串口接收，环形缓冲区+解析
环形缓冲区存储结构体
#define RX_RING_SIZE 256typedef struct {uint8_t buf[RX_RING_SIZE]; // 实际存数据volatile uint16_t head; // 写指针（中断在改），（volatile）防止编译器优化导致 中断/主循环不同步volatile uint16_t tail; // 读指针（主循环在改）
} ring_buf_t;
初始化串口
void USART3_IRQHandler(void);//提前声明串口接收中断
void uart3_Init(u32 baud)
{ GPIO_InitTypeDef GPIO_InitStructure;USART_InitTypeDef USART_InitStructure;NVIC_InitTypeDef NVIC_InitStruct;RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB,&GPIO_InitStructure); GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB,&GPIO_InitStructure); USART_InitStructure.USART_BaudRate = baud; USART_InitStructure.USART_WordLength = USART_WordLength_8b; USART_InitStructure.USART_StopBits = USART_StopBits_1; USART_InitStructure.USART_Parity = USART_Parity_No; USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; USART_Init(USART3, &USART_InitStructure); NVIC_InitStruct.NVIC_IRQChannel = USART3_IRQn;NVIC_InitStruct.NVIC_IRQChannelCmd = ENABLE;NVIC_InitStruct.NVIC_IRQChannelPreemptionPriority = 0;NVIC_InitStruct.NVIC_IRQChannelSubPriority = 1;NVIC_Init(&NVIC_InitStruct);//配置NVICUSART_Cmd(USART3, ENABLE); USART_ITConfig(USART3, USART_IT_RXNE, ENABLE); USART_ITConfig(USART3, USART_IT_ERR, ENABLE);BSP_IntVectSet(BSP_INT_ID_USART3,USART3_IRQHandler);BSP_IntEn(BSP_INT_ID_USART3);}
配置结构体
ring_buf_t rx_ring3 = {0, 0, 0};
串口接收中断(基础)
void USART3_IRQHandler(void)
{if (USART_GetITStatus(USART3, USART_IT_RXNE) != RESET) {uint8_t ch = (uint8_t)USART_ReceiveData(USART3);uint16_t next = (rx_ring3.head + 1) % RX_RING_SIZE;// 如果缓冲区没满，存入 数据if (next != rx_ring3.tail) {rx_ring3.buf[rx_ring3.head] = ch;rx_ring3.head = next;}USART_ClearITPendingBit(USART3, USART_IT_RXNE);}
}
解析函数（放循环，阻塞等待）
void Extract_select_Data(void)//判断数据包
{static uint8_t state_r4 = 0;static uint8_t data_len_r4 = 0;static uint8_t count_r4 = 0;static uint8_t frame_buf[32];// 只要缓冲区里有数据，就一直处理while (rx_ring3.head != rx_ring3.tail) {// 1. 从环形缓冲区读取一个字节 uint8_t ch = rx_ring3.buf[rx_ring3.tail];rx_ring3.tail = (rx_ring3.tail + 1) % RX_RING_SIZE;switch (state_r4){case 0: // 等待帧头if (ch == 0x2A){frame_buf[0] = ch;count_r4 = 1;state_r4 = 1;}break;case 1: // 校验 CMDif (ch == 0x11){frame_buf[count_r4++] = ch;state_r4 = 2;}else{state_r4 = 0; // CMD 不匹配，丢弃}break;case 2: // 校验 LENif (ch == 0x04){data_len_r4 = ch;frame_buf[count_r4++] = ch;state_r4 = 3;}else{state_r4 = 0; // LEN 不匹配，丢弃}break;case 3: // 接收 DATA(4字节) + CRCframe_buf[count_r4++] = ch;// 1(2E) + 1(CMD) + 1(LEN) + 4(DATA) + 1(CRC) = 8if (count_r4 >= 8){/* ========= 业务判断 ========= */uint8_t byte6 = frame_buf[5]; // DATA2if (byte6 & 0x04) // bit2 = 1{select_bit2_flag = 1;//解析结果BLE_TO_MCU_OK_FLAG=1;}else{BLE_TO_MCU_OK_FLAG=0;select_bit2_flag = 0;}/* ============================ */state_r4 = 0; // 准备下一帧}break;default:state_r4 = 0;break;}}
}
清除缓存区
void RingBuf3_ClearAndResetParser(void)
{
// __disable_irq(); // 关中断，保证原子性// 1. 清空环形缓冲区数据memset(rx_ring3.buf, 0, RX_RING_SIZE);// 2. 重置 head/tailrx_ring3.head = 0;rx_ring3.tail = 0;// 3. 重置解析器状态state_r3 = 0;count_r3 = 0;data_len_r3 = 0;pkg_ready = 0;// __enable_irq(); // 重新使能中断
}
