SC7A20H加速度传感器

使用stm32f103c8 标准库 模拟IIC

#include "stm32f10x.h"
#include "delay.h"

signed short x_buf[32], y_buf[32], z_buf[32];//原始数据
uint8_t fifo_num=0;//缓存个数

#define SC7A20H_READ    0X31
#define SC7A20H_WRITE   0X30


//开漏输出 不用设置方向
#define SC7A20H_SDA_IN() 			   //{GPIOB->CRL &= 0xFFFFFF0F;GPIOB->CRL |=(u32)8<<4;}
#define SC7A20H_SDA_OUT() 			//{GPIOB->CRL &= 0xFFFFFF0F;GPIOB->CRL |=(u32)3<<4;}

//IO操作函数
#define SC7A20H_IIC_SCL				PBout(0)//
#define SC7A20H_IIC_SDA				PBout(1)//输出数据
#define SC7A20H_READ_SDA			PBin(1)//读数据

void SC7A20H_IIC_Start(void)
{
    SC7A20H_SDA_OUT();     //sda线输出
    SC7A20H_IIC_SDA=1;            
    SC7A20H_IIC_SCL=1;
    delay_us(5);
     SC7A20H_IIC_SDA=0;//START:when CLK is high,DATA change form high to low 
    delay_us(6);
    SC7A20H_IIC_SCL=0;//钳住I2C总线，准备发送或接收数据 
}   


void SC7A20H_IIC_Stop(void)
{
    SC7A20H_SDA_OUT();//sda线输出
    SC7A20H_IIC_SCL=0;
    SC7A20H_IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
    SC7A20H_IIC_SCL=1; 
    delay_us(6);
    SC7A20H_IIC_SDA=1;//发送I2C总线结束信号
    delay_us(6);                                   
}
uint8_t SC7A20H_IIC_Wait_Ack(void)
{
    uint8_t tempTime=0;
    SC7A20H_SDA_IN();      //SDA设置为输入  
    SC7A20H_IIC_SDA=1;
    delay_us(1);       
    SC7A20H_IIC_SCL=1;
    delay_us(1);     
    while(SC7A20H_READ_SDA)
    {
        tempTime++;
        if(tempTime>250)
        {
            SC7A20H_IIC_Stop();
            return 1;
        }
    }
    SC7A20H_IIC_SCL=0;//时钟输出0        
    return 0;  
} 
void SC7A20H_IIC_Ack(void)
{
    SC7A20H_IIC_SCL=0;
    SC7A20H_SDA_OUT();
    SC7A20H_IIC_SDA=0;
    delay_us(2);
    SC7A20H_IIC_SCL=1;
    delay_us(5);
    SC7A20H_IIC_SCL=0;
    delay_us(2);
}







void SC7A20H_IIC_NAck(void)
{
    SC7A20H_IIC_SCL=0;
    SC7A20H_SDA_OUT();
    SC7A20H_IIC_SDA=1;
    delay_us(10);
    SC7A20H_IIC_SCL=1;
    delay_us(20);
    SC7A20H_IIC_SCL=0;
    delay_us(10);
} 

void SC7A20H_Send_Byte(uint8_t txd)
{                        
    uint8_t t;   
    SC7A20H_SDA_OUT();         
    SC7A20H_IIC_SCL=0;//拉低时钟开始数据传输
    for(t=0;t<8;t++)
    {              
        if((txd&0x80)>0) //0x80  1000 0000
            SC7A20H_IIC_SDA=1;
        else
            SC7A20H_IIC_SDA=0;
        
        txd<<=1;   
        
        delay_us(2);   //三个延时是必须的
        SC7A20H_IIC_SCL=1;
        delay_us(2); 
        SC7A20H_IIC_SCL=0;    
        delay_us(2);
    }     
} 

uint8_t SC7A20H_Read_Byte(uint8_t ack)
{
    uint8_t i,receive=0;
    SC7A20H_SDA_IN();//SDA设置为输入
    SC7A20H_IIC_SDA = 1;
    
  for(i=0;i<8;i++ )
    {
        SC7A20H_IIC_SCL=1; 
        delay_us(2);

        receive<<=1;
       if(SC7A20H_READ_SDA)receive++;   
        delay_us(1); 
        SC7A20H_IIC_SCL=0;
    }                     
    if (!ack)
        SC7A20H_IIC_NAck();//发送nACK
    else
        SC7A20H_IIC_Ack(); //发送ACK   
    return receive;
}





void SC7A20H_IIC_Init(void)
{

	GPIO_InitTypeDef  GPIO_InitStructure;
 	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);	 
  
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;	 
 	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; 		
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);	  
  
 	GPIO_SetBits(GPIOB,GPIO_Pin_0|GPIO_Pin_1);
    SC7A20H_IIC_SCL=1;
    SC7A20H_IIC_SDA=1;    
}







void SC7A20H_WR_Reg(uint8_t addr,uint8_t val) //地址  值
{
	SC7A20H_IIC_Start();  				 
	SC7A20H_Send_Byte(SC7A20H_WRITE);     	//发送写器件指令   设备地址左移后+0是写 +1是读	 
	SC7A20H_IIC_Wait_Ack();	   
    SC7A20H_Send_Byte(addr);   			//发送寄存器地址
	SC7A20H_IIC_Wait_Ack(); 	 										  		   
	SC7A20H_Send_Byte(val);     		//发送值					   
	SC7A20H_IIC_Wait_Ack();  		    	   
    SC7A20H_IIC_Stop();						//产生一个停止条件 	   

}
uint8_t SC7A20H_RD_Reg(uint8_t addr) 		
{
	uint8_t temp=0;		 
	SC7A20H_IIC_Start();  				 
	SC7A20H_Send_Byte(SC7A20H_WRITE);	//发送写器件指令	 
	temp=SC7A20H_IIC_Wait_Ack();	   
    SC7A20H_Send_Byte(addr);   		//发送寄存器地址
	temp=SC7A20H_IIC_Wait_Ack(); 
	SC7A20H_IIC_Start();  	 	   		//重新启动
	SC7A20H_Send_Byte(SC7A20H_READ);	//发送读器件指令	 
	temp=SC7A20H_IIC_Wait_Ack();	   
    temp=SC7A20H_Read_Byte(0);		//读取一个字节,不继续再读,发送NAK 	    	   
    SC7A20H_IIC_Stop();					//产生一个停止条件 	
	return temp;				//返回读到的值
}


#define SL_SC7A20H_FIFO_CTRL_REG   (unsigned char)0X2E
#define SL_SC7A20H_FIFO_SRC_REG    (unsigned char)0X2F
#define SL_SC7A20H_IIC_OUT_X_L     0x28
#define SL_SC7A20H_IIC_OUT_X_H     0x29
#define SL_SC7A20H_IIC_OUT_Y_L     0x2A
#define SL_SC7A20H_IIC_OUT_Y_H     0x2B
#define SL_SC7A20H_IIC_OUT_Z_L     0x2C
#define SL_SC7A20H_IIC_OUT_Z_H     0x2D

#define SL_SC7A20H_INIT_REG1_NUM 8

static unsigned char SL_SC7A20H_INIT_REG1[SL_SC7A20H_INIT_REG1_NUM*3]=
{
		0x24,0x80,0x00,
    0x2E,0x00,0x00,
    0x1f,0x00,0x00,
    0x20,0x57,0x00,
    0x21,0x70,0x00,   
    0x23,0x30,0x00,
    0x24,0x40,0x00,
    0x2E,0x40,0x00,
};




	unsigned char id1=0;	
	unsigned char id2=0;

signed char SL_SC7A20H_Driver_Init(unsigned char Sl_pull_up_mode)
{
	unsigned char i=0;	

  id1 = SC7A20H_RD_Reg(0x0f);
  id2 = SC7A20H_RD_Reg(0x70);
	
  
  
	if ((id1 != 0x11) || (id2 != 0x28))
 	  return 0;
		

  SC7A20H_WR_Reg(0x57,Sl_pull_up_mode);

  for(i=0;i<SL_SC7A20H_INIT_REG1_NUM;i++)
  {
    SC7A20H_WR_Reg( SL_SC7A20H_INIT_REG1[3*i], SL_SC7A20H_INIT_REG1[3*i+1]);
  }  

  for(i=0;i<SL_SC7A20H_INIT_REG1_NUM;i++)
  {
    SL_SC7A20H_INIT_REG1[3*i+2] = SC7A20H_RD_Reg(SL_SC7A20H_INIT_REG1[3*i]);
  }

  for(i=2;i<SL_SC7A20H_INIT_REG1_NUM;i++)
  {
    if(SL_SC7A20H_INIT_REG1[3*i+1]!=SL_SC7A20H_INIT_REG1[3*i+2]) break;
  }  
  return id2;
}


unsigned char SL_SC7A20H_Read_FIFO_Buf(signed short *x_buf,signed short *y_buf,signed short *z_buf)
{
	unsigned char  i=0;
	unsigned char  sc7a20_data[7];
	unsigned char  SL_FIFO_ACCEL_NUM;

  SL_FIFO_ACCEL_NUM = SC7A20H_RD_Reg(SL_SC7A20H_FIFO_SRC_REG); 
    
	if (SL_FIFO_ACCEL_NUM & 0x40)  
		SL_FIFO_ACCEL_NUM = 32;
	else               
		SL_FIFO_ACCEL_NUM = SL_FIFO_ACCEL_NUM&0x1f;   

for(i = 0; i < SL_FIFO_ACCEL_NUM; i++) {
    sc7a20_data[1] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_X_L); // X_L
    sc7a20_data[2] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_X_H); // X_H
    sc7a20_data[3] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_Y_L); // Y_L
    sc7a20_data[4] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_Y_H); // Y_H
    sc7a20_data[5] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_Z_L); // Z_L
    sc7a20_data[6] = SC7A20H_RD_Reg(SL_SC7A20H_IIC_OUT_Z_H); // Z_H

    x_buf[i] = (signed short)((sc7a20_data[2] << 8) | sc7a20_data[1]);
    y_buf[i] = (signed short)((sc7a20_data[4] << 8) | sc7a20_data[3]);
    z_buf[i] = (signed short)((sc7a20_data[6] << 8) | sc7a20_data[5]);
}

    SC7A20H_WR_Reg(SL_SC7A20H_FIFO_CTRL_REG, 0X00);		
    SC7A20H_WR_Reg(SL_SC7A20H_FIFO_CTRL_REG, 0X4F);

  return SL_FIFO_ACCEL_NUM;
}


int main(void)
{	 
  SystemInit();   //系统时钟初始化
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //   2组中断分组
  delay_init();
  
  SC7A20H_IIC_Init(); //引脚初始化
   SL_SC7A20H_Driver_Init(1);//1是选择内部IIC上拉 ，如果外部接了上拉电阻 可以设置0
  
  while(1)
	{
    fifo_num =SL_SC7A20H_Read_FIFO_Buf(x_buf, y_buf, z_buf);//x_buf是 就是x方向加速度 的缓存了
    delay_ms(100);
	}
}