单片机串口发送接收程序，下面是关于GPS_CHECKTIAMER,局部应用程序#define UART_R_LEN  60#define UART_T_LEN  34uchar idata trdata[UART_T_LEN];     //定义串口发送缓冲区uchar idata gpsdata[UART_R_LEN];          //定义GPS数据串口接收缓冲区uchar  *inlast_t = trdata;             //最后放进发送缓冲区的uchar  *outlast_t = trdata;            //最后从发送缓冲区出去的uchar  *inlast_r = gpsdata;            //最后进入接收缓冲区的uchar  *outlast_r = gpsdata;           //最后从接收缓冲区取走的bit  t_empty,t_full,r_empty,r_full;  //缓冲区的状态标志位bit  new_time,t_finish;              //接收完标志和发送完标志void serail(void) interrupt 4{if(TI)                           //如果发送中断置位{TI = 0;if(!t_empty)                 //如果发送缓冲区数据没有发完{SBUF = *outlast_t;          //最后从发送缓冲区出去的字符送SBUFoutlast_t++;           //最后发送字符指针地址增1t_full = 0;            //发送区状态为未满if(outlast_t >= (trdata + UART_T_LEN)) //如果最后发送字符的地址超出outlast_t = trdata;           //地址到顶部回到底部if(outlast_t == inlast_t)  //如果最后发送字符的地址为最后进入发送的字符地址t_empty = 1;}else t_finish = 1;} if(RI)                      //如果接收中断置位{RI = 0;if(~r_full)             //如果接收缓冲区未满{*inlast_r = SBUF; //最后进入接收缓冲区的字符送SBUFinlast_r++;   //最后进入接收缓冲区的字符地址增1r_empty = 0;  //接收缓冲区为非空if(inlast_r >= (gpsdata + UART_R_LEN))   //如果最后接收字符的地址超出inlast_r = gpsdata;            //地址到顶部回到底部if(inlast_r == outlast_r)    

//如果最后接收字符的地址等于最后从接收区取走的字符地址r_full = 1;       //则接收区满}} }void loadmsg(uchar *msg, int num)         //把字符串放入发送缓冲区准备发送{int i;for(i=0; i num; i++) {*inlast_t = *msg;       //字符装入最后进入发送发送缓冲区的内容msg++;          //字符串和缓冲地址同时增1inlast_t++;t_empty = 0;        //未发送完if(inlast_t >= (trdata+UART_T_LEN))inlast_t = trdata;         //地址到顶部回到底部if(inlast_t == outlast_t)t_full = 1;           //发送缓冲区满}if(t_finish){TI = 1;t_finish = 0;}}uchar getbyte_r(void)         //从接收缓冲区取一个字节{uchar c;while(r_empty);           //当接收缓冲区等待接收ES = 0;       //禁止串行中断c = *outlast_r;     //最后从接收缓冲区取走的数据赋值给Cr_full = 0;      //接收未满outlast_r++;     //最后由接收缓冲区取走的数据地址增1if(outlast_r >= (gpsdata + UART_R_LEN))   //如果地址超出outlast_r = gpsdata;     //地址回原处if(outlast_r == inlast_r)    

//如果最后接收字符的地址等于最后从接收区取走的字符地址r_empty = 1;      //接收缓冲区为空ES = 1;        //恢复串行中断return c;}uchar r_state = 0;uchar r_byte = 0;uchar gps_chksum= 0;void r_string(void)     // 接收字符串{uint    *ptr;uchar temp;uchar tp[7];   

 //定义时标接收区，所存储的时标数据为接收缓冲区未作转换的时标，用来作全局时标的中转存储while(!r_empty  !new_time)   //若接收缓冲区非空，且接收未完成{temp = getbyte_r();     //每次while循环依次取入一个字节的接收数据switch(r_state)      

//如果依次取入的数据符合表头“@@Hb”，r_state位置4，进入取时标及GPS状态字节{case 0:if(temp == 0x40)   //@r_state = 1;break;case 1:if(temp == 0x40)        //@  {r_state = 2;gps_chksum = 0;}else r_state = 0;break;case 2:if(temp == 0x48)  //H{r_state = 3;gps_chksum = gps_chksum^temp;}else r_state = 0;break;case 3:if(temp == 0x62)  //b{r_state = 4;r_byte = 0;gps_chksum = gps_chksum^temp;}else r_state = 0;break;case 4:if(r_byte == 47){ if(gps_chksum == temp)   

//在完成有用数据采集后，经过数据转换，将标准字符存入全局时标缓冲中{ptr = (uint*)(tp+2);    //经转换数据送时标缓冲区 gps_dt[0] = (*ptr)%100;             //年gps_dt[1] = tp[0];        //月gps_dt[2] = tp[1];           //日gps_dt[3] = tp[4];           //时gps_dt[4] = tp[5];           //分gps_dt[5] = tp[6];           //秒new_time = 1;  } r_state = 0;          //用于判断的数据归零，以便下一次取数据}else{gps_chksum = gps_chksum^temp;if(r_byte 7)tp[r_byte] = temp;else if(r_byte == 38)gps_state = temp;r_byte++;} break;default:break;}}}