sht15.c

GPS模块的相关资料

/*
sht15.c


*/
#include "delay.h"
#include "sht15.h"

#define 	ACK			1
#define		NO_ACK		0


#define 	STATUS_REG_W	(0x06)
#define 	STATUS_REG_R	(0x07)
#define		MEASURE_TEMP	(0x03)
#define		MEASURE_HUMI	(0x05)
#define		RESET			(0x1e)

#define		SHT_PORT		(PORTC)
#define		SHT_DDR			(DDRC)
#define		SHT_PIN			(PINC)
#define		DATA_PIN		(0x20)
#define		SCK_PIN			(0x10)



/*
*/
void delay(void)
{
	delay_nus(10);	
}

void sht_init(void)
{
	SHT_DDR  |= DATA_PIN + SCK_PIN;
	SHT_PORT |= DATA_PIN + SCK_PIN;
	s_softreset();	
}

unsigned char s_write_byte(unsigned char value)				
{
	unsigned char i,error=0;
	SHT_DDR |= DATA_PIN;
	for(i=0x80;i>0;i/=2)
	{
		delay();
		if(i & value)
		{	
		SHT_PORT |= DATA_PIN;
		}
		else
		{
			SHT_PORT &= ~DATA_PIN;
		}
		delay();
		SHT_PORT |= SCK_PIN;
		delay();
		delay();
		delay();
		SHT_PORT &= ~SCK_PIN;
		delay();
	}
	SHT_PORT |= DATA_PIN;
	SHT_DDR &= ~DATA_PIN;
	delay();
	SHT_PORT |= SCK_PIN;
	delay();
	delay();
	delay();
	error=SHT_PIN;
	error &= DATA_PIN;
	SHT_PORT &= ~SCK_PIN;
	delay();
	return error;
}

unsigned char s_read_byte(unsigned char ack)
{
	unsigned char i,val=0;
	SHT_PORT |= DATA_PIN;
	SHT_DDR  &= ~DATA_PIN;
	for(i=0x80;i>0;i/=2)
	{
		delay();
		SHT_PORT |= SCK_PIN;
		delay();
		if(SHT_PIN & DATA_PIN)
		{
			val=(val | i);
		}
		SHT_PORT &= ~SCK_PIN;
	}
	delay();	
	if(ack==1)
	{
		SHT_DDR |= DATA_PIN;
		SHT_PORT &= ~DATA_PIN;
		delay();
		SHT_PORT |= SCK_PIN;
		delay();
		SHT_PORT &= ~SCK_PIN;
	}
	else
	{
		delay();
		SHT_PORT |= SCK_PIN;
		delay();
		SHT_PORT &= ~SCK_PIN;
	}
	return val;
}

/*
start信号

DATA_PIN   ----______------- 

SCK_PIN    ___---___---______
*/
void s_transstart(void)
{
	SHT_DDR |= DATA_PIN;

	SHT_PORT |= DATA_PIN;
	SHT_PORT &= ~SCK_PIN;
	delay();
	SHT_PORT |= SCK_PIN;
	delay();
	SHT_PORT &= ~DATA_PIN;
	delay();
	SHT_PORT &= ~SCK_PIN;
	delay();
	SHT_PORT |= SCK_PIN;
	delay();
	SHT_PORT |= DATA_PIN;
	delay();
	SHT_PORT &= ~SCK_PIN;
	delay();
}

void s_connectionreset(void)
{
	unsigned char i;
	SHT_DDR |= DATA_PIN|SCK_PIN;
	SHT_PORT |= DATA_PIN;
	SHT_PORT &= ~SCK_PIN;
	for(i=0;i<9;i++)
	{
		delay();
		SHT_PORT |= SCK_PIN;
		delay();
		SHT_PORT &= ~SCK_PIN;
	}
	s_transstart();
}


unsigned char s_softreset(void)
{
	unsigned char error=0;
	s_connectionreset();
	error+=s_write_byte(RESET);
	delay_nms(15);
	return error;
}


unsigned char s_read_statusreg(unsigned char *p_value, unsigned char *p_checksum)
{
	unsigned char error=0;
	s_transstart();
	error=s_write_byte(STATUS_REG_R);
	*p_value=s_read_byte(ACK);
	*p_checksum=s_read_byte(NO_ACK);
	return error;
}

unsigned char s_write_statusreg(unsigned char *p_value)
{
	unsigned char error=0;
	s_transstart();
	error+=s_write_byte(STATUS_REG_W);
	error+=s_write_byte(*p_value);
	return error;
}

unsigned char s_measure(unsigned char *p_value, unsigned char *p_checksum, unsigned char mode)
{
	unsigned char error=0;
	unsigned int measure_i;
	s_transstart();
	switch(mode)
	{
		case 0 :
					{
						error+=s_write_byte(MEASURE_TEMP); 
						break;
					}
		case 1 :
					{
						error+=s_write_byte(MEASURE_HUMI);
						break;
					}
		default : break;
	}
	SHT_PORT |= DATA_PIN;
	SHT_DDR &= ~DATA_PIN;
	for(measure_i=0;measure_i<65525;measure_i++)
	{
		if((SHT_PIN & DATA_PIN) == 0) break;
	}
	if((SHT_PIN & DATA_PIN))
	{
		error+=1;
	}
	*(p_value)		=s_read_byte(ACK);
	*(p_value+1)	=s_read_byte(ACK);
	*p_checksum		=s_read_byte(NO_ACK);
	return error;
}

void calc_sht(unsigned char *p_sht_data,unsigned char *p_calc_data)
{
	unsigned int temp,humi;
	unsigned char calc_i;
	temp=(((unsigned int)*p_sht_data)<<8)+(*(p_sht_data+1));
	humi=(((unsigned int)*(p_sht_data+2))<<8) + (*(p_sht_data+3));
	humi *= 3;
	for(calc_i=0;calc_i<5;calc_i++)
	{
		*(p_calc_data+4-calc_i)=((temp%10)+48);
		temp=temp/10;
	}
	for(calc_i=0;calc_i<5;calc_i++)
	{
		*(p_calc_data+9-calc_i)=((humi%10)+48);
		humi=humi/10;
	}
}