STM8L051，AD值误差大

keed 提问时间：2015-2-5 10:06 /

问答
是否解决:

悬赏7ST金币未解决

金币全给了，不要嫌少，问题如下

前段时间在使用STM8S在一个锂电池管理项目上，但是发现给MCU供电不是很好处理，故改用STM8L051 发现一个比较奇怪的问题！
单独转换通道 AD值还是比较准确的，但是4个通道轮番扫描一次就，AD值就有比较大的误差，程序如下
  程序放在中断里面，无关部分省略…………
  for(ADCCH=0;ADCCH<4;)
  {
   if(ADCCH == 0)
   {
      InputTep = InputTep + ADC_CONV(ADCCH);
   }
if(ADCCH == 1)
   {
      BattTep = BattTep + ADC_CONV(ADCCH);
   }
if(ADCCH == 2)
   {
      VBusTep = VBusTep + ADC_CONV(ADCCH);
   }
if(ADCCH == 3)
   {
      LoadCurrTep = LoadCurrTep + ADC_CONV(ADCCH);
   }
ADCCH++;
  }
  ADCCNT++;
  if(ADCCNT == 8)
  {
InputAVGOld = InputAVG;
BattAVGOld = BattAVG;
VBusAVGOld = VBusAVG;
LoadCurrAVGOld = LoadCurrAVG;
InputAVG = InputTep>>3;
BattAVG = BattTep>>3;
VBusAVG = VBusTep>>3;
LoadCurrAVG = LoadCurrTep>>3;
InputTep = 0;
BattTep = 0;
VBusTep = 0;
LoadCurrTep = 0;
ADCCNT = 0;

}

void Init_AD(void)
{
            ADC1_CR2 = 0x83;
            ADC1_CR3 = 0x80;
            ADC1_SQR1 = 0x80;
            ADC1_SQR2 = 0;
            ADC1_SQR4 = 0;
}

unsigned int ADC_CONV(unsigned char ADCH)
{
unsigned int DataTep;
unsigned int DataTep1;
ADC1_SQR3 = 0x08<<ADCH;
ADC1_CR1|=0x02;
while(ADC1_SR_EOC == 0);
DataTep = ADC1_DRL;
DataTep1 = ADC1_DRH;
DataTep1 = DataTep1<<8;
DataTep = DataTep|DataTep1;
ADC1_SR_EOC = 0;
ADC1_SQR3 = 0;
return DataTep;
}