编写一个SPI2通过DMA传输ADS1256数据程序

以下是一个简单的示例程序，用于使用STM32的SPI2和DMA传输ADS1256数据：

#include "stm32f4xx.h"
#include "stm32f4xx_spi.h"
#include "stm32f4xx_dma.h"

#define ADS1256_SPI SPI2
#define ADS1256_DMA DMA1
#define ADS1256_DMA_STREAM DMA1_Stream3

uint8_t ADS1256_SPI_Transmit(uint8_t data)
{
    while (SPI_I2S_GetFlagStatus(ADS1256_SPI, SPI_I2S_FLAG_TXE) == RESET);
    SPI_I2S_SendData(ADS1256_SPI, data);
    while (SPI_I2S_GetFlagStatus(ADS1256_SPI, SPI_I2S_FLAG_RXNE) == RESET);
    return SPI_I2S_ReceiveData(ADS1256_SPI);
}

void ADS1256_DMA_Transfer(uint32_t* buffer, uint32_t size)
{
    DMA_InitTypeDef DMA_InitStructure;
    DMA_InitStructure.DMA_Channel = DMA_Channel_0;
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&(ADS1256_SPI->DR);
    DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)buffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;
    DMA_InitStructure.DMA_BufferSize = size;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;
    DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
    DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
    DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
    DMA_Init(ADS1256_DMA_STREAM, &DMA_InitStructure);
    DMA_Cmd(ADS1256_DMA_STREAM, ENABLE);
    while (DMA_GetFlagStatus(ADS1256_DMA_STREAM, DMA_FLAG_TCIF3) == RESET);
    DMA_ClearFlag(ADS1256_DMA_STREAM, DMA_FLAG_TCIF3);
}

void ADS1256_Init(void)
{
    // 初始化SPI2
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
    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_CPOL = SPI_CPOL_Low;
    SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
    SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
    SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_InitStructure.SPI_CRCPolynomial = 7;
    SPI_Init(ADS1256_SPI, &SPI_InitStructure);
    SPI_Cmd(ADS1256_SPI, ENABLE);

    // 初始化DMA1_Stream3
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE);
    DMA_DeInit(ADS1256_DMA_STREAM);
}

int main(void)
{
    uint32_t data[10]; // 假设要传输10个32位的数据
    ADS1256_Init();
    ADS1256_DMA_Transfer((uint32_t*)data, sizeof(data));
    while (1);
}

注：此示例代码仅用于参考，实际实现可能需要进一步修改。