The circuit explains how to connect an Infrared Sensor to the Microcontroller, the program to control 8 devices through a standard RC5 Remote control.
INCLUDE reg_51.pdf
INPUT EQU P3.2 ; Port3,Bit2 is used as input. The demodulated signal
; with active low level is connected to this pin
RB0 EQU 000H ; Select Register Bank 0
RB1 EQU 008H ; Select Register Bank 1 ...poke to PSW to use
DSEG ; This is internal data memory
ORG 20H ; Bit adressable memory
FLAGS: DS 1
CONTROL BIT FLAGS.0 ; toggles with every new keystroke
NEW BIT FLAGS.1 ; Bit set when a new command has been received
COMMAND: DS 1 ; Received command byte
SUBAD: DS 1 ; Device subaddress
TOGGLE: DS 1 ;Toggle every bit
ANS: DS 1 ;
ADDR: DS 1
STACK: DS 1 ; Stack begins here
CSEG ; Code begins here
;---------==========----------==========---------=========---------
; PROCESSOR INTERRUPT AND RESET VECTORS
;---------==========----------==========---------=========---------
ORG 00H ; Reset
JMP MAIN
ORG 0003H ; External Interrupt0
JMP RECEIVE
;---------==========----------==========---------=========---------
; ---------==========----------==========---------=========---------
; Interrupt 0 routine
; ---------==========----------==========---------=========---------
RECEIVE:
CPL P2.2
MOV 2,#235 ; Time Loop (3/4 bit time)
DJNZ 2,$ ; Waste Time to sync second bit
MOV 2,#235 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
Mov 2,#134 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
clr a
mov r6,#07h
pol1: mov c,Input
rlc a
Mov 2,#235 ; Waste time for next BIT
Djnz 2,$
Mov 2,#235 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
Mov 2,#235 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
Mov 2,#105 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
djnz r6,pol1
MOV SUBAD,A
mov r6,#06h
pol2:
mov c,Input
rlc a
Mov 2,#235 ; Waste time for next BIT
Djnz 2,$
Mov 2,#235 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
Mov 2,#235 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
Mov 2,#105 ; Time Loop (3/4 bit time)
Djnz 2,$ ; Waste Time to sync second bit
djnz r6,pol2
Mov COMMAND,A ; Save Command at IRData memory
MOV A,SUBAD
MOV ADDR,A
ANL A,#0FH
MOV SUBAD,A
CJNE A,#03H,ZXC1
MOV A,COMMAND
CPL A
MOV COMMAND,A
AJMP ASZ
ZXC1: MOV A,SUBAD
CJNE A,#00H,ANSS
AJMP ASZ
ASZ: MOV A,ADDR
ANL A,#20H
MOV TOGGLE,A
CJNE A,ANS,ANSS
AJMP WAR
ANSS: JMP ANS1
WAR:
MOV A,COMMAND
CJNE A,#01H,DSP1
CPL P0.0
DSP1: CJNE A,#02H,DSP2
CPL P0.1
DSP2: CJNE A,#03H,DSP3
CPL P0.2
DSP3: CJNE A,#04H,DSP4
CPL P0.3
DSP4: CJNE A,#05H,DSP5
CPL P0.4
DSP5: CJNE A,#06H,DSP6
CPL P0.5
DSP6: CJNE A,#07H,DSP7
CPL P0.6
DSP7: CJNE A,#08H,DSP8
CPL P0.7
DSP8: CJNE A,#0CH,DSP9
MOV P0,#0FFH
DSP9:
MOV ANS,TOGGLE
MOV A,ANS
CPL ACC.5
MOV ANS,A
SETB NEW ; Set flag to indicate the new command
;################################################################
ANS1:
RETI
; ---------==========----------==========---------=========---------
; Main routine. Program execution starts here.
; ---------==========----------==========---------=========---------
MAIN:
MOV SP,#60H
SETB EX0 ; Enable external Interrupt0
CLR IT0 ; triggered by a high to low transition
SETB EA; /* Enable global interrupt */
MOV ANS,#00H ;clear temp toggle bit
CLR NEW
LOO:
JNB NEW,LOO
CLR NEW
AJMP LOO
END
