圣龙扬特-AVR电子

标题: AVR读取ADS7805 16位ADC子函数 [打印本页]

作者: sunany 时间: 2013-3-3 22:19
标题: AVR读取ADS7805 16位ADC子函数
功能：取ADS7805的16位AD转换值，同时将转换来的值转成-2--+2
//---------------------------------------
//This procedure is prepared for the ADS7805 for AD convertion
//Charge the PIN definition for your configration.
//The procedure is complied under ICCAVR.
//ADC_init();ADC_to_um(void) must be do;
//Author：Sunany
//Date：2010-12-1
//-----------------------------------------
#define RC_DIR_OUT    DDRD|=BIT(4)
#define RC_H          PORTD|=BIT(4)
#define RC_L          PORTD&=~BIT(4)
#define BYTE_DIR_OUT    DDRD|=BIT(5)
#define BYTE_H          PORTD|=BIT(5)
#define BYTE_L          PORTD&=~BIT(5)
#define BUSY_DIR_IN    DDRD&=~BIT(6)
#define BUSY_H          PORTD|=BIT(6)
#define BUSY_read       (PIND&0x40)       //Get ADC Busy or not
#define Data_port1_IN DDRC&=0xC0       //BIT 0-BIT 5 is PC0-PC5
#define Data_port2_IN DDRD&=0xF3       //Bit 6 is PD2，BIT 7 is PD3
#define Data_port       ( (PINC & 0x3F) | ((PIND&0x0C) << 4) )
void ADS7805_init(void)
{
RC_DIR_OUT;
RC_H;
BYTE_DIR_OUT;
BYTE_H;
BUSY_DIR_IN;
Data_port1_IN;
Data_port2_IN;
}
uint Start_ADC(void)
{
uint ADC_tempH=0;
uint ADC_tempL=0;
uchar conv_ok=0;

RC_L;
asm("nop");
RC_H;
delay_us(6);
conv_ok=1;
if(BUSY_read==0)
{
   delay_us(2);
  if(BUSY_read==0)
  {
   conv_ok=0;
  }
}

if(conv_ok==1)
{
   asm("nop");
   BYTE_L;
  delay_us(1);
   ADC_tempH=Data_port;

   BYTE_H;
      delay_us(1);
   ADC_tempL=Data_port;

  ADC_tempH=(ADC_tempH<<8)+ADC_tempL;
}
return(ADC_tempH);
}
signed int Avg_ADC(signed int *data )
{
uchar count,i,j;
signed int  value_buf[12];
signed int  temp;
signed long sum=0;

for (count=0;count<12;count++)
{
      value_buf[count] =data[count];
}

for (j=0;j<11;j++)
{
      for (i=0;i<11-j;i++)
      {
         if ( value_buf[i]>value_buf[i+1] )
         {
            temp = value_buf[i];
            value_buf[i] = value_buf[i+1];
            value_buf[i+1] = temp;
         }
      }
}
for(count=2;count<10;count++)
sum += value_buf[count];
return( (signed int)(sum>>3) );
}
signed int AD_conversion(void)
{
uchar j;
signed int temp;
signed int ADC0_temp[12]={0};

for(j=0;j<12;j++)
{
  ADC0_temp[j]=Start_ADC();
  delay_us(1);
}
temp=Avg_ADC(ADC0_temp);
return(temp);
}
signed int ADC_to_um(void)
{
signed long ADC_data_temp;
ADC_data_temp=AD_conversion();
ADC_data_temp=(signed int)(ADC_data_temp*0.62);  //固定系数，按2mm对应32768得到
if( ADC_data_temp> 20000 )
{
   ADC_data_temp=20000;
}
if( ADC_data_temp<-20000 )
{
   ADC_data_temp=-20000;
}
return (ADC_data_temp);
}
//较准用测量函数
signed int ADC_Calib_um(signed int stander,signed int calib)
{
signed long ADC_data_temp;
ADC_data_temp=AD_conversion();
ADC_data_temp=(signed int)( (ADC_data_temp-calib)*0.62 )+stander;  //计算校准后值
  return (ADC_data_temp);
}

作者: 箫天 时间: 2013-3-3 22:52
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作者: ulpte 时间: 2013-3-17 19:28
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作者: zouchangchun 时间: 2013-4-11 19:59
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