串口多字节接收

 1 /* 数据发送格式：
 2  *   0       1          2             3        4   ...   DataLenth-1  DataLenth
 3  * HEAD1 - HEAD2 - DataLenth(n+1) - data_1 - data_2 - ... - data_n - CheckSum
 4  * CheckSum = HEAD1 + HEAD2 + DataLenth + data_1 + data_2 + ... + data_n
 5  */
 6 
 7 #define FRAME_HEADER1 0xFA    // 定义帧头 1
 8 #define FRAME_HEADER2 0xFA    // 定义帧头 2
 9 unsigned char ReceiveDataBuffer[16] = {FRAME_HEADER1, FRAME_HEADER2, 0x00};
10 unsigned char DataBufferCnt = 0x02;
11 unsigned char CheckSum = FRAME_HEADER1 + FRAME_HEADER2;
12 // 串口接收中断程序
13 void USART_IRQHandler(void)
14 {
15     static unsigned char headBufCnt = 0x00;
16     unsigned char buf;
17 
18     buf = ReadRegisterReceiveBuffer();    // 读接收寄存器数据到缓冲区
19 
20 #if (FRAME_HEADER1 != FRAME_HEADER2)    // 检测帧头，两字节帧头不同
21     if(FRAME_HEADER1 == buf) { headBufCnt = 0x01;}
22     else if(0x00 != headBufCnt)
23     {
24         headBufCnt = 0x00;
25         if(FRAME_HEADER2 == buf)
26         {
27             DataBufferCnt = 0x02;
28             CheckSum = FRAME_HEADER1 + FRAME_HEADER2;
29             return;
30         }
31     }
32 #else    // 检测帧头，两字节帧头相同
33     if(FRAME_HEADER1 == buf) { headBufCnt ++;}
34     else if(headBufCnt >= 2)
35     {
36         headBufCnt = 0x00;
37         DataBufferCnt = 0x02;
38         CheckSum = FRAME_HEADER1 + FRAME_HEADER2;
39     }
40     else { headBufCnt = 0x00;}
41 #endif /* FRAME_HEADER1 != FRAME_HEADER2 */
42     
43     ReceiveDataBuffer[DataBufferCnt] = buf;
44     if((DataBufferCnt-2) < ReceiveDataBuffer[2])
45     {
46         CheckSum += ReceiveDataBuffer[DataBufferCnt];    // 计算校验和
47         DataBufferCnt ++;
48     }
49     else    // 数据接收完毕
50     {
51         if(CheckSum == ReceiveDataBuffer[DataBufferCnt])    // 数据校验成功
52         {
53             // 数据校验完毕且正确
54         }
55         DataBufferCnt = 0x02;
56     }
57 }