Hello,
I've been doing a small project lately and ran into a problem in one part. I have two STM32 microcontrollers and I want to communicate both of them with eachother over UART. One of them is designed to send a fixed array of 6 characters
uint8_t k[6]={3,7,9,12,16,19};
The other microcontroller is simply to receive it. When I send a single byte over the UART it all works without a problem. When I want to send the whole array it only fills the first element.This first element is filled with random numbers from this sent array.
I know for sure there is no problem on the sending side. I checked it on an oscilloscope. The problem lies in the receiving side.
I suspect that the problem lies in the timing, but I don't know how to fix it
In both microcontrollers the baud rate is the same – 9600. The data frame is also the same 8N1.
RX device code
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t buff[6];
/* USER CODE END 0 */
/* USER CODE BEGIN WHILE */
while (1)
{
HAL_UART_Receive(&huart2, buff, sizeof(buff), 10000);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
TX device code
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t k[6]={3,7,9,12,16,19};
/* USER CODE END 0 */
/* USER CODE BEGIN WHILE */
while (1)
{
HAL_UART_Transmit(&huart2, k, sizeof(k), 10);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Try using interrupt method instead of polling.
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t buff[6];
volatile bool dataRdy = false;
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* 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_USART2_UART_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Receive_IT(&huart2, buff, sizeof(buff)); // initialize to receive
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
if(dataRdy)
{
dataRdy = 0;
if(buff[0] == 3) // check to see if first byte is 3
{
HAL_GPIO_TogglePin(LD2_GPIO_Port, LD2_Pin); // toggle led if data is valid
}
}
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/* USER CODE BEGIN 4 */
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if(huart == &huart2)
{
dataRdy = true;
HAL_UART_Receive_IT(&huart2, buff, sizeof(buff)); // re-initialize again
}
}
/* USER CODE END 4 */
Add a delay to your transmit
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t k[6]={3,7,9,12,16,19};
/* USER CODE END 0 */
/* USER CODE BEGIN WHILE */
while (1)
{
HAL_UART_Transmit(&huart2, k, sizeof(k), 10);
HAL_Delay(10);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
Make sure you have NVIC enabled
