基于51超声波测距器设计

程序清单 以下是用汇编语言编写的超声波测距控制源程序： 采用 AT89S51 12z 晶振 显示缓冲单元在，使用内存 44H、45H、46H 用于计算距离 20H 用于标志 VOUT EQU P1.0 ;脉冲输出端口 *中断入口程序* ORG 0000H LJMP START ORG 0003H LJMP PINT0 ORG 000BH LJMP INTT0 ORG 0013H RETI ORG 001BH LJMP INTT1 ORG 0023H RETI ORG 002BH RETI *主程序* START: MOV SP, #4FH MOV R0, #40H ;4043H 为显示数据存放单元（40 为最高位） MOV R7,#0BH CLEARDISP:MOV R0, #00H INC R0 DJNZ R7, CLEARDISP MOV 20H, #00H MOV TMOD, #21H ;T1 为 8 位自动重装模式，T0 为 16 位定 时器 MOV TH0, #00H ;65ms 初值 MOV TL0, #00H ;40KHz 初值 MOV TH1, #0F2H MOV TL1, #0F2H MOV P0, #0FFH MOV P1, #0FFH MOV P2, #0FFH MOV P3, #0FFH MOV R4, #04H ；超声波脉冲个数控制（为赋值的一半） SETB PX0 SETB ET0 STEB EA CLR 00H SETB TR0 ;开启测距定时器 START1: LCALL DISPLAY JNB 00H, START1 ;收到反射信号时标志位为 1 CLR EA LCALL WORK ；计算距离子程序 SETB EA CLR 00H SETB TR0 ；重新开启测距定时器 MOV R2, #64H ； 测量间隔控制（约 4*100=400ms） LOOP: LCALL DISPLAY DJNZ R2, LOOP SJMP START 1 *中断程序* ;T0 中断，65ms 中断一次 INTT0: CLR EA CLR TR0 MOV TH0, #00H MOV TL0, #00H SETB ET1 SETB EA SETB TR0 ;启动计时器 T0，用以计算超声波 来回时间 SETB TR1 ;开启发超声波用定时器 T1 OUT: RETI ;T1 中断，发超声波用 INTT1: CPL VOUT DJNZ R4,RETIOUT CLR TR1 ；超声波发送完毕，关 T1 CLR ET1 MOV R4,#04H SETB EX0 ；开启接收回波中断 RETIOUT: RETI ;外中断 0，收到回波时进入 PINT0: CLR TR0 ；关计数器 CLR TR1 CLR ET1 CLR EA CLR EX0 MOV 44H, TL0 ；将计数值移入处理单元 MOV 45H, TH0 SETB 00H ；接收成功标志 RETI *延时程序* DL1MS: MOV R6, #14H DL1: MOV R7, #19H DL2: DJNZ R6, DL2 DJNZ R6, DL1 RET *显示程序* ;40H 为最高位，43H 为最低位，先扫描高位 DISPLAY：MOVR1, #40H;G MOVR5,#0F7H;G PLAY:MOVA, R5 MOVP0, #0FFH MOVP2, A MOVA, R1 MOVDPTR, #TAB MOVC A, A+DPTR MOVP0, A LCALL DLIMS INCR1 MOVA, R5 JNBACC.0, ENDOUT;G RRA MOVR5, A AJMPPLAY ENDOUT;MOVP2, #0FFH MOVP0, #0FFH RET TAB; DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H,0FFH,88H,0BFH ；共阳数码管 0 ,1, 2,3,4,5,6,7,8,9,不亮，A, *距离计算程序(=计算值17/1000cm) 近似 WORK:PUSHACC PUSHPSW PUSHB MOVPSW, #18H MOVR3, 45H MOVR2, 44H MOVR1, #00D MOVR0, #17D LCALL MUL2BY2 MOVR3, #03H MOVR2, #0E8H LCALLDIV4BY2 LCALLDIV4BY2 MOV40H, R4 MOVA, 40H JNZJJ0 MOV40H, #0AH ;最高位为 0，不点亮 JJ0:MOVAR0 MOVR4, A MOVAR1 MOVR5 A MOV R3, #00D MOVR2, #100D LCALLDIV4BY2 MOV41H, R4 MOVA, 41H JNZJJ1 MOVA, 40H ；此高位为 0，先看最高位是否为不 亮 SUBB A, #0AH JNZJJ1 MOV41H, #0AH ； 最高位不亮，次高位也不亮 JJ1:MOVA, R0 MOVR4, A MOVA, R1 MOVR5, A MOVR3, #00D MOVR2, #10D LCALL DIV4BY2 MOV42H, R4 MOVA42H JNZJJ2 MOVA, 41H ;次高位为 0，先看次高位是否为不亮 SUBB A, #0AH JNZJJ2 MOV42H, #0AH ；次高位不亮，次高位也不亮 JJ2:MOV43H, R0 POPB POPPSW POPACC RET *两字节无符号数乘法程序 MUL2BY2:CLRA MOVR7, A MOVR6, A MOV R5, A MOVR4, A MOV46H, #10H MULLOOP1:CLRC MOVA, R4 RLCA MOVR4, A MOVA, R5 RLCA MOVR5, A MOVA, R6 RLCA MOVR6, A MOVA, R7 RLCA MOV R7, A MOV A, R0 RLC A MOVR0, A MOVA, R1 RLCA MOVR1, A JNCMULLOOP2 MOVA, R4 ADDA, R2 MOVR4, A MOVA, R5 ADDC A, R3 MOVR5, A MOVA, R6 ADDC A, #00H MOVR6, A MOVA, R7 ADDC A, #00H MOVR7, A MULLOOP2:DJNZ46H, MULLOOP1 RET *四字节/两字节无符号数除法程序* DIV4BY2:MOV46H, #20H MOVR0, #00H MOVR1, #00H DIVLOOP1: MOVA, R4 RLCA MOVR4, A MOVA, R5 RLCA MOVR5, A MOVA, R6 RLCA MOVR6, A MOVA, R7 RLCA MOVR7, A MOVA, R0 RLCA MOVR0, A MOVA, R1 RLCA MOVR1, A CLRC MOVA, R0 SUBB A, R2 MOVB, A MOV A, R1 SUBB A, R3 JCDIVLOOP2 MOVR0, B MOVR1, A DIVLOOP2:CPLC DJNZ46H, DIVLOOP1 MOVA, R4 RLCA MOVR4, A MOVA, R5 RLCA MOVR5, A MOVA, R6 RLCA MOVR6, A MOVA, R7 RLCA MOVR7, A RET ; END 附 C51 程序 #INCLUDE #DEFINE UCHAR UNSIGNED CHAR #DEFINE UINT UNSIGNED INT #DEFINE ULONG UNSIGNED LONG EXTERN VOID CS_T(VOID); EXTERN VOID DELAY(UINT); EXTERN VOID DISPLAY(UCHAR*); /DATA UCHAR DISPLAY(UCHAR*); DATA UCHAR TESTOK; VOID MAIN (VOID) DATA UCHAR DISPRAM5; DATA UINT I; DATA ULONG TIME; P0=0XFF; P2=0XFF; TMOD=0X11; IE=0X80; WHILE (1) CS_T(); DELAY(1); TESTOK=0; EX0=1; ET0=1; WHILE(! TESTOK) DISPLAY(DISPRAM); IF (1=TESTOK) TIME=TH0; TIME=(TIME8)| TL0; TIME*=172; TIME/=10000; DISPRAM0=(UCHAR) (TIME%10); TIME/=10; DISPRAM1=(UCHAR) (TIME%10); TIME/=10; DISPRAM2=(UCHAR) (TIME%10); DISPRAM3=(UCHAR) (TIME/10); IF (0=DISPRAM3) DISPRAM3=17; ELSE DISPRAM 0=16; DISPRAM 1=16; DISPRAM 2=16; DISPRAM 3=16; FOR (I=0;I300;I+) DISPLAY(DISPRAM); VOID CS_R(VOID) INTERRUPT 0 TR0=0; ET0=0; EX0=0; TESTOK=1; VOID OVERTIME(VOID) INTERRUPT 1 EX0=0; TR0=0; ET0=0; TESTOK=2; NAME CS_T ?PR?CS_T?CS_T SEGMENT CODE PUBLIC CS_T RSEG ?PR?CS_T?CS_T CS_T: PUSH ACC MOV TH0, #00H MOV TL0, #00H MOV A, #4D SETB TR0 CS_T1: CPL p1.0 NOP NOP NOP NOP NOP NOP NOP NOP NOP NOP DJNZ ACC,CS_T1 POP ACC RET ; END NAME DELAY ?PR?_DELAY?DELAY SEGMENT CODE PUBLIC _DELAY RSEG ?PR?_DELAY?DELAY _DELAY: PUSH ACC MOV A,R7 JZ DELA1 INC R6 DELA1: MOV R5,#50D DJNZ R5, $ DJNZ R7,DELA1 DJNZ R6,DELA1 POP ACC RET END NAME DISPLAY ?PR?_DISPLAY?DISPLAY SEGMENT CODE ?CO?_DISPLAY?DISPLAY SEGMENT DATA EXTRN CODE (_DELAY) PUBLIC _DISPLAY RSEG ?CO?_DISPLAY?DISPLAY ?_DISPLAY?BYTE: DISPBIT: DS 1 DISPNUM: DS 1 RSEG ?PR?_DISPLAY?DISPLAY _DISPLAY: PUSH ACC PUSH DPH PUSH DPL PUSH PSW INC DISPNUM MOV A,DISPNUM CJNE A,#4D,DISP1 DISP1: JC DISP2 MOV DISPNUM,#00H MOV DISPBIT,#0FEH DISP2: MOV A,R1 ADD A,DISPNUM MOV R0,A MOV A,R0 MOV DPTR,#DISPTABLE MOVC A,A+DPTR MOV P0,A MOV A,DISPNUM CJNE A,#2D,DISP3 CLR P