STM32串口中断接收一个完整的数据帧
代码运行条件:
(1) 大端发送;
(2) 上位机发送一帧数据的时间间隔不能大于主循环周期;
(3)数据帧满足下面格式:
帧头部(Head) | 类型(Type) | 长度(Length) | 值(Value) | CRC校验 |
2字节 | 1字节 | 1字节 | X字节 | 2字节 |
0xaa 0x55 |
| X |
|
|
- void USART6_Init (void)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- USART_InitTypeDef USART_InitStructure;
- NVIC_InitTypeDef NVIC_InitStructure;
-
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART6,ENABLE);
- RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC,ENABLE); //修改
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;//修改
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
- GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
- GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOC,&GPIO_InitStructure);//修改
-
- GPIO_PinAFConfig(GPIOC,GPIO_PinSource6,GPIO_AF_USART6);//修改
- GPIO_PinAFConfig(GPIOC,GPIO_PinSource7,GPIO_AF_USART6); //修改
-
- NVIC_InitStructure.NVIC_IRQChannel = USART6_IRQn;
- NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
- NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
- NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
- NVIC_Init(&NVIC_InitStructure);
-
- USART_InitStructure.USART_BaudRate = 115200;
- USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
- USART_InitStructure.USART_Mode = USART_Mode_Tx|USART_Mode_Rx;
- USART_InitStructure.USART_Parity = USART_Parity_No;
- USART_InitStructure.USART_StopBits = USART_StopBits_1;
- USART_InitStructure.USART_WordLength = USART_WordLength_8b;
- USART_Init(USART6,&USART_InitStructure);
-
- USART_ITConfig(USART6,USART_IT_RXNE,ENABLE);//打开接收中断
- USART_Cmd(USART6,ENABLE);
- }
- void USART6_IRQHandler()
- {
- unsigned char rCh;
- static char rCnt = 0;
- if(USART_GetITStatus(USART6,USART_IT_RXNE) != RESET)
- {
- rCh = USART_ReceiveData(USART6);
- COM6_RecvBuf[rCnt] = rCh;
- if(rCnt == 0) //帧头0xAA
- {
- rCnt = (0xAA != rCh)?0:rCnt+1;
- }
- else if(rCnt == 1) //帧头0x55
- {
- rCnt = (0x55 != rCh)?0:rCnt+1;
- }
- else if(rCnt == 2) //类型type
- {
- //这里可以根据类型的范围进行如上的处理
- rCnt++;
- }
- else if(rCnt == 3) //长度len
- {
- rCnt++;
- }
- else if(rCnt > 3) //值value
- {
- rCnt++;
- if(rCnt == 6+COM6_RecvBuf[3])
- {
- rCnt = 0;
- memcpy(COM6_RecvBufBck,COM6_RecvBuf,RECV_BUF_SZ);//缓冲
- COM6_RecvFin = 1; //通知主循环处理
- }
- }
- }
- }
- int main(void)
- {
- int i;
- //代码段1
- while(1)//该循环不能太慢,否则数据缓冲区会被部分修改
- {
- //代码段2
- if(COM6_RecvFin == 1)
- {
- COM6_RecvFin = 0;
- CMD_Analysis();//分析接收到的这帧数据
- }
- //代码段3
- }
- return 0;
- }
- //在以后再仔细分析数据接收较快而处理较慢的问题吧,本课题主要讨论的是如何完整的接收一个数据帧,在数据源正确的情况下不丢帧