Code is compiling but not reading value from the sensor.
I have used the example code for my board downloaded from here, and it works. So sensor is okay
I don't have a oscilloscope, but i have captured the value of x and WHO_AM_I register using STMStudio
Here's main part of my code, not modified any other part of code
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
uint8_t x1, x2;
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_SPI5_Init();
/* USER CODE BEGIN 2 */
// ***** Spi Transmit ***** //
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x20;
spiTxBuf[1] = 0xFF;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 2, 50);
// 3. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x21;
spiTxBuf[1] = 0x00;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 2, 50);
// 3. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x24;
spiTxBuf[1] = 0x10;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 2, 50);
// 3. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x23;
spiTxBuf[1] = 0x20;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 2, 50);
// 3. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
// *** Code to read WHO_AM_I register *** //
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x0F | 0x80;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 1, 50);
// 3. Receive data
HAL_SPI_Receive(&hspi5, &who_am_i, 1, 50);
// 4. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x28 | 0x80;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 1, 50);
// 3. Receive data
HAL_SPI_Receive(&hspi5, &x1, 1, 50);
// 4. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
// 1. Bring slave select low
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET);
// 2. Transmit register + data
spiTxBuf[0] = 0x29 | 0x80;
HAL_SPI_Transmit(&hspi5, spiTxBuf, 1, 50);
// 3. Receive data
HAL_SPI_Receive(&hspi5, &x2, 1, 50);
// 4. Bring slave select high
HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET);
//x = ((int16_t)x1 | (x2 << 8));
x = (int16_t)x2;
x = x << 8;
x |= (int16_t)x1;
HAL_Delay(500);
}
}who_am_i is a uint8_t variable declared globally and the value I got from STM studio is 212(0xD4) comparing with data sheet it's the correct value. right??
But one thing I noticed is, value of x is changing after every reset.
Following are the screen shots of value of x after each reset (Board is not moved)
Screenshot after moving the board and resetting it
After reset even if I move the board, value is not changing
Are these the proper values given to the registers of L3GD20
addr value
0x20 ===> 0xFF
0x21 ===> 0x00
0x24 ===> 0x10
0x23 ===> 0x20
When generating code using cube MX, I have used HSI as clock source and all peripherals are running at 16 MHz. Would this cause any issue?
Please see this thread too, I have used his code too, but not working
Thanks
