need help with project

the below code

what you show is not code but scribbles

code is commented

Erik

well this is the commented code..

LIGHT    EQU     P2.5  ;initialising variables
DIS1     EQU     P2.7
DIS2     EQU     P2.6
SEN1     EQU     P1.0
SEN2     EQU     P1.1
ORG      00H
;************************************************************************************
;MAIN

MOV  R4,#00H ;initialising count to zero
MOV  R5,#00H ;initialising counter to zero
MOV  P0,#0FFH   ;make P0 output
MOV  P1,#0FFH   ;make P1 input
MOV  P2,#0FFH   ;make P2 output
JNB    SEN1,UPPC ;sensor value is low when obstructed
JNB    SEN2,DOWNC
AJMP DISPLAY    ;loop

UPPC:
        JB  SEN2,DISPLAY ;check for sen2 obstruction
        INC   R4
        CJNE  R4,#01H,UPP1
        SETB   LIGHT ;light switched on
        SETB   DIS1  ;activate display1 transistor
        SETB   DIS2  ;activate display2 transistor
         CALL CONV    ;hex to bcd conversion
        AJMP   DISPLAY

UPP1:
        CALL   CONV
        AJMP DISPLAY


DOWNC:
        JB  SEN1,DISPLAY ;check for sen1 obstruction
         DEC  R4
        CJNE  R4,#00H,DOWN1
        CLR   LIGHT  ;switch off light when ppl leave
        AJMP   DISPLAY

DOWN1:
        CALL    CONV
        AJMP    DISPLAY

;*******************************************************************************
;CONVERSION
CONV:

        MOV   A,R4
        MOV   B,#10d
        DIV      AB ;to get the first bcd digit
        RR        A
        RR        A
        RR        A
        RR        A
        ADD     A,B ;get both digits in 1 register
         MOV     R5,A ;get the bcd number in r5
        RET
;******************************************************
;DISPLAY
DISPLAY:

        MOV    P2, #80H ;selecting display1
        MOV    A, R5    ;move count to accumulator
        ANL     A, #0F0H ;to get only first digit
        CALL   TRANS ;to display the digit
        MOV   P0,A
        CALL    DELAY
        MOV    P2,#40H ;select display2
        MOV    A,R5
        ANL      A,#0FH ;get the second digit of count
        RR         A
        RR         A
        RR         A
        RR         A
        CALL     TRANS ;to display digit
        MOV      P0,A
        CALL     DELAY
        JNB  SEN1,UPPC ;check for another entry
        JNB  SEN2,DOWNC ;check for exit
        AJMP  DISPLAY
;******************************************************
;TO DECIDE THE NUMBER TO BE DISPLAYED
TRANS:
        CJNE    A,#00H,ONE
        MOV    A,#0C0H
        RET
ONE:
        CJNE    A,#10H,TWO
        MOV    A,#0F9H
        RET
TWO:
        CJNE   A,#20H,THREE
        MOV   A,#0A4H
        RET
THREE:
        CJNE     A,#30H,FOUR
        MOV    A,#0B0H
        RET
FOUR:
        CJNE  A,#40H,FIVE
        MOV  A,#99H
        RET
FIVE:
        CJNE   A,#50H,SIX
        MOV   A,#92H
        RET
SIX:
        CJNE   A,#60H,SEVEN
        MOV   A,#82H
        RET
SEVEN:
        CJNE  A,#70H,EIGHT
        MOV  A,#0F8H
        RET
EIGHT:
        CJNE   A,#80H,NINE
        MOV A,#80H
        RET
NINE:
        MOV   A,#98H
        RET
;******************************************************
;DELAY OF 1ms
DELAY:
        MOV   R6,#2
        MOV R7,#230
D1:
        DJNZ  R7,D1
        DJNZ  R6,D1
        RET
END

will be glad if you can make sense of the comments and can help:)
thanks..

Sorry, but I don't have the time to run through the code thoroughly.

This stood out though:

MOV  P0,#0FFH   ;make P0 output
MOV  P1,#0FFH   ;make P1 input
MOV  P2,#0FFH   ;make P2 output

You load all ports with the same 0FFh, but say P0 and P2 are output and P1 is an input. You may want to read the manual to get better understanding of '51 ports.

oh thanks for pointing it out..i gotta look it up once..and if you could spare some time,even if not immediately, i would be happy to take any other suggestions too..thanks a lot for this reply though..will check that out:)

Unlike many other processors, the standard 8051 port does not have a configurable "direction" ("in" or "out")

See: www.8052.com/.../120176

CJNE A,#00H,ONE
MOV A,#0C0H
RET
ONE:

totally misleading label

the CJNE jumps if not zero, there is no determination that the values is one.

also you have no facility for "switch debounce". YES, even a light sensor may need 'debounce', e.g. if low what about 'open legs', e.g. if higher what about swinging arms? also, I have no doubt that you may get two or more pulses if a fur is worn.
A quick look at yor code seens to show that if a person stand still in the lightpath the counter will count and count snd count ....

Erik

@andy neil
ok then do you think we can write the code without specifying the ports as input or output??i mean we remove the following lines..

mov p1,#0ffh
mov p2,#0ffh
mov p3,#0ffh

@erik
well the concept of cjne a,#00h,one is to determine what number available at the counter..if it is not 0 then we check for one and so on upto 9..and the display in each segment does not exceed these 10 digits..so i guess that justifies my display part..coming to the second part of your reply..we have recognised these faults in the circuit at the beginning itself but right now we r jus planning a prototype for our academic curriculum..the points you stated will obviously be the disadvantages of our project:):)we only want to show that when an object obstructs the sensors the counters r incremented or decremented depending on the entry and exit.but right now the increment is happening in huge leaps like it goes from 71 to 82 or decrements from 61 to 54 etc...hope this makes it a bit clear as to what my problem is..

If you read the linked FAQ, it answers that!

FAQ: www.8052.com/.../120176

"i mean we remove the following lines"

If you just remove them without understanding why, then you will almost certainly break something somewhere else in your code!

You need to understand the working of the 8051 ports;
See the above FAQ for a start;

Also: www.8052.com/.../120112

And: http://www.8052.com/tutorial

And probably also: http://www.keil.com/books/8051books.asp

If you jump to the label "TWO" if you have deduced that the number is two, then the label is quote ok.

But if you jump to the label "TWO" to try to figure out if it is two or something higher, then it would be better with a label "TEST_IF_TWO" - right now, it looks more like a promise: "If I jump here, I promise that the number must have the value two."

I stated :"A quick look at yor code seens to show that if a person stand still in the lightpath the counter will count and count snd count"
your problem right now the increment is happening in huge leaps like it goes from 71 to 82 or decrements from 61 to 54 etc...hope this makes it a bit clear as to what my problem is..
is the time "a person stand still in the lightpath"

but right now we r jus planning a prototype for our academic curriculum
so you "jus(t) r (resist) planning", that is VERY obvious. There is ZERO thought behind your code.

Erik