无法在STM32上使用DAC和DMA生成正弦波

Question

我在使用 STM32F303K8 nucleo 板生成正弦波时遇到问题。在我看来，一切都按应有的方式配置，但我可以在示波器上看到 gnd，因此它不起作用。也许有人知道为什么？ 代码如下:

#include "stm32f30x.h"
#include <stdio.h>

#define DAC_DHR12R2_ADDRESS      0x40007414

const uint16_t Sine12bit[32] = {
    2047, 2447, 2831, 3185, 3498, 3750, 3939, 4056, 4095, 4056,
    3939, 3750, 3495, 3185, 2831, 2447, 2047, 1647, 1263,  909,
     599,  344,  155,   38,    0,   38,  155,  344,  599,  909,
     263, 1647};

DAC_InitTypeDef             DAC_InitStructure;
DMA_InitTypeDef             DMA_InitStructure;
GPIO_InitTypeDef            GPIO_InitStructure;
TIM_TimeBaseInitTypeDef     TIM_TimeBaseStructure;

static void DMA_setup(void){
    DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR12R2_ADDRESS;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&Sine12bit;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = 32;
    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_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel1, &DMA_InitStructure);
    DMA_Cmd(DMA1_Channel1, ENABLE);
    DAC_DMACmd(DAC1, DAC_Channel_1, ENABLE);
}

static void DAC_setup(void){
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

    GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_4;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    DAC_InitStructure.DAC_Trigger = DAC_Trigger_T6_TRGO;
    DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
    DAC_InitStructure.DAC_Buffer_Switch = DAC_BufferSwitch_Disable;
    DAC_Init(DAC1, DAC_Channel_1, &DAC_InitStructure);
}

static void TIMER_setup(void){
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM6, ENABLE);

  TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
  TIM_TimeBaseStructure.TIM_Period = 100;
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
  TIM_TimeBaseInit(TIM6, &TIM_TimeBaseStructure);

  TIM_SelectOutputTrigger(TIM6, TIM_TRGOSource_Update);
  TIM_Cmd(TIM6, ENABLE);
}

int main(void){
    TIMER_setup();
    DAC_setup();
    DMA_setup();
    DAC_Cmd(DAC1, DAC_Channel_1, ENABLE);
}

Answer 1

您的程序只进行一些设置，仍然缺少“工作”部分 - 这将是一个计时器中断，并且在中断内部将 Sin12 数组中的单个值发送到 DAC，无论如何。首先开始不使用 DMA，确定后您可以通过更改为 DMA 支持来改进它。