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各位大侠，硬件电路DATA线上接了一个10K的上拉电阻，但是怎么试就是不好使，急死我了，请帮我看看吧！谢啦！
ICC AVR编的，用的ATMega 128
#define SHT2MCU_Data (!(!(PIND&0x02)))
#define SHT11_DataOut DDRD|=BIT(2) //PD口的2位设置为输出
#define SHT11_DataIn DDRD&=~BIT(2) //PD口的2位设置为输入
#define SHT11_ClkOut DDRD|=BIT(1) //PD口的1位设置为输出
#define SHT11_CLK_H PORTD|= BIT(1) //PD1
#define SHT11_CLK_L PORTD&=~BIT(1) //PD1
#define SHT11_DATA_H PORTD|= BIT(2) //PD2
#define SHT11_DATA_L PORTD&=~BIT(2) //PD2
#include "config.h" //这里有我的delay函数，还iom128v.h等头文件
#include <math.h>
#include <stdio.h>
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
//----------------------------------------------------------------------------------
// modul-var
//----------------------------------------------------------------------------------
enum {TEMP,HUMI};
#define DATA P1_1
#define SCK P1_0
#define noACK 0
#define ACK 1
//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
//----------------------------------------------------------------------------------
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;
SHT11_DataOut;
SHT11_ClkOut;
SHT11_DATA_H; //release DATA-line
SHT11_DataIn;
SHT11_DATA_L;
delay_us(2);
for (i=0x80;i>0;i/=2) //shift bit for masking
{
SHT11_CLK_H; //clk for SENSI-BUS
delay_us(2);
if (SHT2MCU_Data) val=(val | i); //read bit
SHT11_CLK_L;
delay_us(2);
}
//DATA=!ack; //in case of "ack==1" pull down DATA-Line
SHT11_DataOut;
if(ack==1)
SHT11_DATA_L;
else
SHT11_DATA_H;
delay_us(2);
SHT11_CLK_H; //clk #9 for ack
delay_us(5); //pulswith approx. 5 us
SHT11_CLK_L;
delay_us(2);
SHT11_DATA_H; //release DATA-line
return val;
}
//----------------------------------------------------------------------------------
char s_write_byte(unsigned char value)
//----------------------------------------------------------------------------------
// writes a byte on the Sensibus and checks the acknowledge
{
unsigned char ibit,error=0;
SHT11_ClkOut;
SHT11_DataOut;
for (ibit=0x80;ibit>0;ibit/=2) //shift bit for masking
{
if (ibit & value)
SHT11_DATA_H; //masking value with i , write to SENSI-BUS
else SHT11_DATA_L;
delay_us(2);
SHT11_CLK_H; //clk for SENSI-BUS
delay_us(5); //pulswith approx. 5 us
SHT11_CLK_L;
delay_us(2);
}
SHT11_DATA_H; //release DATA-line
delay_us(2);
SHT11_CLK_H; //clk #9 for ack
SHT11_DataIn;
SHT11_DATA_L;
delay_us(2);
error=SHT2MCU_Data; //check ack (DATA will be pulled down by SHT11)
SHT11_CLK_L;
return error; //error=1 in case of no acknowledge
}
//----------------------------------------------------------------------------------
void s_transstart(void)
//----------------------------------------------------------------------------------
// generates a transmission start
// _____ ________
// DATA: |_______|
// ___ ___
// SCK : ___| |___| |______
{
SHT11_DataOut;
SHT11_ClkOut;
SHT11_DATA_H; SHT11_CLK_L; //Initial state
delay_us(2);
SHT11_CLK_H;
delay_us(2);
SHT11_DATA_L;
delay_us(2);
SHT11_CLK_L;
delay_us(5);
SHT11_CLK_H;
delay_us(2);
SHT11_DATA_H;
delay_us(2);
SHT11_CLK_L;
delay_us(2);
}
//----------------------------------------------------------------------------------
void s_connectionreset(void)
//----------------------------------------------------------------------------------
// communication reset: DATA-line=1 and at least 9 SCK cycles followed by transstart
// _____________________________________________________ ________
// DATA: |_______|
// _ _ _ _ _ _ _ _ _ ___ ___
// SCK : __| |__| |__| |__| |__| |__| |__| |__| |__| |______| |___| |______
{
unsigned char i;
SHT11_DataOut;
SHT11_ClkOut;
SHT11_DATA_H; SHT11_CLK_L; //Initial state
delay_us(2);
for(i=0;i<9;i++) //9 SCK cycles
{
SHT11_CLK_H;
delay_us(2);
SHT11_CLK_L;
delay_us(2);
}
s_transstart(); //transmission start
}
//----------------------------------------------------------------------------------
char s_softreset(void)
//----------------------------------------------------------------------------------
// resets the sensor by a softreset
{
unsigned char error=0;
s_connectionreset(); //reset communication
error+=s_write_byte(RESET); //send RESET-command to sensor
return error; //error=1 in case of no response form the sensor
}
//----------------------------------------------------------------------------------
char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum)
//----------------------------------------------------------------------------------
// reads the status register with checksum (8-bit)
{
unsigned char error=0;
s_transstart(); //transmission start
error=s_write_byte(STATUS_REG_R); //send command to sensor
*p_value=s_read_byte(ACK); //read status register (8-bit)
*p_checksum=s_read_byte(noACK); //read checksum (8-bit)
return error; //error=1 in case of no response form the sensor
}
//----------------------------------------------------------------------------------
char s_write_statusreg(unsigned char *p_value)
//----------------------------------------------------------------------------------
// writes the status register with checksum (8-bit)
{
unsigned char error=0;
s_transstart(); //transmission start
error+=s_write_byte(STATUS_REG_W);//send command to sensor
error+=s_write_byte(*p_value); //send value of status register
return error; //error>=1 in case of no response form the sensor
}
//----------------------------------------------------------------------------------
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;
}
SHT11_DataIn;
SHT11_DATA_L;
for (i=0;i<65535;i++) if(SHT2MCU_Data==0) break; //wait until sensor has finished the measurement
if(SHT2MCU_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_sth11(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]
{
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; //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]
}
//--------------------------------------------------------------------
float calc_dewpoint(float h,float t)
//--------------------------------------------------------------------
// calculates dew point
// input: humidity [%RH], temperature [.C]
// output: dew point [.C]
{
float logEx,dew_point ;
logEx=0.66077+7.5*t/(237.3+t)+(log10(h)-2) ;
dew_point = (logEx - 0.66077)*237.3/(0.66077+7.5-logEx) ;
return dew_point;
}
//----------------------------------------------------------------------------------
void main()
//----------------------------------------------------------------------------------
// sample program that shows how to use SHT11 functions
// 1. connection reset
// 2. measure humidity [ticks](12 bit) and temperature [ticks](14 bit)
// 3. calculate humidity [%RH] and temperature [.C]
// 4. calculate dew point [.C]
// 5. print temperature, humidity, dew point
{
unsigned int humi_vali=0,temp_vali=0;
float humi_valf=0,temp_valf=0;
float dew_point;
unsigned char error,checksum;
unsigned int i;
s_connectionreset();
while(1)
{
s_measure((unsigned char*) &humi_vali,&checksum,HUMI);
s_measure((unsigned char*) &temp_vali,&checksum,TEMP);
humi_valf=(float)humi_vali; //converts integer to float
temp_valf=(float)temp_vali; //converts integer to float
calc_sth11(&humi_valf,&temp_valf); //calculate humidity, temperature
dew_point=calc_dewpoint(humi_valf,temp_valf); //calculate dew point
//----------wait approx. 0.8s to avoid heating up SHTxx------------------------------
for (i=0;i<40000;i++); //(be sure that the compiler doesn’t eliminate this line!)
//-----------------------------------------------------------------------------------
}
} |
阿莫论坛20周年了！感谢大家的支持与爱护！！
知道什么是神吗？其实神本来也是人，只不过神做了人做不到的事情 所以才成了神。 （头文字D, 杜汶泽）
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发表于 2009-12-31 17:22:13
楼主
