PIC16F877A装配按下每个按钮实时输入到LCD显示屏？

可能是一个错字：但是5-3＝3？



      以下为原文

    Probably a typo but:
How does 5-3=3?

一般来说，你的程序应该是一个循环，等待按下按钮，增加适当的计数器，如果计数发生变化，更新显示，如果按下ENTER，运行步进电机，循环并再次执行。有很多方法来检测按钮按下（中断，轮询）。一般来说，你需要卸下按钮。



      以下为原文

    Generally your program should be a loop, waiting for button presses, incrementing the appropriate counters, update the display if a count changes, run the stepper motor if ENTER is pressed, loop around and do it all again. There are many ways to detect button presses (interrupts, polling). Generally you will need to debounce the buttons.

这是一段代码。我希望它有帮助。当然，它需要一些改进。STEPS寄存器将始终具有TEMP1和TEMP2或TEMP2和TEMP1.cblock 0x20 TEMP1之间的差异；临时存储CW步骤TEMP2的数量；临时存储CCW步骤STEPS的数量；步骤数量（STEPS=TEMP1-TEMP2）FLAGS；位0指示方向：0-CW，1-C这里是初始化代码------clrf TEMP1 clrf TEMP2 clrf STEPS clrf FLAGStest_CW_button btfsc BTCW;是否按下了CW按钮？转到test_CCW_button;否，分支到test_CCW incf TEMP1,f;是，TEMP1=TEMP1+1movf TEMP2,W;W=TEMP2 subwf TEMP1,W;W=TEMP1-TEMP2 btfss STATUS,C;goto._res;是，分支到._res movwf STEPS;否，STEPS=W=TEMP1-TEMP2 bcf FLAGS，0;指示CW方向调用LCD_UPDATE;调用LCD更新子例程测试_CCW-按钮btfsc BTCCW;是否按下了CCW按钮？转到test_Enter_Button;no,分支到test_Enter incf TEMP2,f;是,TEMP2=TEMP2+1movf TEMP2,W;W=TEMP2 subwf TEMP1,W;W=TEMP1-TEMP2 btfss STATUS,C;goto._res;是，分支到._res movwf STEPS;否，STEPS=W=TEMP1-TEMP2 bcf FLAGS,0;指示CW方向调用LCD_UPDATE;调用LCD更新子例程_Enter_Button btfsc BTENTER;Enter按钮被按下吗?转到test_CW_button;否,分支到test_CW clrf TEMP1 CLRF TEMP2转到Move_.;分支到Move_.._res movf TEMP1,W;W=TEMP1 subwf TEMP2,W;W=TEMP2-TEMP1 movwf STEPS;STEPS=W=TEMP2-TEMP1 bsf FLAGS,0;指示CCW方向调用LCD_UPDATE goto test_CW_button



      以下为原文

    Here's a piece of code. I hope it helps. Of course it need some improvements. The STEPS register will have always the difference between TEMP1 and TEMP2 or TEMP2 and TEMP1.
 
cblock    0x20
    
    TEMP1    ;temporarily stores the number of CW steps
    TEMP2    ;temporarily stores the number of CCW steps
    STEPS    ;number of steps (STEPS = TEMP1 - TEMP2)
    FLAGS    ;bit 0 indicate direction: 0 - CW, 1 - CCW

enc

; --- initialization code here ----


    clrf     TEMP1
    clrf     TEMP2
    clrf     STEPS
    clrf     FLAGS


test_CW_button

    btfsc    BTCW               ;is CW button pressed?
    goto     test_CCW_button    ;no, branch to test_CCW
    incf     TEMP1,f            ;yes, TEMP1 = TEMP1 + 1
    movf     TEMP2,W            ;W = TEMP2
    subwf    TEMP1,W            ;W = TEMP1-TEMP2
    btfss    STATUS,C           ;is the result negative?
    goto     adj_res        ;yes, branch to adj_res
    movwf    STEPS              ;no, STEPS = W = TEMP1 - TEMP2
    bcf      FLAGS,0            ;indicate CW direction
    call     LCD_UPDATE         ;call LCD update subroutine


test_CCW-button

    btfsc    BTCCW              ;is CCW button pressed?
    goto     test_Enter_Button  ;no, branch to test_Enter
    incf     TEMP2,f            ;yes, TEMP2 = TEMP2 + 1
    movf     TEMP2,W            ;W = TEMP2
    subwf    TEMP1,W            ;W = TEMP1-TEMP2
    btfss    STATUS,C           ;is the result negative?
    goto     adj_res        ;yes, branch to adj_res
    movwf    STEPS              ;no, STEPS = W = TEMP1 - TEMP2
    bcf      FLAGS,0            ;indicate CW direction
    call     LCD_UPDATE         ;call LCD update subroutine

test_Enter_Button

    btfsc    BTENTER            ;is Enter button pressed?
    goto     test_CW_button     ;no, branch to test_CW
    clrf     TEMP1
    CLRF     TEMP2    
    goto     Move_Motor         ;branch to Move_Motor

adj_res

    movf     TEMP1,W            ;W = TEMP1
    subwf    TEMP2,W            ;W = TEMP2 - TEMP1
    movwf    STEPS              ;STEPS = W = TEMP2 - TEMP1
    bsf      FLAGS,0            ;indicate CCW direction
    call     LCD_UPDATE
    goto     test_CW_button

在这里：



      以下为原文

   
Here:
   cblock  0x20
        STEPS                     ;number of steps (positive = CW, negative = CCW)
    enc
; --- initialization code here ----
start
        clrf    STEPS
test_CW_button
        btfsc   BTCW              ;is CW button pressed?
        goto    test_CCW_button   ;no, branch to test_CCW
        incf    STEPS,f
        call    LCD_UPDATE        ;call LCD update subroutine
test_CCW-button
        btfsc   BTCCW             ;is CCW button pressed?
        goto    test_Enter_Button ;no, branch to test_Enter
        decf    STEPS,f
        call    LCD_UPDATE        ;call LCD update subroutine
test_Enter_Button
        btfsc   BTENTER           ;is Enter button pressed?
        goto    test_CW_button    ;no, branch to test_CW
        call    Move_Motor        ;branch to Move_Motor
        goto    start