SI7021基于STM32f0

453044814@qq.co · 发表于 2016-6-23 17:22:51

#include "SI7020.H"
#include "usart.h"
#define SI7021_W 0x80
#define SI7021_R 0x81

//3õê¼»ˉIIC
void IIC_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOB|RCC_AHBPeriph_GPIOD, ENABLE ); //ê1ÄüGPIOBê±Öó
   //SCL  PB3
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT ;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//SDA PD2
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT ;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_SetBits(GPIOD,GPIO_Pin_2);
GPIO_SetBits(GPIOB,GPIO_Pin_3);
}

void SDA_OUT(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;//PA6:SDA
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT ; //íÆíìêä3ö
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
}
void SDA_IN(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;//PA6:SDA
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN ;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
}
//2úéúIICÆeê¼DÅoÅ
void IIC_Start(void)
{
SDA_OUT();    //sdaÏßêä3ö
IIC_SDA_1;
IIC_SCL_1;
delay_us(4);
IIC_SDA_0;//START:when CLK is high,DATA change form high to low
delay_us(4);
IIC_SCL_0;//Çˉ×¡I2C×üÏß￡¬×¼±¸·￠Ëí»ò½óêÕêy¾Y
}
//2úéúIICí￡Ö1DÅoÅ
void IIC_Stop(void)
{
SDA_OUT();//sdaÏßêä3ö
IIC_SCL_0;
IIC_SDA_0;//STOP:when CLK is high DATA change form low to high
delay_us(4);
IIC_SCL_1;
IIC_SDA_1;//·￠ËíI2C×üÏß½áêøDÅoÅ
delay_us(4);
}
//μè′yó|′eDÅoÅμ½à′
//·μ»ØÖμ￡o1￡¬½óêÕó|′eê§°ü
//       0￡¬½óêÕó|′e3é1|
u8 IIC_Wait_Ack(void)
{
u8 ucErrTime=0;
SDA_IN();    //SDAéèÖÃÎaêäèë
IIC_SDA_1;delay_us(1);
IIC_SCL_1;delay_us(1);
while(READ_SDA)
{
ucErrTime++;
if(ucErrTime>250)
{
IIC_Stop();
return 1;
}
}
IIC_SCL_0;//ê±Öóêä3ö0
return 0;
}
//2úéúACKó|′e
void IIC_Ack(void)
{
IIC_SCL_0;
SDA_OUT();
IIC_SDA_0;
delay_us(2);
IIC_SCL_1;
delay_us(2);
IIC_SCL_0;
}
//2»2úéúACKó|′e
void IIC_NAck(void)
{
IIC_SCL_0;
SDA_OUT();
IIC_SDA_1;
delay_us(2);
IIC_SCL_1;
delay_us(2);
IIC_SCL_0;
}
//IIC·￠Ëíò»¸ö×Ö½ú
//·μ»Ø′ó»úóDÎTó|′e
//1￡¬óDó|′e
//0￡¬ÎTó|′e
void IIC_Send_Byte(u8 txd)
{
u8 t;
SDA_OUT();
IIC_SCL_0;//à-μíê±Öó¿aê¼êy¾Y′«êä
for(t=0;t<8;t++)
{
if(txd&0x80)IIC_SDA_1;
else IIC_SDA_0;
// IIC_SDA=(txd&0x80)>>7;
      txd<<=1;
delay_us(4); //¶ÔTEA5767Õaèy¸öÑóê±¶¼êÇ±ØDëμÄ
IIC_SCL_1;
delay_us(4);
IIC_SCL_0;
delay_us(4);
}
}
//¶á1¸ö×Ö½ú￡¬ack=1ê±￡¬·￠ËíACK￡¬ack=0￡¬·￠ËínACK
u8 IIC_Read_Byte(unsigned char ack)
{
unsigned char i,receive=0;
SDA_IN();//SDAéèÖÃÎaêäèë
for(i=0;i<8;i++ )
{
      IIC_SCL_0;
      delay_us(4);
IIC_SCL_1;
      receive<<=1;
      if(READ_SDA)receive++;
delay_us(4);
}
if (!ack)
      IIC_NAck();//·￠ËínACK
else
      IIC_Ack(); //·￠ËíACK
return receive;
}

/*
1|Äü:¶áè¡êa¶è

*/
float ReadHumidity(void)
{
uint16_t data ;
float Humi;
IIC_Start();
IIC_Send_Byte(0X80);       //·￠Ëí′ó»úμØÖ·  D′
if(IIC_Wait_Ack()) return 1;//ó|′eê§°ü
IIC_Send_Byte(0XE5);       //·￠Ëí ¶áêa¶è
if(IIC_Wait_Ack()) return 2;//ó|′eê§°ü
delay_ms(100);
IIC_Start();
IIC_Send_Byte(0X81);       //·￠Ëí′ó»úμØÖ·  ¶á
if(IIC_Wait_Ack()) return 3;//ó|′eê§°ü
data = IIC_Read_Byte(1);//¸ß°ËÎ» 1»Øó|ACK
data = data<<8;
data = data + IIC_Read_Byte(0);//μí°ËÎ»
IIC_Stop();//2úéúò»¸öí￡Ö1ìõ¼t
Humi = 125.00f * data / 65536 - 6;
return Humi;
}
/*
¶áè¡ÎÂ¶è
*/
float ReadTemperature(void)
{
uint16_t data ;
float Temp;
IIC_Start();
IIC_Send_Byte(0X80);       //·￠Ëí′ó»úμØÖ·  D′
if(IIC_Wait_Ack()) return 1;//ó|′eê§°ü
IIC_Send_Byte(0XE3);       //·￠Ëí ¶áÎÂ¶è
if(IIC_Wait_Ack()) return 2;//ó|′eê§°ü
delay_ms(100); //×a»»Dèòaê±¼ä,ò»¿aê¼Ã»óD¼óÕa¸öÑóê±ò»Ö±μ÷2»3öà′
IIC_Start();
IIC_Send_Byte(0X81);       //·￠Ëí′ó»úμØÖ·  ¶á
if(IIC_Wait_Ack()) return 3;//ó|′eê§°ü
data = IIC_Read_Byte(1);//¸ß°ËÎ» »Øó|ACK
data = data<<8;
data = data + IIC_Read_Byte(0);//μí°ËÎ»
IIC_Stop();//2úéúò»¸öí￡Ö1ìõ¼t
Temp = 175.72 * data / 65536.0 - 46.85;
return Temp;
}

453044814@qq.co · 发表于 2016-6-23 17:26:21

伸手党们用完，记得看懂

453044814@qq.co · 发表于 2016-6-23 17:23:17

#ifndef __SI7020_H
#define __SI7020_H

#include "system.h"
#include "delay.h"
#define IIC_SDA_1 PDSet(2)
#define IIC_SDA_0 PDReset(2)

#define IIC_SCL_1 PBSet(3)
#define IIC_SCL_0 PBReset(3)

#define READ_SDA PDin(2)

void IIC_Init(void);
void SDA_OUT(void);
void SDA_IN(void);
void IIC_Start(void);
void IIC_Stop(void);
uint8_t IIC_Wait_Ack(void);
void IIC_Ack(void);
void IIC_NAck(void);
void IIC_Send_Byte(uint8_t);
uint8_t IIC_Read_Byte(unsigned char );
float ReadHumidity(void);
float ReadTemperature(void);

#endif

453044814@qq.co · 发表于 2016-6-23 17:23:56

while(1)
{

delay_ms(500);
delay_ms(500);
data = ReadHumidity();
printf("Humi is %2.2f\r\n",data);
delay_ms(500);
delay_ms(500);
data = ReadTemperature();
printf("Temp is %2.2f \r\n",data);
printf("\r\n");
}

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SI7021基于STM32f0

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