ADC芯片3421驱动程序

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#ifndef MCP3421_H
#define MCP3421_H
#include "common.h"

typedef enum mcp_div
{
    mcp_div_12 = 0,
    mcp_div_14,
    mcp_div_16,
    mcp_div_18,
}mcp_div_e;
typedef enum mcp_amp
{
    mcp_amp_x1 = 0,
    mcp_amp_2,
    mcp_amp_4,
    mcp_amp_8,
}mcp_amp_e;

//获取ADC转换结果
float mcp3421_get_val();


//int mcp3421_set(u8 div,u8 amp);
int mcp3421_set(mcp_div_e div,mcp_amp_e amp);
int mcp3421_wr_data(unsigned char data);
unsigned int mcp3421_rd_data();
u8 mcp3421_config_data();
int select_res(char sw,char num);



#endif

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#include "mcp3421.h"
#include "myiic.h"
#include "main.h"

#define VOL_REF   (2.048*2)
#define MAX_18BIT (0x3FFFF)
#define MAX_16BIT (0xFFFF)
#define MAX_14BIT (0x3FFF)
#define MAX_12BIT (0xFFF)
u8 mcp_busy = 0;
static mcp_div_e mcp_div =  mcp_div_12;
static mcp_amp_e mcp_amp = mcp_amp_x1;
u32 mcp_data = 0;
//获取ADC转换为电压的结果
float mcp3421_get_val()
{
    
    
    mcp_data = 0xFFFFFFFF;
    do
    {
        mcp_data = mcp3421_rd_data();
    }while(mcp_data == 0xFFFFFFFF);
//    if(mcp_data != 0xFFFFFFFF)
    
      switch(mcp_div)
      {
          case mcp_div_18:
            return  VOL_REF*mcp_data/MAX_18BIT;
            break;
            
          case mcp_div_16:
            //mcp_data -= 100;
            return VOL_REF*mcp_data/MAX_16BIT;
            break;
            
          case mcp_div_14:
            return VOL_REF*mcp_data/MAX_14BIT;
            break;
            
          case mcp_div_12:
            return VOL_REF*mcp_data/MAX_12BIT;
            break;
            
          default:
            return -1;
            break;
      }
//    else
//      return -1;
    
  
}




float mcp3421_get_ad_avg(int times)
{
    float ad_data=0;
    while(times--)
    {
        ad_data = mcp3421_get_val();
    }
    
    return ad_data/times;
}
//设置分辨率和输入端放大倍数
/*
div:
0 :12bit  240 SPS
1 :14bit  60 SPS
2 :16bit  15 SPS
3 :18bit  3.75 SPS
amp:
0 :x1
1 :x2
2 :x4
3 :x8
*/
u8 reg = 0;
int mcp3421_set(mcp_div_e div,mcp_amp_e amp)
{
  
  if(div < 4 && amp < 4)
  {
    reg=(div<<2)+0x90;
    reg += amp&0x03;
    mcp3421_wr_data(reg);
    mcp_div = div;
    mcp_amp = amp;
  }
    return 0;
}


//向MCP3421写入一字节数据
static int mcp3421_wr_data(unsigned char data)
{
  int ack = 1;
  IIC_Start();                           //启动总线
  IIC_Send_Byte(0xD0);                    //发送器件地址
  ack = IIC_Wait_Ack();
  IIC_Send_Byte(data);                   //发送器件分地址
  ack = IIC_Wait_Ack();
  IIC_Stop();                            //释放总线
  
  return ack;
    
}
//返回采样数据

//读取成功：返回ADC原始数值
//失败返回：0xFFFFFFFF
unsigned int mcp3421_rd_data()
{
    u8 elec1, elec2, elec3;
    IIC_Start();                           //启动总线
    IIC_Send_Byte(0xD1);                    //发送器件地址
    IIC_Wait_Ack();
    elec1 = IIC_Read_Byte(1); 
    elec2 = IIC_Read_Byte(1); 
    elec3 = IIC_Read_Byte(1); 
    
    mcp_busy = IIC_Read_Byte(0);
    IIC_Stop();              //释放总线
//    debug_info("MCP3241 data:rn");
//    debug_info("B1:%xrn",elec1);
//    debug_info("B2:%xrn",elec2);
//    debug_info("B3:%xrn",elec3);
//    debug_info("BUSY:%xrn",mcp_busy);
    if(mcp_div == mcp_div_18)
    {    
        if((mcp_busy & 0x80) == 0x80)//(mcp_busy & 0x80) == 0x80
        {
            return 0xFFFFFFFF;
        }
    }
    else
    {
        if((elec3 & 0x80) == 0x80)//(mcp_busy & 0x80) == 0x80
        {
            return 0xFFFFFFFF;
        }
        
    }   
    
      switch(mcp_div)
      {
          case mcp_div_18:
            return ((u32)((u32)elec1 << 16 | (u32)elec2 << 8 | elec3)) & 0x03FFFF;
            break;
            
          case mcp_div_16:
            return ((u32)((u32)elec1 << 8 | (u32)elec2 )) & 0xFFFF;
            break;
            
          case mcp_div_14:
            return ((u32)((u32)elec1 << 8 | (u32)elec2 )) & 0x3FFF;
            break;
            
          case mcp_div_12:
            return ((u32)((u32)elec1 << 8 | (u32)elec2 )) & 0xFFF;
            break;
            
          default:
            return 0xFFFFFFFF;
            break;
      }
    
    
}

u8 mcp3421_config_data()
{
    mcp3421_rd_data();
    return mcp_busy;
}