單片機串口發送接收程序，下面是關于GPS_CHECKTIAMER,局部應用程序#define UART_R_LEN  60#define UART_T_LEN  34uchar idata trdata[UART_T_LEN];     //定義串口發送緩沖區uchar idata gpsdata[UART_R_LEN];          //定義GPS數據串口接收緩沖區uchar  *inlast_t = trdata;             //最后放進發送緩沖區的uchar  *outlast_t = trdata;            //最后從發送緩沖區出去的uchar  *inlast_r = gpsdata;            //最后進入接收緩沖區的uchar  *outlast_r = gpsdata;           //最后從接收緩沖區取走的bit  t_empty,t_full,r_empty,r_full;  //緩沖區的狀態標志位bit  new_time,t_finish;              //接收完標志和發送完標志void serail(void) interrupt 4{if(TI)                           //如果發送中斷置位{TI = 0;if(!t_empty)                 //如果發送緩沖區數據沒有發完{SBUF = *outlast_t;          //最后從發送緩沖區出去的字符送SBUFoutlast_t++;           //最后發送字符指針地址增1t_full = 0;            //發送區狀態為未滿if(outlast_t >= (trdata + UART_T_LEN)) //如果最后發送字符的地址超出outlast_t = trdata;           //地址到頂部回到底部if(outlast_t == inlast_t)  //如果最后發送字符的地址為最后進入發送的字符地址t_empty = 1;}else t_finish = 1;} if(RI)                      //如果接收中斷置位{RI = 0;if(~r_full)             //如果接收緩沖區未滿{*inlast_r = SBUF; //最后進入接收緩沖區的字符送SBUFinlast_r++;   //最后進入接收緩沖區的字符地址增1r_empty = 0;  //接收緩沖區為非空if(inlast_r >= (gpsdata + UART_R_LEN))   //如果最后接收字符的地址超出inlast_r = gpsdata;            //地址到頂部回到底部if(inlast_r == outlast_r)    

//如果最后接收字符的地址等于最后從接收區取走的字符地址r_full = 1;       //則接收區滿}} }void loadmsg(uchar *msg, int num)         //把字符串放入發送緩沖區準備發送{int i;for(i=0; i num; i++) {*inlast_t = *msg;       //字符裝入最后進入發送發送緩沖區的內容msg++;          //字符串和緩沖地址同時增1inlast_t++;t_empty = 0;        //未發送完if(inlast_t >= (trdata+UART_T_LEN))inlast_t = trdata;         //地址到頂部回到底部if(inlast_t == outlast_t)t_full = 1;           //發送緩沖區滿}if(t_finish){TI = 1;t_finish = 0;}}uchar getbyte_r(void)         //從接收緩沖區取一個字節{uchar c;while(r_empty);           //當接收緩沖區等待接收ES = 0;       //禁止串行中斷c = *outlast_r;     //最后從接收緩沖區取走的數據賦值給Cr_full = 0;      //接收未滿outlast_r++;     //最后由接收緩沖區取走的數據地址增1if(outlast_r >= (gpsdata + UART_R_LEN))   //如果地址超出outlast_r = gpsdata;     //地址回原處if(outlast_r == inlast_r)    

//如果最后接收字符的地址等于最后從接收區取走的字符地址r_empty = 1;      //接收緩沖區為空ES = 1;        //恢復串行中斷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];   

 //定義時標接收區，所存儲的時標數據為接收緩沖區未作轉換的時標，用來作全局時標的中轉存儲while(!r_empty  !new_time)   //若接收緩沖區非空，且接收未完成{temp = getbyte_r();     //每次while循環依次取入一個字節的接收數據switch(r_state)      

//如果依次取入的數據符合表頭“@@Hb”，r_state位置4，進入取時標及GPS狀態字節{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)   

//在完成有用數據采集后，經過數據轉換，將標準字符存入全局時標緩沖中{ptr = (uint*)(tp+2);    //經轉換數據送時標緩沖區 gps_dt[0] = (*ptr)%100;             //年gps_dt[1] = tp[0];        //月gps_dt[2] = tp[1];           //日gps_dt[3] = tp[4];           //時gps_dt[4] = tp[5];           //分gps_dt[5] = tp[6];           //秒new_time = 1;  } r_state = 0;          //用于判斷的數據歸零，以便下一次取數據}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;}}}