八路adc采集结果不稳定

发布于 2022-09-04 13:49:15 浏览：529 订阅该版

```
#define ADC_DEV_NAME        "adc1"      /* ADC 设备名称 */
#define ADC_DEV_CHANNEL_PA0     0           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PA1     1           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PA4     4           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PA5     5           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PA6     6           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PA7     7           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PB0     8           /* ADC 通道 */
#define ADC_DEV_CHANNEL_PB1     9           /* ADC 通道 */
#define REFER_VOLTAGE       330         /* 参考电压 3.3V,数据精度乘以100保留2位小数*/
#define CONVERT_BITS        (1 << 12)   /* 转换位数为12位 */

//创建adc采集线程
rt_thread_t Adc_thread = RT_NULL;

static void Adc_entry(void* paremeter)
{
    rt_adc_device_t adc_dev;
    rt_uint32_t adc1_value,adc1_vol,adc2_value,adc2_vol,adc3_value,adc3_vol,adc4_value,adc4_vol;
    rt_uint32_t adc5_value,adc5_vol,adc6_value,adc6_vol,adc7_value,adc7_vol,adc8_value,adc8_vol;
    rt_err_t ret;

adc_dev = (rt_adc_device_t)rt_device_find(ADC_DEV_NAME);
    if (adc_dev == RT_NULL)
    {
        rt_kprintf("adc sample run failed! can't find %s device!\n", ADC_DEV_NAME);
    }
    /* 使能设备*/
    ret= rt_adc_enable(adc_dev, ADC_DEV_CHANNEL_PA0|ADC_DEV_CHANNEL_PA1|ADC_DEV_CHANNEL_PA4|ADC_DEV_CHANNEL_PA5|ADC_DEV_CHANNEL_PA6|ADC_DEV_CHANNEL_PA7|ADC_DEV_CHANNEL_PB0|ADC_DEV_CHANNEL_PB1);
    if(ret == RT_EOK)
    {
        rt_kprintf("adc sample run success!  find %s device!\n", ADC_DEV_NAME);
    }
    rt_thread_mdelay(1000);
    while(1)
    {
        /* 读取采样值 */
        adc1_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA0);
        /* 转换为对应电压值 */
        adc1_vol = adc1_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc1_voltage is :%d.%02d \n", adc1_vol / 100, adc1_vol % 100);

adc2_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA1);
        adc2_vol = adc2_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc2_voltage is :%d.%02d \n", adc2_vol / 100, adc2_vol % 100);

adc3_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA4);
        adc3_vol = adc3_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc3_voltage is :%d.%02d \n", adc3_vol / 100, adc3_vol % 100);

adc4_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA5);
        adc4_vol = adc4_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc4_voltage is :%d.%02d \n", adc4_vol / 100, adc4_vol % 100);

adc5_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA6);
        adc5_vol = adc5_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc5_voltage is :%d.%02d \n", adc5_vol / 100, adc5_vol % 100);

adc6_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PA7);
        adc6_vol = adc6_value * REFER_VOLTAGE / CONVERT_BITS;
        rt_kprintf("the adc6_voltage is :%d.%02d \n", adc6_vol / 100, adc6_vol % 100);

adc7_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PB0);
         adc7_vol = adc7_value * REFER_VOLTAGE / CONVERT_BITS;
         rt_kprintf("the adc7_voltage is :%d.%02d \n", adc7_vol / 100, adc7_vol % 100);

adc8_value= rt_adc_read(adc_dev, ADC_DEV_CHANNEL_PB1);
         adc8_vol = adc8_value * REFER_VOLTAGE / CONVERT_BITS;
         rt_kprintf("the adc8_voltage is :%d.%02d \n", adc8_vol / 100, adc8_vol % 100);

rt_thread_delay(500);
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int app_ADC_init(void)
{
    Adc_thread = rt_thread_create("adc1",
             Adc_entry,
             RT_NULL,
             THREAD_STACK_SIZE*4,
             THREAD_PRIORITY-20,
             THREAD_TIMESLICE*2);
     if(Adc_thread != RT_NULL)
         {
             rt_thread_startup(Adc_thread);
         }
     return RT_EOK;
}

INIT_APP_EXPORT(app_ADC_init);
```

数据采集过程中adc的值移植不稳定，三路3.3v，5路0v，采集的结果如图

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20220904/7472111ca270b183c398985004357064.png)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20220904/b98368f46f9f20fa72fb4dc5578dc6db.png)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20220904/4bcf6073e870d68f2eaf4d54cba0c3a0.png)