ADC - 电压采集

本篇总结

使用 ADC + DMA，采集模拟电压并串口打印。

硬件平台：本例程基于 W55MH32L-EVB 开发板运行。

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void UART_Configuration(void)
{
    GPIO_InitTypeDef  GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);

    /* PA9: USART1_TX → 复用推挽输出 */
    GPIO_InitStructure.GPIO_Pin   = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* PA10: USART1_RX → 浮空输入 */
    GPIO_InitStructure.GPIO_Pin  = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* USART 参数：115200 / 8N1 / 全双工 */
    USART_InitStructure.USART_BaudRate            = 115200;
    USART_InitStructure.USART_WordLength          = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits            = USART_StopBits_1;
    USART_InitStructure.USART_Parity              = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode                = USART_Mode_Rx | USART_Mode_Tx;

    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
}

void ADC_Configuration(void)
{
    uint32_t         i;
    ADC_InitTypeDef  ADC_InitStructure;
    GPIO_InitTypeDef GPIO_InitStructure;

    /* 使能 GPIOA 和 ADC1 时钟 */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_ADC1, ENABLE);

    /* PA6: 模拟输入模式 */
    GPIO_InitStructure.GPIO_Pin   = ADC_TEST_CHANNEL_PIN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AIN;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* ADC 时钟：PCLK2 的 8 分频 */
    RCC_ADCCLKConfig(RCC_PCLK2_Div8);
    ADC_DeInit(ADC1);

    /* ADC 参数：独立模式 / 扫描 / 单次转换 / 软件触发 / 右对齐 */
    ADC_InitStructure.ADC_Mode               = ADC_Mode_Independent;
    ADC_InitStructure.ADC_ScanConvMode       = ENABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStructure.ADC_ExternalTrigConv   = ADC_ExternalTrigConv_None;
    ADC_InitStructure.ADC_DataAlign          = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfChannel       = CONV_CHANNEL_NUM;
    ADC_Init(ADC1, &ADC_InitStructure);

    /* 配置规则通道：通道6，转换顺序1，采样时间239.5周期 */
    for (i = 0; i < CONV_CHANNEL_NUM; i++)
    {
        ADC_RegularChannelConfig(ADC1, ADC_CovChannel[i], i + 1, ADC_SampleTIME[i]);
    }

    ADC_SoftwareStartConvCmd(ADC1, ENABLE);
    ADC_Cmd(ADC1, ENABLE);

    /* ADC 校准（必须步骤） */
    ADC_ResetCalibration(ADC1);
    while (ADC_GetResetCalibrationStatus(ADC1));
    ADC_StartCalibration(ADC1);
    while (ADC_GetCalibrationStatus(ADC1));

    /* 配置 DMA 搬运转换结果 */
    DMA_Configuration();
}

如果你想自定义

• 换采集通道 → 修改 ADC_CovChannel[] 数组和对应的 GPIO 引脚，如改为 ADC_Channel_0 对应 PA0
• 改采样精度 → 修改 ADC_SampleTIME[]，可选 1.5/7.5/13.5/28.5/41.5/55.5/71.5/239.5 周期，周期越长精度越高
• 改为连续转换 → 将 ADC_ContinuousConvMode 设为 ENABLE，ADC 会自动连续转换，无需软件反复触发

void DMA_Configuration(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;
    DMA_InitTypeDef  DMA_InitStructure;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
    DMA_DeInit(DMA1_Channel1);

    /* 外设地址：ADC1 数据寄存器 */
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
    /* 内存地址：存储数组 */
    DMA_InitStructure.DMA_MemoryBaseAddr     = (uint32_t)DAM_ADC_Value;
    /* 方向：外设 → 内存 */
    DMA_InitStructure.DMA_DIR                = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize         = CONV_CHANNEL_NUM;
    DMA_InitStructure.DMA_PeripheralInc      = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc          = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
    DMA_InitStructure.DMA_MemoryDataSize     = DMA_MemoryDataSize_Word;
    /* 循环模式：完成一次后自动重新开始 */
    DMA_InitStructure.DMA_Mode               = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority           = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M                = DMA_M2M_Disable;

    DMA_Init(DMA1_Channel1, &DMA_InitStructure);
    DMA_Cmd(DMA1_Channel1, ENABLE);
    ADC_DMACmd(ADC1, ENABLE);

    /* 配置 DMA 传输完成中断 */
    NVIC_InitStructure.NVIC_IRQChannel                   = DMA1_Channel1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority        = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd                = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    DMA_ITConfig(DMA1_Channel1, DMA1_IT_TC1, ENABLE);
}

void DMA1_Channel1_IRQHandler(void)
{
    if (DMA_GetITStatus(DMA1_IT_TC1) != RESET)
    {
        DMA_ClearITPendingBit(DMA1_IT_TC1);
        DMA_ClearFlag(DMA1_FLAG_TC1);

        /* 打印原始码值和换算电压值 */
        printf("Code Value = %d ,voltage value = %2.4f\n", DAM_ADC_Value[0],
               (float)VREF * DAM_ADC_Value[0] / 4095 / 1000);
    }
}

如果你想自定义

• 改参考电压 → 修改 VREF 宏定义，如外部参考电压为 3.0V 则设为 3000
• 多通道采集 → 增大 CONV_CHANNEL_NUM，在 ADC_CovChannel[] 中添加更多通道，中断中遍历数组打印每个通道的值

int SER_PutChar(int ch)
{
    while (!USART_GetFlagStatus(USART1, USART_FLAG_TC));
    USART_SendData(USART1, (uint8_t)ch);
    return ch;
}

int fputc(int c, FILE *f)
{
    if (c == '\n')
        SER_PutChar('\r');         // 补回车，确保串口工具正确换行
    return (SER_PutChar(c));
}

int main(void)
{
    RCC_ClocksTypeDef clocks;
    delay_init();

    UART_Configuration();
    RCC_GetClocksFreq(&clocks);

    printf("\n");
    printf("SYSCLK: %3.1fMhz, HCLK: %3.1fMhz, PCLK1: %3.1fMhz, "
           "PCLK2: %3.1fMhz, ADCCLK: %3.1fMhz\n",
           (float)clocks.SYSCLK_Frequency / 1000000,
           (float)clocks.HCLK_Frequency / 1000000,
           (float)clocks.PCLK1_Frequency / 1000000,
           (float)clocks.PCLK2_Frequency / 1000000,
           (float)clocks.ADCCLK_Frequency / 1000000);
    printf("ADC Single Test\n");

    ADC_Configuration();

    while (1)
    {
        /* 软件触发 ADC 转换，每秒一次 */
        ADC_SoftwareStartConvCmd(ADC1, ENABLE);
        delay_ms(1000);
    }
}

如果你想自定义

• 改采集频率 → 修改 delay_ms() 的参数，如 delay_ms(100) 为每 100ms 采集一次
• 使用定时器触发 → 将 ADC_ExternalTrigConv 改为定时器触发源（如 ADC_ExternalTrigConv_T1_CC1），实现精确定时采集