stm32 USART串口通信
UART初始化函数：
HAL_StatusTypeDef HAL_UART_Init(UART_HandleTypeDef *huart)
参数结构体：
typedef struct { USART_TypeDef *Instance; /*!< UART registers base address */ UART_InitTypeDef Init; /*!< UART communication parameters */ UART_AdvFeatureInitTypeDef AdvancedInit; /*!< UART Advanced Features initialization parameters */ uint8_t *pTxBuffPtr; /*!< Pointer to UART Tx transfer Buffer */ uint16_t TxXferSize; /*!< UART Tx Transfer size */ uint16_t TxXferCount; /*!< UART Tx Transfer Counter */ uint8_t *pRxBuffPtr; /*!< Pointer to UART Rx transfer Buffer */ uint16_t RxXferSize; /*!< UART Rx Transfer size */ uint16_t RxXferCount; /*!< UART Rx Transfer Counter */ uint16_t Mask; /*!< UART Rx RDR register mask */ DMA_HandleTypeDef *hdmatx; /*!< UART Tx DMA Handle parameters */ DMA_HandleTypeDef *hdmarx; /*!< UART Rx DMA Handle parameters */ HAL_LockTypeDef Lock; /*!< Locking object */ __IO HAL_UART_StateTypeDef gState; /*!< UART state information related to global Handle management and also related to Tx operations. This parameter can be a value of @ref HAL_UART_StateTypeDef */ __IO HAL_UART_StateTypeDef RxState; /*!< UART state information related to Rx operations. This parameter can be a value of @ref HAL_UART_StateTypeDef */ __IO uint32_t ErrorCode; /*!< UART Error code */ }UART_HandleTypeDef;
第二个成员的结构体：
typedef struct { uint32_t BaudRate; /*!< This member configures the UART communication baud rate. The baud rate register is computed using the following formula: - If oversampling is 16 or in LIN mode, Baud Rate Register = ((PCLKx) / ((huart->Init.BaudRate))) - If oversampling is 8, Baud Rate Register[15:4] = ((2 * PCLKx) / ((huart->Init.BaudRate)))[15:4] Baud Rate Register[3] = 0 Baud Rate Register[2:0] = (((2 * PCLKx) / ((huart->Init.BaudRate)))[3:0]) >> 1 */ uint32_t WordLength; /*!< Specifies the number of data bits transmitted or received in a frame. This parameter can be a value of @ref UARTEx_Word_Length */ uint32_t StopBits; /*!< Specifies the number of stop bits transmitted. This parameter can be a value of @ref UART_Stop_Bits */ uint32_t Parity; /*!< Specifies the parity mode. This parameter can be a value of @ref UART_Parity @note When parity is enabled, the computed parity is inserted at the MSB position of the transmitted data (9th bit when the word length is set to 9 data bits; 8th bit when the word length is set to 8 data bits). */ uint32_t Mode; /*!< Specifies whether the Receive or Transmit mode is enabled or disabled. This parameter can be a value of @ref UART_Mode */ uint32_t HwFlowCtl; /*!< Specifies whether the hardware flow control mode is enabled or disabled. This parameter can be a value of @ref UART_Hardware_Flow_Control */ uint32_t OverSampling; /*!< Specifies whether the Over sampling 8 is enabled or disabled, to achieve higher speed (up to fPCLK/8). This parameter can be a value of @ref UART_Over_Sampling */ uint32_t OneBitSampling; /*!< Specifies whether a single sample or three samples' majority vote is selected. Selecting the single sample method increases the receiver tolerance to clock deviations. This parameter can be a value of @ref UART_OneBit_Sampling */ }UART_InitTypeDef;
示例：
u8 aRxBuffer[RXBUFFERSIZE];//HAL库使用的串口接收缓冲 UART_HandleTypeDef UART1_Handler; //UART句柄 //初始化IO 串口1 //bound:波特率 void uart_init(u32 bound) { //UART 初始化设置 UART1_Handler.Instance=USART1; //USART1 UART1_Handler.Init.BaudRate=bound; //波特率 UART1_Handler.Init.WordLength=UART_WORDLENGTH_8B; //字长为8位数据格式 UART1_Handler.Init.StopBits=UART_STOPBITS_1; //一个停止位 UART1_Handler.Init.Parity=UART_PARITY_NONE; //无奇偶校验位 UART1_Handler.Init.HwFlowCtl=UART_HWCONTROL_NONE; //无硬件流控 UART1_Handler.Init.Mode=UART_MODE_TX_RX; //收发模式 HAL_UART_Init(&UART1_Handler); //HAL_UART_Init()会使能UART1 HAL_UART_Receive_IT(&UART1_Handler, (u8 *)aRxBuffer, RXBUFFERSIZE);//该函数会开启接收中断：标志位UART_IT_RXNE，并且设置接收缓冲以及接收缓冲接收最大数据量 }
发送数据：
HAL_StatusTypeDef HAL_UART_Transmit(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size, uint32_t Timeout)
第一个参数：句柄 （和HAL_UART_Init的参数相同）
第二个参数：发送数据的数组指针
第三个参数：数组长度
第四个参数：超时时间
