Posted on December 09, 2012 at 14:41Hello,
I'm trying to get the MEMS Accelerometer on my STM32F4 Discovery Board to run with a simple code, but I don't make it.
Heres my code:
int main(void)
{
SystemInit();
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOE , ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
//Init SPI-Pins
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
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_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Init CS-Pin
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_SetBits(GPIOE, GPIO_Pin_3); //Set CS high
GPIO_PinAFConfig (GPIOA, GPIO_PinSource5 |GPIO_PinSource6 |GPIO_PinSource7 , GPIO_AF_SPI1);
SPI_I2S_DeInit(SPI1);
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master ;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b ;
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_32;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 0;
SPI_Init(SPI1, &SPI_InitStructure);
SPI_Cmd(SPI1, ENABLE);
GPIO_ResetBits(GPIOE, GPIO_Pin_3);
SPI_I2S_SendData(SPI1, 0x20C7); //Sensor Config
while(1){
//Read Y-Axis
SPI_I2S_SendData(SPI1, 0xAB00);
SPI_I2S_ReceiveData(SPI1);
}
I'm running this in Debug-mode only (step by step), so there should not be any timing problems due to missing flag-status requests.
After sending the data, RXNE bit in SPI SR Register is set but the SPI Data Register always contains 0x0000. I have also tried different modes changing CPOL and CPHA, no results.
I am using CooCox IDE
I hope somebody can help!
Thanks,
Alex.
#accelerometer #stm32f4 #spi #metoo
