STM32的SPI查詢(xún)方式傳輸測試

主機:WIN7

開(kāi)發(fā)環(huán)境:MDK4.23

MCU:STM32F103CBT6

說(shuō)明:

軟件設置NSS腳,利用查詢(xún)方式傳輸

源代碼:

初始化代碼:

//關(guān)閉SPISPI_Cmd(SPI1,DISABLE);//初始化SPI接口的SSN腳以及NTRX的RST腳NtrxCtrlInit();//初始化SPI時(shí)鐘	RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA,ENABLE);//配置SPI1引腳:SCK, MISO and MOSIGPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP ;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz ;GPIO_Init( GPIOA, &GPIO_InitStructure );// SPI1配置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波特率分頻設置:4MSPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8 ;//SPI設置成LSB模式SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_LSB ;SPI_InitStructure.SPI_CRCPolynomial = 7 ;SPI_Init( SPI1, &SPI_InitStructure ) ;//啟動(dòng)SPISPI_Cmd(SPI1,ENABLE);

發(fā)送代碼:

//SPI發(fā)送一個(gè)字節static uint8 SPI_SendByte(uint8 Data){// Loop while DR register in not empltywhile( SPI_I2S_GetFlagStatus( SPI1, SPI_I2S_FLAG_TXE ) == RESET ) ;// Send byte through the SPI1 peripheralSPI_I2S_SendData( SPI1, Data ) ;// Wait to receive a bytewhile( SPI_I2S_GetFlagStatus( SPI1, SPI_I2S_FLAG_RXNE ) == RESET ) ;// Return the byte read from the SPI busreturn SPI_I2S_ReceiveData( SPI1 ) ;}

接收代碼:

//SPI讀取一個(gè)字節void SPI_ReadBytes( uint8 Addr, NtrxBufferPtr Buffer, uint8 Len ){if( ( Len > 0x80 ) || ( Len == 0 ) )Len = 1 ;SPI_SendByte( Len ) ;SPI_SendByte( Addr ) ;while( Len-- ){*Buffer = SPI_SendByte( 0xFF ) ;Buffer ++ ;}}

NSS腳電平設置:

//SSN腳拉低,開(kāi)始發(fā)送數據void NtrxSSN_Lo( void ){GPIO_ResetBits( NTRX_SSN_PORT, NTRX_SSN_PIN ) ;}//SSN腳置高,結束發(fā)送數據void NtrxSSN_Hi( void ){GPIO_SetBits( NTRX_SSN_PORT, NTRX_SSN_PIN ) ;}

示例代碼:

uint8 NtrxReadSingleSPI( uint8 Addr ){NtrxBufferType r ;NtrxSSN_Lo() ;SPI_ReadBytes( Addr, &r, 1 ) ;NtrxSSN_Hi() ;return r ;}

輸出:

黃線(xiàn)為NSS腳電平,藍線(xiàn)為CLK電平.