Posted on April 04, 2015 at 08:49Hi,
I am a newbie in the field of micro-controllers and I'm having trouble programming the GPIOA parts as SPI1. Could someone please tell me where I could be going wrong? I would greatly appreciate if someone points me towards SPI implementation examples. The routines I've written so far are given below. I am trying to send just a byte of data and I am using a logic analyzer to check if there's a clock on SCK pin but I don't see anything happen. I also tried toggling an LED by sending data continuously but even this fails.
void spi_initialization(void)
{
SPI_I2S_DeInit(SPI1);
SPI_InitStructure.SPI_Direction= SPI_Direction_1Line_Tx;
SPI_InitStructure.SPI_Mode= SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize= SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL=SPI_CPHA_2Edge;
SPI_InitStructure.SPI_CPHA= SPI_CPOL_High;
SPI_InitStructure.SPI_NSS=SPI_NSS_Soft ;
SPI_InitStructure.SPI_BaudRatePrescaler=SPI_BaudRatePrescaler_2;
SPI_InitStructure.SPI_FirstBit=SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial=7;
SPI_Init(SPI1,&SPI_InitStructure);
SPI_RxFIFOThresholdConfig(SPI1, SPI_RxFIFOThreshold_QF);
/* Enable SPI1 CRC calculation */
SPI_CalculateCRC(SPI1, ENABLE);
//SPI_BiDirectionalLineConfig(SPI1, SPI_Direction_Tx);
SPI_Cmd(SPI1, ENABLE);
}
void send_byte(uint8_t val)
{
GPIO_ResetBits(GPIOA, GPIO_Pin_4); // CS low
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET); //wait buffer empty
SPI_SendData8(SPI1, val);
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_BSY) == SET); //wait finish sending
GPIO_SetBits(GPIOA, GPIO_Pin_4); // CS high
}
void RCC_config()
{
//System clock set as HSI
RCC_SYSCLKConfig(RCC_SYSCLKSource_HSI);
// clock freq is 4MHz
RCC_HCLKConfig(RCC_SYSCLK_Div2);
// CLock freq divided by 2 to get 2MHz again on APB2 peripherals for SPI1
//RCC_PCLK2Config(RCC_HCLK_Div1);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOE, ENABLE);
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
}
void GPIO_config()
{
// Setting the pins for alternate mode SPI configura MOSI, SS, SCK
//GPIO_PinAFConfig(GPIOA, GPIO_PinSource4|GPIO_PinSource5|GPIO_PinSource7, GPIO_AF_5);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
// Set GPIO pin for reset of LCD
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOE, &GPIO_InitStructure);
// Set GPIO pin as NO PULL for RS functionality
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStructure);
}
int main(void)
{
// Initialize clocks
RCC_config();
GPIO_config();
spi_initialization();
send_byte(0xFF);
}
#spi-protocol-stm32f303
