stm32 硬件spi例程

以下是基于STM32的硬件SPI的例程：

#include "stm32f4xx.h"

void SPI_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    SPI_InitTypeDef SPI_InitStruct;

    // Step 1: Initialize GPIO
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;    GPIO_Init(GPIOA, &GPIO_InitStruct);

    // Step 2: Initialize SPI
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);

    SPI_InitStruct.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
    SPI_InitStruct.SPI_Mode = SPI_Mode_Master;
    SPI_InitStruct.SPI_DataSize = SPI_DataSize_8b;
    SPI_InitStruct.SPI_CPOL = SPI_CPOL_Low;
    SPI_InitStruct.SPI_CPHA = SPI_CPHA_1Edge;
    SPI_InitStruct.SPI_NSS = SPI_NSS_Soft;
    SPI_InitStruct.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
    SPI_InitStruct.SPI_FirstBit = SPI_FirstBit_MSB;
    SPI_InitStruct.SPI_CRCPolynomial = 7;
    SPI_Init(SPI1, &SPI_InitStruct);

    // Step 3: Enable SPI
    SPI_Cmd(SPI1, ENABLE);
}

uint8_t SPI_SendByte(uint8_t byte)
{
    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
    SPI_I2S_SendData(SPI1, byte);
    while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
    return SPI_I2S_ReceiveData(SPI1);
}

int main(void)
{
    SPI_Init();

    while (1)
    {
        // Send and receive data
        uint8_t tx_data = 0x55;
        uint8_t rx_data = SPI_SendByte(tx_data);
    }
}