SPI buffer zero reading : 1 line rx only in master mode

Posted on April 30, 2014 at 17:03

Hello all,

I am strugling with an spi communication between my ''stm32f3discovey '' and a resolver chip AS5311.

Took me some time but I managed to make the clock and the communication working has I can see on my scope. Only problem is despite good  transmission, when i read the buffer, it return only zeros.

Here is my program :

void init_spi_spi2(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

NVIC_InitTypeDef NVIC_InitStructure;

SPI_InitTypeDef SPI_InitStructure;

/* Enable SCK, MOSI, MISO and NSS GPIO clocks */

RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

/* Enable the SPI periph */

RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);

/* GPIO SPI port init structure */

/* SPI NSS pin configuration */

GPIO_PinAFConfig(GPIOB, GPIO_PinSource12, GPIO_AF_5);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;

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_UP;

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* SPI SCK pin configuration */

GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_5);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;

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_UP;

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* SPI MISO pin configuration */

GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_5);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;//GPIO_Mode_AF

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;//GPIO_OType_PP

GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_NOPULL;//GPIO_PuPd_UP

GPIO_Init(GPIOB, &GPIO_InitStructure);

/* SPI  MOSI pin configuration */

// GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_6);

// GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;

// 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_UP;

// GPIO_Init(GPIOB, &GPIO_InitStructure);

/* SPI configuration */

SPI_I2S_DeInit(SPI2);

SPI_InitStructure.SPI_Direction = SPI_Direction_1Line_Rx;

SPI_InitStructure.SPI_Mode = SPI_Mode_Master;

SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;

SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;

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 = 1;

SPI_Init(SPI2, &SPI_InitStructure);

SPI_RxFIFOThresholdConfig(SPI2, SPI_RxFIFOThreshold_QF);

SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_RXNE, ENABLE);

/* Configure the SPI interrupt priority */

NVIC_InitStructure.NVIC_IRQChannel = SPI2_IRQn;

NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;

NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;

NVIC_Init(&NVIC_InitStructure);

}

void begin_spi_transmission(void)

{

/* Enable SPI com for data retrieval */

dataCounter = 0;

SPI_NSSInternalSoftwareConfig(SPI2, SPI_NSSInternalSoft_Set);

SPI_SSOutputCmd(SPI2, ENABLE);

SPI_Cmd(SPI2, ENABLE);

}

void SPI2_IRQHandler(void)

{

static uint8_t temp = 0;

/* SPI in Master Receiver mode */

temp = SPI_ReceiveData8(SPI2);

//temp = SPI_I2S_ReceiveData16(SPI2);

//temp = SPI2->DR;

printf(''%u\n'', temp);

/* The disable control must occur just between the sampling time of the first */

/* bit of the last received frame and first bit of next (unwanted dummy) data frame. */

if (dataCounter == (spiMessage2->numberOfdata-1))

SPI_Cmd(SPI2, DISABLE);

/* there is no more data to receive */

if (dataCounter >= spiMessage2->numberOfdata) {

STM_EVAL_LEDOff(LED7);

/* we need to shut down the SPI com */

SPI_NSSInternalSoftwareConfig(SPI2, SPI_NSSInternalSoft_Reset);

SPI_SSOutputCmd(SPI2, DISABLE);

//SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_RXNE, DISABLE);

if (spiMessage2->spiSuccessCallback != NULL)

(*spiMessage2->spiSuccessCallback)();

del_voidCircularBuffer_bufferHead(spiBuffer);

}

}

Thanks for your time.

tags :

SPI_Direction_1Line_Rx

rxonly

interrupt

SPI_Mode_Master

zero

#spi-spi_direction_1line_rx