SPI2 won't work

[pinto-gaetan]

Posted on May 03, 2012 at 12:08

Hi,

I've been trying to solve this problem for quite a while now. I 've get throuth various forum or example projet but nothing do the trick . My stm32f107 is connected by spi with another microchip (blackfin 537). I've extract my configuration code from various sample ST project :

void
RCC_Configuration(
void
) 
{ 
/* PCLK2 = HCLK/2 */
RCC_PCLK2Config(RCC_HCLK_Div2); 
/* Enable peripheral clocks --------------------------------------------------*/
/* GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); 
/* SPI2 TIM4 Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2 | RCC_APB1Periph_TIM4, ENABLE); 
// I use tim4 for delay purpose and it works fine 
} 
void
SPI_Configuration(SPI_InitTypeDef * SPI_InitStructure) 
{ 
/* SPI2 Config -------------------------------------------------------------*/
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_High; 
SPI_InitStructure->SPI_CPHA = SPI_CPHA_2Edge; 
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; 
} 
void
SPI_Initialisation(SPI_InitTypeDef SPI_InitStructure){ 
SPI_I2S_DeInit(SPI2); 
/* Set SPI2 SS high*/
GPIO_SetBits(GPIOB, GPIO_Pin_12); 
/* Init SPI2 */
SPI_Init(SPI2, &SPI_InitStructure); 
/* Enable SPI2 */
SPI_Cmd(SPI2, ENABLE); 
} 
void
GPIO_Configuration(
void
) 
{ 
GPIO_InitTypeDef GPIO_InitStructure; 
/* Configure SPI2 pins: custom SS ----------------------------*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12; 
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 
GPIO_Init(GPIOB, &GPIO_InitStructure); 
//CLK,MOSI 
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_15; 
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; 
GPIO_Init(GPIOB, &GPIO_InitStructure); 
//MISO 
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_14; 
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; 
GPIO_Init(GPIOB, &GPIO_InitStructure); 
} 
void
NVIC_Configuration(
void
) 
{ 
NVIC_InitTypeDef NVIC_InitStructure; 
#ifdef VECT_TAB_RAM 
/* Set the Vector Table base location at 0x20000000 */
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); 
#else /* VECT_TAB_FLASH */ 
/* Set the Vector Table base location at 0x08000000 */
NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); 
#endif 
/* Configure and enable SPI2 interrupt -------------------------------------*/
NVIC_InitStructure.NVIC_IRQChannel = SPI2_IRQChannel; 
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; 
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 
NVIC_Init(&NVIC_InitStructure); 
}

Here's the spi configuration that i need: -master -8bit -CPOL = 1 -CPHA = 1 -nss was a big problem (as it doesn't act as a true chip select) but i managed to manualy make it high or low) -high prescaler possible for debugging -little endian -CRC not needed here's my transmission function :

u8 SPI_Manager_Transmit(u8* ToSend ,u8* ToReceive , u16 length, SPI_Manager * me){ 
u8 ret = 0; 
/*[there is some code here related to my app]*/
// Enable SPI2 Transmit interrupts 
SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_TXE, ENABLE); 
// Enable SPI2 Receive interrupts 
SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_RXNE, ENABLE); 
//loop until reception and send are complet 
while
(*(me->toTransfert) > *(me->transfered) || *(me->toReceive) > *(me->received)) 
{ 
//blocking loop 
} 
return
ret; 
}

I use interupt to send and receive so here's the SPI2 interupt handler :

void
SPI2_IRQHandler(
void
) 
{ 
if
(SPI_I2S_GetITStatus(SPI2, SPI_I2S_IT_RXNE) == SET) 
{ 
/* Read one byte from the receive data register */
RxBuffer[RxCounter++] = SPI_I2S_ReceiveData(SPI2); 
if
(RxCounter == NbrOfDataToRead) 
{ 
/* Disable the SPI2 Receive interrupt */
SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_RXNE, DISABLE); 
} 
} 
if
(SPI_I2S_GetITStatus(SPI2, SPI_I2S_IT_TXE) == SET) 
{ 
/* Write one byte to the transmit data register */
SPI_I2S_SendData(SPI2, TxBuffer[TxCounter++]); 
if
(TxCounter == NbrOfDataToTransfer) 
{ 
/* Disable the SPI2 Transmit interrupt */
SPI_I2S_ITConfig(SPI2, SPI_I2S_IT_TXE, DISABLE); 
} 
} 
}

I think i didn't forget anything related to SPI2. Currently the chip select and the clock are ok. I can see them on an ocilloscope. But there is no sign of MOSI. MISO is constantly at +3V,don't know where that come from, maybe the other microchip ? I think I've could have misconfigured GPIOs or maybe killed some (they may have been damaged by a > 5V current) Any help would be welcomed, I'm new to all this so I could have done common mistakes.

[pinto-gaetan]

Posted on May 03, 2012 at 16:05

Looks like my chip select don't work that ok after all. I rechecked it ...

when i call

GPIO_SetBits(GPIOB, GPIO_Pin_12);

It's only go up to 1V. It's a 3V output, isn't it ?

[Tesla DeLorean]

Posted on May 03, 2012 at 19:20

It's only go up to 1V. It's a 3V output, isn't it ?

Sounds like it's fighting some other output.

[pinto-gaetan]

Posted on May 04, 2012 at 09:20

There's a +0.14V on the other microchip CS pin when nothing is connected. That could prevent the chip select to pass ?

The pin I use as CS is the SPI2 NSS. Since I use this periph without enabling NSS output, could it conflict his standard operation ?

[pinto-gaetan]

Posted on May 04, 2012 at 10:04

Some good news this morning, I was able to read from the slave ! As the CS pin is still low, even at +1V, for the other chip, the signal passed.

But there's still nothing passing through MOSI.

[pinto-gaetan]

Posted on May 04, 2012 at 15:09

After further testing, I discovered that my SPI2 can't send data but SPI is able

here's a small table showing the testing result

  SPI1   SPI2

receive data   not able  able

send data  able  not able

send clock  not able  able

I can't see any reason of such result ...

Anyway, I managed to make both SPI work together to get Tx and Rx capabilities.

This is kind of dirty but it looks working for now.