步进电机控制之8255A

元器件（80c51芯片，8255A芯片，74ls373锁存芯片，l298驱动芯片，三相六线步进电机，按钮若干，电源）​​

图一

汇编源程序：

ORG 0000H;

LJMP MAIN1;

ORG 0030H;（头文件）

MAIN1:MOV DPTR,#0FF7FH;检测PA口状态

MOV A,#91H;

MOVX @DPTR,A;

MAIN:MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L1;

LJMP MAIN;

L1:CJNE A,#0FEH,LOOP2;

LOOP1:MOV DPTR,#0FF7DH;控制电机正转

MOV A,#01H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L2;

LJMP MAIN;

L2:CJNE A,#0FEH,LOOP2;

MOV DPTR,#0FF7DH;

MOV A,#02H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L3;

LJMP MAIN;

L3:CJNE A,#0FEH,LOOP2;

MOV DPTR,#0FF7DH;

MOV A,#04H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L4;

LJMP MAIN;

L4:CJNE A,#0FEH,LOOP2;

L8:LJMP LOOP1;

LOOP2:MOV DPTR,#0FF7DH;控制电机反转

MOV A,#01H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L5;

LJMP MAIN;

L5:CJNE A,#0FCH,LOOP1;

MOV DPTR,#0FF7DH;

MOV A,#04H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L6;

LJMP MAIN;

L6:CJNE A,#0FCH,LOOP1;

MOV DPTR,#0FF7DH;

MOV A,#02H;

MOVX @DPTR,A;

LCALL DELAY;

MOV DPTR,#0FF7CH;

MOVX A,@DPTR;

CJNE A,#0FFH,L7;

LJMP MAIN;

L7:CJNE A,#0FCH,L8;

LJMP LOOP2;

DELAY:MOV R5,#0H;延时子程序

K1:MOV R6,#02H;

K2:MOV R7,#81H;

K3:NOP;

DJNZ R7,K3;

DJNZ R6,K2;

DJNZ R5,K1;

RET;

END;