stm32f407adc定时器触发采样库函数代码

以下是一个基于STM32F407的ADC定时器触发采样的库函数代码示例：

#include "stm32f4xx.h"

// 定义ADC采样变量以及DMA缓存区
volatile uint16_t ADC_Value[16];
volatile uint16_t DMA_Buffer[16];

// 初始化ADC的函数
void ADC_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    ADC_CommonInitTypeDef ADC_CommonInitStructure;
    ADC_InitTypeDef ADC_InitStructure;
    DMA_InitTypeDef DMA_InitStructure;
    TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    TIM_OCInitTypeDef TIM_OCInitStructure;

    // 使能ADC和DMA时钟
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2 | RCC_AHB1Periph_GPIOA, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    // 初始化DMA
    DMA_InitStructure.DMA_Channel = DMA_Channel_0;
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)DMA_Buffer;
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
    DMA_InitStructure.DMA_BufferSize = 16;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    DMA_Init(DMA2_Stream0, &DMA_InitStructure);
    DMA_Cmd(DMA2_Stream0, ENABLE);

    // 初始化GPIO
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // 初始化ADC
    ADC_CommonInitStructure.ADC_Mode = ADC_Mode_Independent;
    ADC_CommonInitStructure.ADC_Prescaler = ADC_Prescaler_Div2;
    ADC_CommonInitStructure.ADC_DMAAccessMode = ADC_DMAAccessMode_Disabled;
    ADC_CommonInitStructure.ADC_TwoSamplingDelay = ADC_TwoSamplingDelay_5Cycles;
    ADC_CommonInit(&ADC_CommonInitStructure);

    ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
    ADC_InitStructure.ADC_ScanConvMode = ENABLE;
    ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
    ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_Rising;
    ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_TRGO;
    ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
    ADC_InitStructure.ADC_NbrOfConversion = 8;
    ADC_Init(ADC1, &ADC_InitStructure);

    ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 5, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 6, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 7, ADC_SampleTime_15Cycles);
    ADC_RegularChannelConfig(ADC1, ADC_Channel_7, 8, ADC_SampleTime_15Cycles);

    ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);
    ADC_DMACmd(ADC1, ENABLE);
    ADC_Cmd(ADC1, ENABLE);

    // 初始化定时器，设置为1kHz的频率
    TIM_TimeBaseStructure.TIM_Period = 840 - 1;
    TIM_TimeBaseStructure.TIM_Prescaler = 100 - 1;
    TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

    // 初始化定时器OC
    TIM_OCStructInit(&TIM_OCInitStructure);
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = 420 - 1;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM2, &TIM_OCInitStructure);

    TIM_SelectOutputTrigger(TIM2, TIM_TRGOSource_Update);
    TIM_Cmd(TIM2, ENABLE);
}

// 获取ADC采样值
uint16_t ADC_GetValue(uint8_t ch)
{
    uint16_t value = 0;

    if (ch < 8) {
        value = ADC_Value[ch];
    }

    return value;
}

// DMA传输完成中断处理函数
void DMA2_Stream0_IRQHandler(void)
{
    if(DMA_GetITStatus(DMA2_Stream0, DMA_IT_TCIF0)) {
        DMA_ClearITPendingBit(DMA2_Stream0, DMA_IT_TCIF0);
    }
}

// 主函数
int main(void)
{
    ADC_Init();

    while (1) {
        // 定时器触发采样
        ADC_SoftwareStartConv(ADC1);

        // 等待DMA传输完成
        while(!DMA_GetFlagStatus(DMA2_Stream0, DMA_FLAG_TCIF0));

        // 复制DMA缓存区数据到ADC采样变量
        for (int i = 0; i < 8; i++) {
            ADC_Value[i] = DMA_Buffer[i];
        }

        // 清除DMA传输完成标志位
        DMA_ClearFlag(DMA2_Stream0, DMA_FLAG_TCIF0);
    }
}

在上述示例代码中，我们使用了定时器2作为ADC的外部触发源，并且将其配置为1kHz的频率。在每次定时器溢出时，定时器会触发一次ADC采样。我们使用DMA来传输ADC采样值，这样可以减少CPU的负担，并且提高采样速度。在DMA传输完成后，我们将DMA缓存区的数据复制到ADC采样变量中，然后等待下一次定时器触发采样。