|
|
#include <reg52.h>
#include <intrins.h>
#include <math.h>
#include <stdio.h>
#define LCD_DB P0
sbit LCD_RS=P2^0;
sbit LCD_RW=P2^1;
sbit LCD_E=P2^2;
#define uchar unsigned char
#define uint unsigned int
void LCD_init(void);
void LCD_write_command(uchar command);
void LCD_write_data(uchar dat);
void LCD_disp_char(uchar x,uchar y,uchar dat);
void LCD_disp_str(uchar x,uchar y,uchar *str);
void delay_n10us(uint n);
void LCD_init(void)
{
delay_n10us(10);
LCD_write_command(0x38);//設(shè)置8位格式，2行，5x7
delay_n10us(10);
LCD_write_command(0x0c);//整體顯示，關(guān)光標(biāo)，不閃爍
delay_n10us(10);
LCD_write_command(0x06);//設(shè)定輸入方式，增量不移位
delay_n10us(10);
LCD_write_command(0x01);//清除屏幕顯示
delay_n10us(100); //延時(shí)清屏，延時(shí)函數(shù)，延時(shí)約n個(gè)10us
}
void LCD_write_command(uchar dat)
{
delay_n10us(10);
LCD_RS=0; //指令
LCD_RW=0; //寫入
LCD_E=1; //允許
LCD_DB=dat;
delay_n10us(10); //實(shí)踐證明，我的LCD1602上，用for循環(huán)1次就能完成普通寫指令。
LCD_E=0;
delay_n10us(10); //實(shí)踐證明，我的LCD1602上，用for循環(huán)1次就能完成普通寫指令。
}
void LCD_write_data(uchar dat)
{
delay_n10us(10);
LCD_RS=1; //數(shù)據(jù)
LCD_RW=0; //寫入
LCD_E=1; //允許
LCD_DB=dat;
delay_n10us(10);
LCD_E=0;
delay_n10us(10);
}
void LCD_disp_char(uchar x,uchar y,uchar dat)
{
uchar address;
if(y==1)
address=0x80+x;
else
address=0xc0+x;
LCD_write_command(address);
LCD_write_data(dat);
}
void LCD_disp_str(uchar x,uchar y,uchar *str)
{
uchar address;
if(y==1)
address=0x80+x;
else
address=0xc0+x;
LCD_write_command(address);
while(*str!='\0')
{
LCD_write_data(*str);
str++;
}
}
void delay_n10us(uint n) //延時(shí)n個(gè)10us@12M晶振
{
uint i;
for(i=n;i>0;i--)
{
_nop_();_nop_();_nop_();_nop_();_nop_();_nop_();
}
}
sbit SCK = P2^6; //定義通訊時(shí)鐘端口
sbit DATA = P2^7; //定義通訊數(shù)據(jù)端口
typedef union
{
unsigned int i; //定義了兩個(gè)共用體
float f;
} value;
enum {TEMP,HUMI}; //TEMP=0,HUMI=1
#define noACK 0 //用于判斷是否結(jié)束通訊
#define ACK 1 //結(jié)束數(shù)據(jù)傳輸
//adr command r/w
#define STATUS_REG_W 0x06 //000 0011 0
#define STATUS_REG_R 0x07 //000 0011 1
#define MEASURE_TEMP 0x03 //000 0001 1
#define MEASURE_HUMI 0x05 //000 0010 1
#define RESET 0x1e //000 1111 0
void s_transstart(void); //啟動(dòng)傳輸函數(shù)
void s_connectionreset(void); //連接復(fù)位函數(shù)
char s_write_byte(unsigned char value);//DHT90寫函數(shù)
char s_read_byte(unsigned char ack); //DHT90讀函數(shù)
char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode);
void calc_dht90(float *p_humidity ,float *p_temperature);//溫濕度補(bǔ)償
void s_transstart(void)
// generates a transmission start
// _____ ________
// DATA: |_______|
// ___ ___
// SCK : ___| |___| |______
{
DATA=1;
SCK=0; //Initial state
_nop_();
SCK=1;
_nop_();
DATA=0;
_nop_();
SCK=0;
_nop_();_nop_();_nop_();
SCK=1;
_nop_();
DATA=1;
_nop_();
SCK=0;
}
void s_connectionreset(void)
// communication reset: DATA-line=1 and at least 9 SCK cycles followed by transstart
// _____________________________________________________ ________
// DATA: |_______|
// _ _ _ _ _ _ _ _ _ ___ ___
// SCK : __| |__| |__| |__| |__| |__| |__| |__| |__| |______| |___| |______
{
unsigned char i;
DATA=1; SCK=0; //Initial state
for(i=0;i<9;i++) //9 SCK cycles
{
SCK=1;
SCK=0;
}
s_transstart(); //transmission start
}
char s_write_byte(unsigned char value)
//----------------------------------------------------------------------------------
// writes a byte on the Sensibus and checks the acknowledge
{
unsigned char i,error=0;
for (i=0x80;i>0;i/=2) //shift bit for masking
{
if (i & value) DATA=1; //masking value with i , write to SENSI-BUS
else DATA=0;
SCK=1; //clk for SENSI-BUS
_nop_();_nop_();_nop_(); //pulswith approx. 3 us
SCK=0;
}
DATA=1; //release DATA-line
SCK=1; //clk #9 for ack
error=DATA; //check ack (DATA will be pulled down by DHT90),DATA在第9個(gè)上升沿將被DHT90自動(dòng)下拉為低電平。
_nop_();_nop_();_nop_();
SCK=0;
DATA=1; //release DATA-line
return error; //error=1 in case of no acknowledge //返回：0成功，1失敗
}
char s_read_byte(unsigned char ack)
// reads a byte form the Sensibus and gives an acknowledge in case of "ack=1"
{
unsigned char i,val=0;
DATA=1; //release DATA-line
for (i=0x80;i>0;i/=2) //shift bit for masking
{
SCK=1; //clk for SENSI-BUS
if (DATA) val=(val | i); //read bit
_nop_();_nop_();_nop_(); //pulswith approx. 3 us
SCK=0;
}
if(ack==1)DATA=0; //in case of "ack==1" pull down DATA-Line
else DATA=1; //如果是校驗(yàn)(ack==0)，讀取完后結(jié)束通訊
_nop_();_nop_();_nop_(); //pulswith approx. 3 us
SCK=1; //clk #9 for ack
_nop_();_nop_();_nop_(); //pulswith approx. 3 us
SCK=0;
_nop_();_nop_();_nop_(); //pulswith approx. 3 us
DATA=1; //release DATA-line
return val;
}
char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode)
// makes a measurement (humidity/temperature) with checksum
{
unsigned error=0;
unsigned int i;
s_transstart(); //transmission start
switch(mode)
{ //send command to sensor
case TEMP : error+=s_write_byte(MEASURE_TEMP); break;
case HUMI : error+=s_write_byte(MEASURE_HUMI); break;
default : break;
}
for (i=0;i<65535;i++)
if(DATA==0)
break; //wait until sensor has finished the measurement
if(DATA) error+=1; // or timeout (~2 sec.) is reached
*(p_value) =s_read_byte(ACK); //read the first byte (MSB)
*(p_value+1)=s_read_byte(ACK); //read the second byte (LSB)
*p_checksum =s_read_byte(noACK); //read checksum
return error;
}
void calc_dht90(float *p_humidity ,float *p_temperature)
// calculates temperature [C] and humidity [%RH]
// input : humi [Ticks] (12 bit)
// temp [Ticks] (14 bit)
// output: humi [%RH]
// temp [C]
{
const float C1=-4.0; // for 12 Bit
const float C2=+0.0405; // for 12 Bit
const float C3=-0.0000028; // for 12 Bit
const float T1=+0.01; // for 14 Bit @ 5V
const float T2=+0.00008; // for 14 Bit @ 5V
float rh=*p_humidity; // rh: Humidity [Ticks] 12 Bit
float t=*p_temperature; // t: Temperature [Ticks] 14 Bit
float rh_lin; // rh_lin: Humidity linear
float rh_true; // rh_true: Temperature compensated humidity
float t_C; // t_C : Temperature [C]
t_C=t*0.01 - 40; //calc. temperature from ticks to [C]
rh_lin=C3*rh*rh + C2*rh + C1; //calc. humidity from ticks to [%RH]
rh_true=(t_C-25)*(T1+T2*rh)+rh_lin-3; //calc. temperature compensated humidity [%RH]
if(rh_true>100)rh_true=100; //cut if the value is outside of
if(rh_true<0.1)rh_true=0.1; //the physical possible range
*p_temperature=t_C; //return temperature [C]
*p_humidity=rh_true; //return humidity[%RH]
}
void main(void)
{
value humi_val,temp_val;
unsigned char error,checksum;
unsigned int wendu,shidu;
LCD_init();
s_connectionreset();
LCD_disp_str(0,1,"TE");
LCD_disp_str(0,2,"RH");
//*********初始化溫度顯示區(qū)*********
LCD_disp_str(2,1,"TTT.TC");
//*********初始化濕度顯示區(qū)*********
LCD_disp_str(2,2,"RRR.R%");
delay_n10us(20000); //延時(shí)0.2s
while(1)
{
error=0;
error+=s_measure((unsigned char*) &humi_val.i,&checksum,HUMI); //measure humidity
error+=s_measure((unsigned char*) &temp_val.i,&checksum,TEMP); //measure temperature
if(error!=0) s_connectionreset(); //in case of an error: connection reset
else
{
humi_val.f=(float)humi_val.i; //converts integer to float
temp_val.f=(float)temp_val.i; //converts integer to float
calc_dht90(&humi_val.f,&temp_val.f); //calculate humidity, temperature
wendu=10*temp_val.f;
LCD_disp_char(2,1,wendu/1000+'0'); //顯示溫度百位
LCD_disp_char(3,1,(wendu%1000)/100+'0'); //顯示溫度十位
LCD_disp_char(4,1,(wendu%100)/10+'0'); //顯示溫度個(gè)位
LCD_disp_char(6,1,(wendu%10)+'0'); //顯示溫度小數(shù)點(diǎn)后第一位
shidu=10*humi_val.f;
LCD_disp_char(2,2,shidu/1000+'0'); //顯示濕度百位
LCD_disp_char(3,2,(shidu%1000)/100+'0'); //顯示濕度十位
LCD_disp_char(4,2,(shidu%100)/10+'0'); //顯示濕度個(gè)位
LCD_disp_char(6,2,(shidu%10)+'0'); //顯示濕度小數(shù)點(diǎn)后第一位
}
//----------wait approx. 0.8s to avoid heating up SHTxx------------------------------
delay_n10us(80000); //延時(shí)約0.8s
}
}
全部資料51hei下載地址：
sht75+1602.rar
(76.44 KB, 下載次數(shù): 38)
2020-1-31 19:52 上傳
點(diǎn)擊文件名下載附件
|
評(píng)分
-
查看全部評(píng)分
|
