这个芯片怎么说呢！比较贵！！但性能比较不错！
但就是不知道怎么标定（我想看看到底准不准，实践出真理）！！
下面是用mega8改写的程序，在测量程序里我改了一下读取温、湿度的顺序，因为按照原程序的顺序读出来结果不正确，改了后就这正确了（这是没修改的）。有什么问题大家一起讨论。QQ:48801015
/*********************************************
This program was produced by the
CodeWizardAVR V1.23.8c Professional
Automatic Program Generator
?Copyright 1998-2003 HP InfoTech s.r.l.
http://www.hpinfotech.ro
e-mail:office@hpinfotech.ro
Project :
Version :
Date : 30.03.2004
Author : Nick Schres
Company :
Comments:
Chip type : ATmega8
Program type : Application
Clock frequency : 8,000000 MHz
Memory model : Small
External SRAM size : 0
Data Stack size : 256
*********************************************/
#include <mega8.h>
#include <delay.h>
#include <stdlib.h>
// Alphanumeric LCD Module functions
#asm
.equ __lcd_port=0x12
#endasm
#include <lcd.h>
// Declare your global variables here
char s_write_byte(unsigned char value);
char s_read_byte(unsigned char ack);
void s_transstart(void);
void s_connectionreset(void);
char s_softreset(void);
char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum);
char s_write_statusreg(unsigned char *p_value);
char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode);
void calc_sth11(float *p_humidity ,float *p_temperature);
typedef union
{ unsigned int i;
float f;
} value;
enum {TEMP,HUMI};
#define DATA_OUT PORTC.0
#define DATA_IN PINC.0
#define SCK PORTC.1
#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
void main(void)
{
// Declare your local variables here
value humi_val,temp_val;
unsigned char error,checksum;
unsigned char outp;
char inp;
// Input/Output Ports initialization
// Port B initialization
// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In
// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T
PORTB=0x00;
DDRB=0x00;
// Port C initialization
// Func0=In Func1=Out Func2=In Func3=In Func4=In Func5=In Func6=In
// State0=T State1=0 State2=T State3=T State4=T State5=T State6=T
PORTC=0x00;
DDRC=0x02;
// Port D initialization
// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In
// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T
PORTD=0x00;
DDRD=0x00;
// Timer/Counter 0 initialization
// Clock source: System Clock
// Clock value: Timer 0 Stopped
TCCR0=0x00;
TCNT0=0x00;
// Timer/Counter 1 initialization
// Clock source: System Clock
// Clock value: Timer 1 Stopped
// Mode: Normal top=FFFFh
// OC1A output: Discon.
// OC1B output: Discon.
// Noise Canceler: Off
// Input Capture on Falling Edge
TCCR1A=0x00;
TCCR1B=0x00;
TCNT1H=0x00;
TCNT1L=0x00;
OCR1AH=0x00;
OCR1AL=0x00;
OCR1BH=0x00;
OCR1BL=0x00;
// Timer/Counter 2 initialization
// Clock source: System Clock
// Clock value: Timer 2 Stopped
// Mode: Normal top=FFh
// OC2 output: Disconnected
ASSR=0x00;
TCCR2=0x00;
TCNT2=0x00;
OCR2=0x00;
// External Interrupt(s) initialization
// INT0: Off
// INT1: Off
GICR|=0x00;
MCUCR=0x00;
// Timer(s)/Counter(s) Interrupt(s) initialization
TIMSK=0x00;
// Analog Comparator initialization
// Analog Comparator: Off
// Analog Comparator Input Capture by Timer/Counter 1: Off
// Analog Comparator Output: Off
ACSR=0x80;
SFIOR=0x00;
// LCD module initialization
lcd_init(20);
// 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 [癈]
// 4. print temperature, humidity
s_connectionreset();
while(1)
{ error=0;
// delay_ms(200);
// error+=s_measure((unsigned char*) &humi_val.i,&checksum,HUMI); //measure humidity
// delay_ms(200);
// error+=s_measure((unsigned char*) &temp_val.i,&checksum,TEMP); //measure temperature
error += s_read_statusreg(&inp, &checksum);
if(error!=0)
{s_connectionreset(); //in case of an error: connection reset
lcd_clear();
lcd_gotoxy(0,0);
lcd_putsf("Error");
}
else
{ humi_val.f=(float)humi_val.i; //converts integer to float
temp_val.f=(float)temp_val.i; //converts integer to float
calc_sth11(&humi_val.f,&temp_val.f); //calculate humidity, temperature
itoa(inp,&outp);
lcd_clear();
lcd_gotoxy(0,0);
lcd_puts(&outp);
itoa(humi_val.i,&outp);
lcd_gotoxy(0,2);
lcd_puts(&outp);
}
//----------wait approx. 0.8s to avoid heating up SHTxx------------------------------
delay_ms(800);
//-----------------------------------------------------------------------------------
}
}
//----------------------------------------------------------------------------------
// writes a byte on the Sensibus and checks the acknowledge
//----------------------------------------------------------------------------------
char s_write_byte(unsigned char value)
{
unsigned char i,error=0;
DDRC = 0b00000011; // DATA Ausgang
for (i=0x80;i>0;i/=2) //shift bit for masking
{
if (i & value) DATA_OUT=1; //masking value with i , write to SENSI-BUS
else DATA_OUT=0;
delay_us(2);
SCK=1; //clk for SENSI-BUS
delay_us(5); //pulswith approx. 5 us
SCK=0;
}
DATA_OUT=0;
DDRC = 0b00000010; // DATA Eingang
SCK=1; //clk #9 for ack
delay_us(2);
error=DATA_IN; //check ack (DATA will be pulled down by SHT11)
delay_us(2);
SCK=0;
return error; //error=1 in case of no acknowledge
}
/*
char s_write_byte(unsigned char value)
{
unsigned char i,error=0;
DDRC = 0b00000011; // DATA Ausgang
for (i=0x80;i>0;i/=2) //shift bit for masking
{ if (i & value) DATA_OUT=1; //masking value with i , write to SENSI-BUS
else DATA_OUT=0;
SCK=1; //clk for SENSI-BUS
delay_us(5); //pulswith approx. 5 us
SCK=0;
}
DDRC = 0b00000010; // DATA Eingang
delay_us(2); //pulswith approx. 5 us
SCK=1; //clk #9 for ack
delay_us(5); //pulswith approx. 5 us
error=DATA_IN; //check ack (DATA will be pulled down by SHT11)
SCK=0;
return error; //error=1 in case of no acknowledge
}
*/
//-------
