STM32 SPI SLAVE

﹏ヽ暗。殇╰゛Y 2022-08-01 12:27 200阅读 0赞

一般使用SPI都用MASTER,但是用SLAVE没有用过.参考了ST的例子,发现不能满足自己的使用.于是,自己修改了一下.

初始化配置SPI

/**
      ******************************************************************************
      * @file    app.c
      * @author  MCD Application Team
      * @version V1.1.0
      * @date    19-March-2012
      * @brief   This file provides all the Application firmware functions.
      ******************************************************************************
      * @attention
      *
      * <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
      *
      * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
      * You may not use this file except in compliance with the License.
      * You may obtain a copy of the License at:
      *
      *        http://www.st.com/software_license_agreement_liberty_v2
      *
      * Unless required by applicable law or agreed to in writing, software 
      * distributed under the License is distributed on an "AS IS" BASIS, 
      * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      * See the License for the specific language governing permissions and
      * limitations under the License.
      *
      ******************************************************************************
      */ 
    
    /* Includes ------------------------------------------------------------------*/ 
    
    #include "usbd_cdc_core.h"
    #include "usbd_usr.h"
    #include "usb_conf.h"
    #include "usbd_desc.h"
    #define	RECV_SIZE			(1024 * 16)
    u8 g_cbRecvBuffer[RECV_SIZE] = {0};
    
     SPI_InitTypeDef  SPI_InitStructure;
    RECV_STRUCT g_sRecvInfo = {0};
    
    
    /**
      * @brief  Configures the SPI Peripheral.
      * @param  None
      * @retval None
      */
    static void SPI_Config(void)
    {
      GPIO_InitTypeDef GPIO_InitStructure;
      NVIC_InitTypeDef NVIC_InitStructure;
    
      /* Peripheral Clock Enable -------------------------------------------------*/
      /* Enable the SPI clock */
      SPIx_CLK_INIT(SPIx_CLK, ENABLE);
      
      /* Enable GPIO clocks */
      RCC_AHB1PeriphClockCmd(SPIx_SCK_GPIO_CLK | SPIx_MISO_GPIO_CLK | SPIx_MOSI_GPIO_CLK, ENABLE);
    
      /* SPI GPIO Configuration --------------------------------------------------*/
      /* GPIO Deinitialisation */
      GPIO_DeInit(SPIx_SCK_GPIO_PORT);
      GPIO_DeInit(SPIx_MISO_GPIO_PORT);
      GPIO_DeInit(SPIx_MOSI_GPIO_PORT);
      
      /* Connect SPI pins to AF5 */  
      GPIO_PinAFConfig(SPIx_SCK_GPIO_PORT, SPIx_SCK_SOURCE, SPIx_SCK_AF);
      GPIO_PinAFConfig(SPIx_MISO_GPIO_PORT, SPIx_MISO_SOURCE, SPIx_MISO_AF);    
      GPIO_PinAFConfig(SPIx_MOSI_GPIO_PORT, SPIx_MOSI_SOURCE, SPIx_MOSI_AF);
      GPIO_PinAFConfig(SPIx_NSS_GPIO_PORT, SPIx_NSS_SOURCE, SPIx_NSS_AF);
    
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
    
      /* SPI SCK pin configuration */
      GPIO_InitStructure.GPIO_Pin = SPIx_SCK_PIN;
      GPIO_Init(SPIx_SCK_GPIO_PORT, &GPIO_InitStructure);
      
      /* SPI  MISO pin configuration */
      GPIO_InitStructure.GPIO_Pin =  SPIx_MISO_PIN;
      GPIO_Init(SPIx_MISO_GPIO_PORT, &GPIO_InitStructure);  
    
      /* SPI  MOSI pin configuration */
      GPIO_InitStructure.GPIO_Pin =  SPIx_MOSI_PIN;
      GPIO_Init(SPIx_MOSI_GPIO_PORT, &GPIO_InitStructure);
      
       /* SPI  NSS pin configuration */
      GPIO_InitStructure.GPIO_Pin =  SPIx_NSS_PIN;
      GPIO_Init(SPIx_NSS_GPIO_PORT, &GPIO_InitStructure);
     
      /* SPI configuration -------------------------------------------------------*/
      SPI_I2S_DeInit(SPIx);
      SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
      SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
      SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
      SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
      SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;
      SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
      SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
      SPI_InitStructure.SPI_CRCPolynomial = 0;
      
      /* Configure the Priority Group to 1 bit */                
      NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
      
      /* Configure the SPI interrupt priority */
      NVIC_InitStructure.NVIC_IRQChannel = SPIx_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);
    }
    
    /**
      * @brief  Program entry point
      * @param  None
      * @retval None
      */
    int main(void)
    {
     g_sRecvInfo.lpBuffer = g_cbRecvBuffer;
     g_sRecvInfo.uWritePos = 0;
     g_sRecvInfo.uReadPos = 0;
     g_sRecvInfo.uSize = RECV_SIZE;
    
    
    
      /* SPI configuration */
      SPI_Config();
      
       SPI_InitStructure.SPI_Mode = SPI_Mode_Slave;
      SPI_Init(SPIx, &SPI_InitStructure);
     
      
      /* Enable the Rx buffer not empty interrupt */
      SPI_I2S_ITConfig(SPIx, SPI_I2S_IT_RXNE, ENABLE);
      
      /* Enable the Tx empty interrupt */
      SPI_I2S_ITConfig(SPIx, SPI_I2S_IT_TXE, ENABLE);
      
      /* Enable the SPI peripheral */
      SPI_Cmd(SPIx, ENABLE);
     
     
    
    
      /* Main loop */
      while (1)
      {
    
      }
    } 
    
    #ifdef USE_FULL_ASSERT
    /**
    * @brief  assert_failed
    *         Reports the name of the source file and the source line number
    *         where the assert_param error has occurred.
    * @param  File: pointer to the source file name
    * @param  Line: assert_param error line source number
    * @retval None
    */
    void assert_failed(uint8_t* file, uint32_t line)
    {
      /* User can add his own implementation to report the file name and line number,
      ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
      
      /* Infinite loop */
      while (1)
      {}
    }
    #endif
    
    /**
      * @}
      */ 
    
    
    /**
      * @}
      */ 
    
    
    /**
      * @}
      */ 
    
    /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

中断处理

/**
      * @brief  This function handles SPI interrupt request.
      * @param  None
      * @retval None
      */
    void SPIx_IRQHANDLER(void)
    {
      /* SPI in Receiver mode */
      if (SPI_I2S_GetITStatus(SPIx, SPI_I2S_IT_RXNE) == SET)
      {
       	  SPI_I2S_ReceiveData(SPIx);
      }
      /* SPI in Transmitter mode */
      if (SPI_I2S_GetITStatus(SPIx, SPI_I2S_IT_TXE) == SET)
      {
    	    if(g_sRecvInfo.uReadPos != g_sRecvInfo.uWritePos || g_sRecvInfo.bIsWriteNewCycle)
    	    {
    	        SPI_I2S_SendData(SPIx, *(g_sRecvInfo.lpBuffer + g_sRecvInfo.uReadPos));
    	        if(++g_sRecvInfo.uReadPos == g_sRecvInfo.uSize)
    	        {
    	          g_sRecvInfo.uReadPos = 0;
    		   g_sRecvInfo.bIsWriteNewCycle = 0;
    	        }
    	    }
    	    else
    	    {
    	        /* Send Transaction data */
    	        SPI_I2S_SendData(SPIx, 0xFF);
    	}
      }
    }

结构定义及对应IO定义

#include <string.h>
    #include "stm32f4xx_spi.h"
    typedef struct _Recv_cb
    {
    	u8 *lpBuffer;
    	u32 uWritePos;
    	u32 uReadPos;
    	u32	uSize;
    	u8	bIsWriteNewCycle;
    }RECV_STRUCT;
    
    
    
    #define BUFFERSIZE                       100
    
    #define SPIx                           SPI2
    #define SPIx_CLK                       RCC_APB1Periph_SPI2
    #define SPIx_CLK_INIT                  RCC_APB1PeriphClockCmd
    #define SPIx_IRQn                      SPI2_IRQn
    #define SPIx_IRQHANDLER                SPI2_IRQHandler
    
    #define SPIx_NSS_PIN                  GPIO_Pin_12
    #define SPIx_NSS_GPIO_PORT            GPIOB
    #define SPIx_NSS_GPIO_CLK             RCC_AHB1Periph_GPIOB
    #define SPIx_NSS_SOURCE               GPIO_PinSource12
    #define SPIx_NSS_AF                   GPIO_AF_SPI2
    
    #define SPIx_SCK_PIN                   GPIO_Pin_13
    #define SPIx_SCK_GPIO_PORT             GPIOB
    #define SPIx_SCK_GPIO_CLK              RCC_AHB1Periph_GPIOB
    #define SPIx_SCK_SOURCE                GPIO_PinSource13
    #define SPIx_SCK_AF                    GPIO_AF_SPI2
    
    #define SPIx_MISO_PIN                  GPIO_Pin_14
    #define SPIx_MISO_GPIO_PORT            GPIOB
    #define SPIx_MISO_GPIO_CLK             RCC_AHB1Periph_GPIOB
    #define SPIx_MISO_SOURCE               GPIO_PinSource14
    #define SPIx_MISO_AF                   GPIO_AF_SPI2
    
    #define SPIx_MOSI_PIN                  GPIO_Pin_15
    #define SPIx_MOSI_GPIO_PORT            GPIOB
    #define SPIx_MOSI_GPIO_CLK             RCC_AHB1Periph_GPIOB
    #define SPIx_MOSI_SOURCE               GPIO_PinSource15
    #define SPIx_MOSI_AF                   GPIO_AF_SPI2

注意:另外MASTER设备需要,先发送一个字节的时钟，然后再读取N个字节的时钟.

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