STM8S103 ADC存在问题

我正在使用STM8S103测量分别命名为vs12，vs5和vs3的三个电压信号通道。定时器4使能每10ms产生一次中断，并交替测量三个电压信号。也就是说，在第1个10ms中断中，测量vs12。在第二个10ms中断中，测量vs5。在第3个10ms中断中，测量vs3，依此类推。在每次测量期间，mcu进行16次捕获以进行进一步的平均处理。测量结果将通过UART显示在超级终端中。


问题是当只启用1个通道（vs12，vs5或vs3）时，测量是正确的。但是当启用两个通道时，两个通道的测量都是错误的。谁能看看下面的代码并给我一些建议？

C代码描述如下。
主要（）
{
ADC1-> CR1 | =（ADC1_CR1_SPSEL＆amp;（0x02  CR2 | = ADC1_CR2_ALIGN; //正确的对齐

而（1）{
//选择ADC通道
if（vs_sel == 0）{
ADC1-> CSR | =（ADC1_CSR_CH＆amp; CH_VS12）;
} else if（vs_sel == 1）{
ADC1-> CSR | =（ADC1_CSR_CH＆amp; CH_VS5）;
}
}
}

定时器4中断：
@far @interrupt void irq_system_tim4_ovf（void）
{
//如果采用MAX NO OF OF Sample采样电压
//值不会记录在数组vs12_arr中
no_of_sample_vals = 0;
while（no_of_sample_vals＆lt; MAX_NO_SAMPLE_VAL）
{
//启动ADC
ADC1-> CR1 | = ADC1_CR1_ADON; // ADC启动
ADC1-> CR1 | = ADC1_CR1_ADON; //开始转换
//检查EOC
while（！（ADC1-＆gt; CSR＆amp; ADC1_CSR_EOC））{};
//必须先读LSB
if（vs_sel == 0）{
vs12_arr [no_of_sample_vals] = ADC1-＆gt; DRL;
vs12_arr [no_of_sample_vals] | = ADC1-＆gt; DRH＆lt;＆lt; 8;
} else if（vs_sel == 1）{
vs5_arr [no_of_sample_vals] = ADC1-＆gt; DRL;
vs5_arr [no_of_sample_vals] | = ADC1-＆gt; DRH＆lt;＆lt; 8;
}
// ADC断电
ADC1-> CR1 | = ~ADC1_CR1_ADON;

no_of_sample_vals ++;
}
//更新时间计数器
flag_10ms = 1;
if（t_10ms == 100）{/ * 1秒完成* /
flag_1sec = 1;
t_10ms = 0;
}
T_10MS ++;
vs_sel ++;
if（vs_sel == 3）vs_sel = 0;
//清除旗帜
TIM4-> SR1＆amp; =〜（0x01）;
返回;
}



以下为原文




I am using STM8S103 to measure three channels of voltage signals named vs12, vs5 and vs3 respectively. Timer 4 is enabled to generate interrupt every 10ms and three voltage signals are measured alternately. That is, in the 1st 10ms interrupt, vs12 is measured. In the 2nd 10ms interrupt, vs5 is measured. In the 3rd 10ms interrupt, vs3 is measured, and so on. During each measurement, mcu makes 16 captures for further average processing. The measurement result will be displayed in HyperTerminal via UART.


The problem is that when only 1 channel (vs12, vs5, or vs3) is enabled, the measurement is correct. But when two channels are enabled, both channels' measurements are wrong. Could anyone have a look at the following code and give me some suggestions?

The C code is described as follows.
main()
{
      ADC1->CR1 |= (ADC1_CR1_SPSEL & (0x02<<4)); //fADC = 4 MHz
      ADC1->CR2 |= ADC1_CR2_ALIGN; //right aligment
      
     while(1){
           // select the ADC channel
           if (vs_sel==0){
ADC1->CSR |= (ADC1_CSR_CH & CH_VS12);  
} else if (vs_sel==1){
ADC1->CSR |= (ADC1_CSR_CH & CH_VS5);
}
    }
}

Timer 4 Interrupt:
@far @interrupt void irq_system_tim4_ovf (void)
{
  // If MAX NO OF SAMPLES are taken then voltage
// values will not be recorded in array vs12_arr
no_of_sample_vals = 0;
while( no_of_sample_vals < MAX_NO_SAMPLE_VAL )  
{                                             
//start ADC
ADC1->CR1 |= ADC1_CR1_ADON; //ADC powered up
ADC1->CR1 |= ADC1_CR1_ADON; //begin conversion  
//check for the EOC
while (!(ADC1->CSR & ADC1_CSR_EOC)){};  
//must read LSBs first
if (vs_sel==0){
vs12_arr[no_of_sample_vals] = ADC1->DRL;  
vs12_arr[no_of_sample_vals] |= ADC1->DRH << 8;
} else if (vs_sel==1){
vs5_arr[no_of_sample_vals] = ADC1->DRL;  
vs5_arr[no_of_sample_vals] |= ADC1->DRH << 8;
}
//ADC powered down
ADC1->CR1 |= ~ADC1_CR1_ADON;  
  
no_of_sample_vals++;
}
// Update the time counter
flag_10ms = 1;
if (t_10ms==100){  /* 1 sec is completed */
  flag_1sec = 1;
t_10ms = 0;
}
t_10ms++;
vs_sel++;
if (vs_sel==3) vs_sel = 0;
// Clear the flag
    TIM4->SR1 &=~(0x01);
    return;
}