ADC问题

yinxiangh 发表于 2023-1-7 09:50

STM8L151K4T6
在一个STM8L151L的最小系统上，用例程测试了芯片的ADC功能，发现测量的数据不怎么稳定，请问正常吗？
ADC程序：
int main( void )
{
   char buf;
   u16 u16_adc1_value;
   float fVal;

   CLK_PeripheralClockConfig (CLK_Peripheral_USART1,ENABLE);                                     //开启ADC/USART时钟
   CLK_PeripheralClockConfig (CLK_Peripheral_ADC1,ENABLE);                                              //开启ADC/USART时钟
   USART_Init(USART1,9600,USART_WordLength_8b,USART_StopBits_1,USART_Parity_No,USART_Mode_Tx);//USART初始化，9600，8N1
   USART_Cmd (USART1,ENABLE);                                                                                                    //使能USART

   /* Enable ADC clock */
   CLK_PeripheralClockConfig(CLK_Peripheral_ADC1, ENABLE);

   /* de-initialize ADC */
   ADC_DeInit(ADC1);

   /*ADC configuration
   ADC configured as follow:
   - Channel VREF
   - Mode = Single ConversionMode(ContinuousConvMode disabled)
   - Resolution = 12Bit
   - Prescaler = /1
   - sampling time 384 */

   ADC_VrefintCmd(ENABLE);
   delay_10us(3);

   ADC_Cmd(ADC1, ENABLE);
   ADC_Init(ADC1, ADC_ConversionMode_Single,
   ADC_Resolution_12Bit, ADC_Prescaler_1);

   ADC_SamplingTimeConfig(ADC1, ADC_Group_FastChannels, ADC_SamplingTime_384Cycles);
   ADC_ChannelCmd(ADC1, ADC_Channel_Vrefint, ENABLE);
   delay_10us(3);

   while(1)
   {
            ADC_SoftwareStartConv (ADC1);//开启软件转换

            while(!ADC_GetFlagStatus (ADC1,ADC_FLAG_EOC));                                                    //等待转换结束
            ADC_ClearFlag (ADC1,ADC_FLAG_EOC);                                                                            //清除对应标志
            u16_adc1_value=ADC_GetConversionValue (ADC1);                                                    //获取转换值

            fVal = 1225;
            fVal *= 4096;
            fVal /= u16_adc1_value;

            sprintf(buf,"VDD = %.1f mV \r\n",fVal);
            USART1_SendStr(buf);
}
}

测量结果通过串口输出：
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3327.3 mV
VDD = 3320.7 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3309.8 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3325.1 mV
VDD = 3318.5 mV
VDD = 3334.0 mV
VDD = 3345.1 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3336.2 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3336.2 mV
VDD = 3336.2 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3336.2 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3345.1 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3309.8 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3318.5 mV
VDD = 3309.8 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3334.0 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3309.8 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3309.8 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3325.1 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3345.1 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3336.2 mV
VDD = 3318.5 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3336.2 mV
VDD = 3320.7 mV
VDD = 3309.8 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3320.7 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3309.8 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3309.8 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3345.1 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3327.3 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3336.2 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3318.5 mV
VDD = 3334.0 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3345.1 mV
VDD = 3318.5 mV
VDD = 3336.2 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3336.2 mV
VDD = 3327.3 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3320.7 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3336.2 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3345.1 mV
VDD = 3318.5 mV
VDD = 3327.3 mV
VDD = 3320.7 mV
VDD = 3336.2 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3336.2 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3345.1 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3340.6 mV
VDD = 3336.2 mV
VDD = 3301.1 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3334.0 mV
VDD = 3340.6 mV
VDD = 3320.7 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3320.7 mV
VDD = 3320.7 mV
VDD = 3318.5 mV
VDD = 3318.5 mV
VDD = 3334.0 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3336.2 mV
VDD = 3338.4 mV
VDD = 3334.0 mV
VDD = 3309.8 mV
VDD = 3318.5 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3334.0 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3338.4 mV
VDD = 3340.6 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3325.1 mV
VDD = 3309.8 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3309.8 mV
VDD = 3340.6 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3320.7 mV
VDD = 3301.1 mV
VDD = 3301.1 mV
VDD = 3329.5 mV
VDD = 3340.6 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3301.1 mV
VDD = 3340.6 mV
VDD = 3320.7 mV
VDD = 3329.5 mV
VDD = 3334.0 mV
VDD = 3338.4 mV
VDD = 3318.5 mV
VDD = 3329.5 mV
VDD = 3318.5 mV
VDD = 3338.4 mV
VDD = 3329.5 mV
VDD = 3329.5 mV
VDD = 3338.4 mV
VDD = 3301.1 mV
......
请问正常吗？

wyjie 发表于 2023-1-7 09:52

用万用表监视VDD电压?

yinxiangh 发表于 2023-1-7 09:54

3325mV，很稳定的

chuxh 发表于 2023-1-7 09:57

如果有空闲，则运行相应的ALM_IDL(), WRN_IDL(), IDL();

dengdc 发表于 2023-1-7 09:59

万用表是短时间取平均值。你用示波器看

renyaq 发表于 2023-1-7 10:00

如果有毛刺就对了，如果有，加一个小电容滤波就可以了

heweibig 发表于 2023-1-7 10:05

硬件是如何连接的呢

gongche 发表于 2023-1-7 10:08

基准电压用的什么

bqyj 发表于 2023-1-7 10:10

直接接地看看采集到的是多少

jiahy 发表于 2023-1-7 10:16

这个波多很正常

jiahy 发表于 2023-1-7 10:17

在没做滤波处理的情况下，这个ADC的采样波动值算正常的。

chuxh 发表于 2023-1-7 10:19

对采样速率进行优化

supernan 发表于 2023-1-7 10:21

可能是基准的问题哦

zwll 发表于 2023-1-7 10:23

用一个恒压源接上看看采样的结果是什么

liliang9554 发表于 2023-1-7 10:26

波动的不是很厉害啊

yinxiangh 发表于 2023-1-7 10:28

其实还是不大明白，我再琢磨琢磨吧，多谢了哈先

tpgf 发表于 2023-2-6 14:24

adc使用的是外部电压基准还是内部电压基准啊

guanjiaer 发表于 2023-2-6 14:31

被采样信号是什么性质的信号啊是不是采样频率不对啊

heimaojingzhang 发表于 2023-2-6 14:46

楼主自己写一个简单的取平均值的滤波算法

keaibukelian 发表于 2023-2-6 15:22

如果这个是原始数据的话应该是还说得通的

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