Question

我在STM32F4 Discovery上有STM32F4407VGT6控制器。我尝试使用SPI + DMA从AD7683 ADC读取数据，但DMA接收缓冲区始终为空（全为零）。在轮询模式下，一切正常，但我必须读取一个16位采样值作为3x 8位SPI值并使用位移位。这可能就是问题所在。我的采样频率为48 kHz，并且在每个周期内必须读取三个spi值以获得一个ADC样本。

AD7683时序图位于datasheet，第5页。

引脚上的SPI通信很好。以下是分析器的屏幕：pic

有谁知道如何解决这个问题，或问题出在哪里？

提前致谢。

这是我的代码：

#define DMAbufferSizeRx 3
__IO uint8_t DMAbufferRx[DMAbufferSizeRx];

#define DMAbufferSizeTx 1
__IO uint8_t DMAbufferTx[DMAbufferSizeTx] ;

void DMAconfig(void)
{

NVIC_InitTypeDef NVIC_InitStructure;

/* Enable the DMA Stream IRQ Channel */
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);





DMA_InitTypeDef DMA_InitStructure;

DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable ;
DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_1QuarterFull ;
DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single ;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;

DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)(&(SPI3->DR));
DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;




// Configure Tx DMA
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t) &DMAbufferTx[0];
DMA_InitStructure.DMA_BufferSize = DMAbufferSizeTx;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Disable;
DMA_Cmd(DMA1_Stream5, DISABLE);
while (DMA1_Stream5->CR & DMA_SxCR_EN);
DMA_Init(DMA1_Stream5, &DMA_InitStructure);


/* Configure Rx DMA */
DMA_InitStructure.DMA_Channel = DMA_Channel_0;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t) &DMAbufferRx[0];
DMA_InitStructure.DMA_BufferSize = DMAbufferSizeRx;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_Cmd(DMA1_Stream0, DISABLE);
while (DMA1_Stream0->CR & DMA_SxCR_EN);
DMA_Init(DMA1_Stream0, &DMA_InitStructure);



DMA_ITConfig(DMA1_Stream0, DMA_IT_TC , ENABLE); //| DMA_IT_HT

/* Enable the DMA channel */

DMA_ClearFlag(DMA1_Stream0, DMA_FLAG_FEIF0|DMA_FLAG_DMEIF0|DMA_FLAG_TEIF0|DMA_FLAG_HTIF0|DMA_FLAG_TCIF0);
DMA_ClearFlag(DMA1_Stream5, DMA_FLAG_FEIF5|DMA_FLAG_DMEIF5|DMA_FLAG_TEIF5|DMA_FLAG_HTIF5|DMA_FLAG_TCIF5);


DMA_Cmd(DMA1_Stream0, ENABLE); // Enable the DMA SPI TX Stream
DMA_Cmd(DMA1_Stream5, ENABLE); // Enable the DMA SPI RX Stream


// Enable the SPI Rx/Tx DMA request
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Rx, ENABLE);
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);

SPI_Cmd(SPI3, ENABLE);

}






void DMA1_Stream0_IRQHandler(void)  
{
  /* Test on DMA Stream Transfer Complete interrupt */
  if(DMA_GetITStatus(DMA1_Stream0, DMA_IT_TCIF0))
  {
    /* Clear DMA Stream Transfer Complete interrupt pending bit */
    DMA_ClearITPendingBit(DMA1_Stream0, DMA_IT_TCIF0);

      // here is buffer still empty....
  }
}






void SPIconfig()
{

SPI_InitTypeDef SPI_InitStructure;

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode    = SPI_Mode_Master;            
SPI_InitStructure.SPI_DataSize   = SPI_DataSize_8b;       
SPI_InitStructure.SPI_DataSize   = SPI_FirstBit_MSB;      
SPI_InitStructure.SPI_CPOL     = SPI_CPOL_High;            
SPI_InitStructure.SPI_CPHA     = SPI_CPHA_2Edge;     
SPI_InitStructure.SPI_NSS     = SPI_NSS_Soft | SPI_NSSInternalSoft_Set; 

SPI_InitStructure.SPI_BaudRatePrescaler  =SPI_BaudRatePrescaler_16; 
SPI_InitStructure.SPI_CRCPolynomial   = 0; 

SPI_Init(SPI3, &SPI_InitStructure);                         
SPI_CalculateCRC(SPI3, DISABLE);                         
SPI_Cmd(SPI3,ENABLE);                       
}   




void RCCenable(void)
{
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); 
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE); 
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE); 
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE); 
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOH, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3,  ENABLE);  
RCC_AHB1PeriphClockCmd( RCC_AHB1Periph_DMA1, ENABLE);
}






void GPIOconfig(void)
{

GPIO_InitTypeDef GPIO_InitDef;

GPIO_InitDef.GPIO_Pin =  REG_ON_OFF | ADC_DRIVER_ON_OFF | GPIO_Pin_6;
GPIO_InitDef.GPIO_OType = GPIO_OType_PP;
GPIO_InitDef.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitDef.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitDef.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_Init(GPIOE, &GPIO_InitDef);



GPIO_InitTypeDef GPIO_InitStructure;

GPIO_InitStructure.GPIO_Pin   = SDATA | MOSI | SCLK;
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF; 
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOB, GPIO_PinSource3, GPIO_AF_SPI3);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource4, GPIO_AF_SPI3); 
GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_SPI3);



GPIO_InitStructure.GPIO_Pin   = CS;
GPIO_InitStructure.GPIO_Mode   = GPIO_Mode_OUT; 
GPIO_InitStructure.GPIO_PuPd   = GPIO_PuPd_UP;   
GPIO_Init(GPIOD, &GPIO_InitStructure);

GPIO_SetBits(GPIOD,CS); 
}




void TIM2_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);

        GPIO_ToggleBits(GPIOD,CS);

    }
}



void TIM2_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;

NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);


TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

TIM_TimeBaseStructure.TIM_Period = 875; 
TIM_TimeBaseStructure.TIM_Prescaler = 0; 
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);

TIM_Cmd(TIM2, ENABLE);
}

Answer 1

您可能会两次初始化DMA_Mode，DMA_MemoryDataSize和DMA_MemoryInc字段。它没用 - 只保存了最后一句话。

此时DMA_PeripheralDataSize与DMA_MemoryDataSize不匹配。

你没有附加main函数，所以我看不到init函数的调用顺序。必须在DMAconfig()之前调用SPIconfig()。

SPIconfig处有下一个错误：

1）我想你猜，你有什么要纠正的。

SPI_InitStructure.SPI_DataSize = SPI_FirstBit_MSB;

2）改变

SPI_InitStructure.SPI_NSS     = SPI_NSS_Soft |
SPI_NSSInternalSoft_Set;

到

SPI_init.SPI_NSS = SPI_NSS_Soft;

最终像这样初始化：

SPI_Init(SPI3, &SPI_init);
SPI_SSOutputCmd(SPI3, ENABLE); //!!!!
SPI_Cmd(SPI3, ENABLE);
SPI_NSSInternalSoftwareConfig(SPI3, SPI_NSSInternalSoft_Set); //!!!!
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);

希望如果你还没有解决问题，它会有所帮助。

Answer 2

我们将AD7685与STM32F427ZGT一起使用（仅在没有DMA的软件模式下）。但是我们也有问题与芯片通信。用这些参数解决了问题：

hspix.Init.Direction = SPI_DIRECTION_2LINES;
hspix.Init.DataSize = SPI_DATASIZE_16BIT;
GPIO_InitStruct.Pull = GPIO_PULLUP;

当然，HAL_SPI_Receive的大小现在只有1。

希望在某种程度上有所帮助。

此致

STM32f4 SPI DMA接收

2 个答案: