[嵌入式]stm32 软件IIC

#ifndef __SOFT_IIC_H
#define __SOFT_IIC_H
#include "Sys.h"


#define SDA_IN()  {GPIOB->CRL&=0X0FFFFFFF;GPIOB->CRL|=(u32)8<<28;}
#define SDA_OUT() {GPIOB->CRL&=0X0FFFFFFF;GPIOB->CRL|=(u32)3<<28;}
   
#define IIC_SCL    PBout(6) //SCL
#define IIC_SDA    PBout(7) //outSDA     
#define READ_SDA   PBin(7)  //inSDA 

typedef enum {ACK = 0, NOACK = !ACK} ACKfalg;
#define IS_ACK_PERIPH(ACKx) (((ACKx) == NOACK) || ((ACKx) == ACK))

typedef enum {NOSTOP = 0, STOP = !NOSTOP} STOPflag;
#define IS_STOP_PERIPH(STOPx) (((STOPx) == NOSTOP) || ((STOPx) == STOP))

void IIC_Init(void);
void IIC_Start(void);
ACKfalg IIC_Send_Byte(u8 txd, STOPflag STOPx);
u8 IIC_Read_Byte(ACKfalg ACKx);

#endif

.c文件

#include "soft_IIC.h"


void IIC_Init(void)
{     
	Delay_Init();                    
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE );    
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ;   
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    IIC_SCL=1;
    IIC_SDA=1;

}

void IIC_Start(void)
{
    SDA_OUT();     
    IIC_SDA=1;            
    IIC_SCL=1;
    delay_us(4);
    IIC_SDA=0;
    delay_us(4);
    IIC_SCL=0;
}      

void IIC_Stop(void)
{
    SDA_OUT();
    IIC_SCL=0;
    IIC_SDA=0;
    delay_us(4);
    IIC_SCL=1; 
    delay_us(4); 	
    IIC_SDA=1;
    delay_us(4);                                   
}
ACKfalg IIC_Wait_Ack(void){
	u8 ucErrTime=0;	
	IIC_SDA=1; 
    SDA_IN(); 	
    IIC_SCL=1;  
    while(READ_SDA)
    {
        ucErrTime++;
        if(ucErrTime>250)
        {
            IIC_Stop();
            return NOACK;
        }
    }
    IIC_SCL=0;        
    return ACK;
}

ACKfalg IIC_Send_Byte(u8 txd, STOPflag STOPx)
{                        
    u8 t; 
	assert_param(IS_STOP_PERIPH(STOPx));
    SDA_OUT();         
    IIC_SCL=0;
    for(t=0;t<8;t++)
    {              
        IIC_SDA=(txd&0x80)>>7;
        txd<<=1;       
        delay_us(2);  
        IIC_SCL=1;
        delay_us(4); 
        IIC_SCL=0;    
        delay_us(2);
    }
	if(STOPx){
		if(IIC_Wait_Ack()){
			return NOACK;
		}
		IIC_Stop();
		return ACK;
	}
    return IIC_Wait_Ack();
} 


void IIC_Ack(void)
{
    IIC_SCL=0;
    SDA_OUT();
    IIC_SDA=0;
    delay_us(2);
    IIC_SCL=1;
    delay_us(4);
    IIC_SCL=0;
}

void IIC_NAck(void)
{
    IIC_SCL=0;
    SDA_OUT();
    IIC_SDA=1;
    delay_us(2);
    IIC_SCL=1;
    delay_us(4);
    IIC_SCL=0;
}  

u8 IIC_Read_Byte(ACKfalg ACKx)
{
    unsigned char i,receive=0;
	assert_param(IS_ACK_PERIPH(ACKx));
    SDA_IN();
    for(i=0;i<8;i++ )
    {
        IIC_SCL=0; 
        delay_us(4);
        IIC_SCL=1;
        receive<<=1;
		delay_us(1);
        if(READ_SDA)receive|=0x01;
    }                     
    if (ACKx){
		IIC_NAck();
		IIC_Stop();
	}

    else{
		IIC_Ack();
	} 
    return receive;
}