Is the STM32 library function HAL_UART_Receive blocking?

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Is the STM32 library function HAL_UART_Receive blocking? [Copy link]

Today I am testing STM32H743, mainly testing the reception of UART3 serial port, referring to ST company's routine material "UART communication on STM32 Microcontrollers using HAL"

1. /* USER CODE END Header_StartTask04 */ void StartTask04(void const * argument) { /* USER CODE BEGIN StartTask04 */ /* Infinite loop */ for(;;) { HAL_GPIO_TogglePin(LED3_GPIO_Port,LED3_Pin); char in[8]; HAL_UART_Receive(&huart3, (uint8_t *)in, 8, 0); HAL_UART_Transmit(&huart3, (uint8_t *)in, 8, 1); } /* USER CODE END StartTask04 */ }

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I found that this function is being executed continuously. It is said on the Internet that the HAL_UART_Receive function is blocked. Why does it keep executing?

RCSN

1. The HAL library communication transceiver has two interfaces. For example, the receiving interface is HAL_XXXX_Receive, which is a polling blocking interface. The parameter input Timeout is the polling blocking time. The other is HAL_XXXX_Receive_IT or _DMA, which is not an interrupt interface and needs to be completed with handle. 2. The HAL_UART_Receive(&huart3, (uint8_t *)in, 8, 0); posted by the original poster has Timeout of 0, which means that each tick only checks once whether the receiving completion flag is set.