OE=P2^6;
unsigned int search (float input);
void conv_start(void);
void conv_check(void);
int read_data(void);
void delay_ms(int);
void write_data(char);
void write_com(char);
void LCD_home(void);
void lcd_init();
void print_string(char*);
//----------------------------------------------------------------------------
void main()
{
int res=0;
float vol=0.0;
float vin;
unsigned int tempin;
char pr[8];
lcd_init();
while(1)
{
res=read_data();
vol=5.0*res/255;
vin=vol/10*1000;
tempin=search(vin);
sprintf(pr,"%d",tempin);
LCD_home();
print_string("Temperature:");
print_string(pr);
write_data(0xDF);
print_string("C ");
}
}
//----------------------------------------------------------------------------
unsigned int search (float input) /*+查表子函数*/
{
unsigned int da=0,max,min,mid,j;
da=input*1000; /*u1扩大1000倍 */
//da=da+1203;//30 度
max=242;
min=0;
temp=0;
while(1)
{
mid=(max+min)/2; /*中心元素位置*/
if(K_TABLE[mid]==da)
{
temp=mid*5;
break;
} /*中心元素等于查表的元素,计算相应温度*/
if(K_TABLE[mid]>da)
max=mid-1;
else
min=mid+1;
if((max-min)==1 ) /*线性插值计算温度值*/
{
if(da >= K_TABLE[min])
{
j=(K_TABLE[max]- K_TABLE[min])/5; /*表中相邻两值对应温度相差5°C*/
j=(da- K_TABLE[min])/j;
temp=5*min+j;
break;
}
if(da <= K_TABLE[min])
{
j=(K_TABLE[max]- K_TABLE[min])/5; /*表中相邻两值对应温度相差5°C*/
j=(K_TABLE[min]-da )/j;
temp=5*min-j;
break;
}
}
if(max==min)
{
if(da >= K_TABLE[min])
{
j=(K_TABLE[min+1]- K_TABLE[min])/5;
j=(da- K_TABLE[min])/j;
}
else if(da < K_TABLE[min])
{
j=(K_TABLE[min]- K_TABLE[min-1])/5;
j=(da- K_TABLE[min-1])/j;
min = min -1;
}
temp=5*min+j;
break;
}
}
return temp;
}
//----------------------------------------------------------------------------
void conv_start()
{
ALE=1;
START=1;
delay_ms(1); //当晶振较高时加延时
ALE=0;
START=0;
// delay_ms(5); //当晶振较高时加延时
}
//----------------------------------------------------------------------------
int read_data()
{
int i=0;
OE=1;
conv_start();
while(!EOC);
i=P1;
OE=0;
return i;
}
//----------------------------------------------------------------------------
void delay_ms(int t)
{
int j;
for( ;t!=0; t--)
for(j=0;j<255;j++);
}
//----------------------------------------------------------------------------
void write_data(char dat)
{
RS=1; //数据
LCDRW=0; //写
P0=dat; //把数据送到P口
delay_ms(5); //当晶振较高时加延时
EN=1;
delay_ms(5); //当晶振较高时加延时
EN=0; //关使能
}
//----------------------------------------------------------------------------
void write_com(char com)
{
RS=0; //命令
LCDRW=0; //写
P0=com;
delay_ms(5); //当晶振较高时加延时
EN=1;
delay_ms(5); //当晶振较高时加延时
EN=0;
}
//----------------------------------------------------------------------------
void LCD_home(void)
{
write_com(0x02);
}
//----------------------------------------------------------------------------
void lcd_init()
{
LCDRW=0;
RS=0;
write_com(0x36); //set text home address
write_com(0x0c); //display on,cursor off,blink off
write_com(0x38);
write_com(0x06); //input set.
write_com(0x01); //screen clear
write_com(0x80); //DDRAM AD set to 00h,
}
//----------------------------------------------------------------------------
void print_string(char* str)
{
int i;
for(i=0;str[ i]!=0;i++)
{
write_data(str[ i]);
}
}

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