P1.1接LED，輸出低電平時發光。
ORG 0000H
LOOP:
SETB P1.0 ;設置為輸入狀態.
SETB P1.1 ;關閉LED
JNB P1.0, $ ;低電平時原地轉移.
CALL DL10ms ;高電平時就稍稍延時.
JNB P1.0, LOOP ;如果是低電平，就是幹擾，轉移到前面.
CLR P1.1 ;開燈
CALL DL10S
JMP LOOP ;繼續去查看傳感器.
;------------------------------------------------------
DL10ms:
MOV R6, #20
MOV R7, #250
DJNZ R7, $
DJNZ R6, $ - 2
RET
;------------------------------------------------------
DL1s:
MOV R5, #100
D1: CALL DL10ms
DJNZ R5, D1
RET
;------------------------------------------------------
DL10s:
MOV R4, #10
D2: CALL DL1s
DJNZ R4, D2
RET
;------------------------------------------------------
END