Posted on September 10, 2016 at 20:32Hi everybody,
I'm writing this post to ask if someone, please, can help me resolving a problem with the datas-reading from the accelerometer integrated in the STM32F4 Evaluation Board.
What I want to do it's simply to read the accelerations datas from the sensor, using the SPI interface. I've had a look at a lot of examples but I still don't know why my code doesn't work.
Here the main functions:
void WriteAccelerometer(SPI_HandleTypeDef SPI, uint8_t address, uint8_t data)
{
HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_RESET); //CS --> Low
HAL_SPI_Transmit(&SPI,&address,1,50);
HAL_SPI_Transmit(&SPI,&data,1,50);
HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_SET); //CS --> High
}
uint8_t ReadAccelerometer(SPI_HandleTypeDef SPI, uint8_t address, uint8_t data)
{
address = address | 0x80;
HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_RESET); //CS --> Low
HAL_SPI_Transmit(&SPI,&address,1,50);
HAL_SPI_Receive(&SPI,&data,1,50);
HAL_GPIO_WritePin(GPIOE, GPIO_PIN_3, GPIO_PIN_SET); //CS --> High
return data;
}
Here the SPI configuration function:
static void MX_SPI1_Init(void)
{
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 10;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
//WriteAccelerometer(hspi1,0x23,0xC9); //reset
//WriteAccelerometer(hspi1,0x21,0x00);
}
I use the two functions reported in this post to configurate and read the accelerometer with this commands:
uint8_t config_address = 0x20;
uint8_t config_data = 0x27;
uint8_t Address_ACCX = 0x29;
uint8_t Address_ACCY = 0x2B;
uint8_t Address_ACCZ = 0x2D;
WriteAccelerometer(hspi1,config_address,config_data); //config
// read data:
AccX = ReadAccelerometer(hspi1,Address_ACCX,AccX);
AccY = ReadAccelerometer(hspi1,Address_ACCY,AccY);
AccZ = ReadAccelerometer(hspi1,Address_ACCZ,AccZ);
Thank you in advance for the help..
Simone
