Description
As the title says, today I am going to show you how to use UART for serial communication in STM32 devices. I am going to use STM32CubeMx to generate necessary code and than edit the code in Keil uvision 5.
UART is widely used for serial communication between two devices. It is easy to use protocol, because the clock sync is not involved. All you have to do is take care of BAUD RATE. BAUD RATE must be same for both devices, amongst which communication is done. I am going to use 9600 as it is standard.
I have already explained the detailed working of UART in my LPC2148 tutorial. If you want the full explanation of working of UART, please visit here. This basic working remains same throughout no matter which microcontroller you are using right now so I am going to skip that part and just show you guys how to set up UART in STM32.
Procedure:-
1.) Open the cubemx and select your board. Select the UART you want to use for communication. I am using UART2.
2.) In the ‘configuration’ tab, make sure USART settings are as follows.
3.) That’s it for cubemx. Now generate the project and open in the respective IDE. I am using keil uvision.
Some Insight into the Code:-
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uint8_t data[] = "HELLO WORLD!n"; while (1) { HAL_UART_Transmit (&huart2, data, 14, 50); HAL_Delay (1000); } HAL_UART_Transmit function takes following arguments- UART_HandleTypeDef *huart, --> This is uart handle as I am using UART2 so the handle is huart2 uint8_t *pData, --> the data to be sent uint16_t Size, --> size of data uint32_t Timeout --> timeout before error in milliseconds |
CODE
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/* Includes ------------------------------------------------------------------*/ #include "main.h" #include "stm32f4xx_hal.h" /* USER CODE BEGIN Includes */ /* USER CODE END Includes */ /* Private variables ---------------------------------------------------------*/ UART_HandleTypeDef huart2; /* USER CODE BEGIN PV */ /* Private variables ---------------------------------------------------------*/ /* USER CODE END PV */ /* Private function prototypes -----------------------------------------------*/ void SystemClock_Config(void); void Error_Handler(void); static void MX_GPIO_Init(void); static void MX_USART2_UART_Init(void); /* USER CODE BEGIN PFP */ /* Private function prototypes -----------------------------------------------*/ uint8_t data[] = "HELLO WORLD!n"; /* USER CODE END PFP */ /* USER CODE BEGIN 0 */ /* USER CODE END 0 */ 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(); /* Configure the system clock */ SystemClock_Config(); /* Initialize all configured peripherals */ MX_GPIO_Init(); MX_USART2_UART_Init(); /* USER CODE BEGIN 2 */ /* USER CODE END 2 */ /* Infinite loop */ /* USER CODE BEGIN WHILE */ while (1) { /* USER CODE END WHILE */ /* USER CODE BEGIN 3 */ HAL_UART_Transmit (&huart2, data, 14, 50); HAL_Delay (1000); // wait for 1 sec } /* USER CODE END 3 */ } /* USART2 init function */ static void MX_USART2_UART_Init(void) { huart2.Instance = USART2; huart2.Init.BaudRate = 9600; huart2.Init.WordLength = UART_WORDLENGTH_8B; huart2.Init.StopBits = UART_STOPBITS_1; huart2.Init.Parity = UART_PARITY_NONE; huart2.Init.Mode = UART_MODE_TX_RX; huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE; huart2.Init.OverSampling = UART_OVERSAMPLING_16; if (HAL_UART_Init(&huart2) != HAL_OK) { Error_Handler(); } } /** Configure pins as * Analog * Input * Output * EVENT_OUT * EXTI */ static void MX_GPIO_Init(void) { /* GPIO Ports Clock Enable */ __HAL_RCC_GPIOH_CLK_ENABLE(); __HAL_RCC_GPIOA_CLK_ENABLE(); } |
Result
“hello World!” is transmitted from microcontroller to the computer and is being displayed in a serial window.
3.5
Thanks a lot…. it’s simply perfect! It seems “tailor-made” for my needs!