Hello,
I am using STM32H745 to setup and communicate with LIS2DW12 accelerometer via SPI 4-wires. I am trying to setup the accelerometer and I started with reading the WHO_AM_I register. It's default value is (43h) and I changed the value of the first bit to '1' so that my STM32 can read the value.
The SPI communication is setup as follows:
With the read and write fucntions set like this:
HAL_StatusTypeDef spi_write_LIS2DS12(uint8_t regAddr, uint8_t *pData)
{
HAL_StatusTypeDef ret;
uint8_t address = regAddr & 0x7F;
uint8_t sendData[2] = {address, *pData};
//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4, 0);
ret = HAL_SPI_Transmit(&hspi2, sendData, 2, 20);
//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4, 1);
return ret;
}
HAL_StatusTypeDef spi_read_LIS2DS12(uint8_t regAddr, uint8_t *pData)
{
HAL_StatusTypeDef ret = 0x01;
uint8_t address = regAddr | 0x80; // Set the Read/Write bit to 1 for read operation
uint8_t sendData[2]= {address,0};
uint8_t receiveData[2] = {0};
//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4, GPIO_PIN_RESET);
HAL_StatusTypeDef status = HAL_SPI_TransmitReceive(&hspi2, sendData, receiveData, 2, 50);
//HAL_GPIO_WritePin(GPIOB, GPIO_PIN_4, GPIO_PIN_SET);
*pData = receiveData[1];
return ret;
}
When I observe the MISO and MOSI with a logic analyzer, I can see that good register value is sent, but I have random 0s and 1s as a return of MISO. Here is a picture of how it looks:
I tried to add a reboot and/or soft reset before reading the WHO_AM_I registor, but it did not change much. Does anyone know what is the cause of this behaviour and how can it be fixed?
