2272rx.asm

RF decoder coding for decode 2262 RF encode

;PT2272 Chips Decode by 89c2051 (11.0592MHz) with PT2262 use 3.3M osc
;REM - signal received pin
;RECEIVE - Correct Signal Detector
;ENABLE_DETE - Continuous Push Detector
;3AH,3BH - Timer value
;31H,32H - use for 8 bit address code
;33H,30H - use for 4 bit data code, if least 4 bit use at data (only use 33H)
;Address - 31H.0 and 32H.0
;float   - 31H.0=0 32H.0=1
;Bit 1   - 31H.0=1 32H.0=1
;Bit 0   - 31H.0=0 32H.0=0
;Error   - 31H.0=1 32H.0=0
;Each time check the signal 3 times, first use REMOTE, 2 and 3 use REMOTES
;Use Timer1 at 16bit, enable interrupt for timer

$MOD51

          ORG   0000H
          JMP   START
          ORG   001BH
                RETI

START:    MOV   SP,#5FH
          MOV   30H,#00H
          MOV   31H,#00H
          MOV   32H,#00H
          MOV   33H,#00H
          MOV   P1,#00H
          MOV   TMOD,#00010000B
          MOV   IE,#10001000B
RM_LP:    ACALL REMOTE
          MOV   B,33H
          ACALL REMOTES
          MOV   A,33H
          CJNE  A,B,RM_LP
          MOV   B,A
          ACALL REMOTES
          MOV   A,33H
          CJNE  A,B,RM_LP
          MOV   P1,A
          CLR   P3.5
          ACALL DELAY1S
          SETB  P3.5
          AJMP  RM_LP
          
REMOTE:   MOV   3AH,#55                  ; Detect Signal within 50ms
REMOTEA:  MOV   3BH,#250 
REMOTEB:  JB    P3.7,REMOTE0             ; Have a Signal, jump to REMOTE0 
          DJNZ  3BH,REMOTEB
          DJNZ  3AH,REMOTEA 
REMOTE_END_1:
          CLR   20H.0
REMOTE_END:
          RET
 
REMOTE0:  JB    20H.0,REMOTE_END_1       ; Check Button un-release, return 
REMOTES:  MOV   34H,#12                  ; received 12bit code & find the about 10ms high level "Header Code"
          CLR   TF1                      ; Set the high level timer at 8~12ms and waiting for 8ms low level, Maximum (70ms                               
          MOV   TH1,#00H
          MOV   TL1,#00H
          SETB  TR1
REMOTE1:  MOV   3AH,#50 
REMOTE2:  MOV   3BH,#25 
REMOTE3:  JB    P3.7,REMOTE1
          JB    TF1,REMOTE_END
          DJNZ  3BH,REMOTE3
          DJNZ  3AH,REMOTE2              ; Waiting for signal at high level within 4ms
          CLR   TF1 
          MOV   TH1,#0F1H
          MOV   TL1,#0F0H
          SETB  TR1
REMOTE_4: JB    TF1,REMOTE_5             ; If over 12ms is received error, return
          JNB   P3.7,REMOTE_4
          CLR   TR1 
          AJMP  REMOTE6                  
REMOTE_5: AJMP  REMOTE_END
REMOTE6:  MOV   3AH,#00                  ; Waiting 554us for received signal 
          DJNZ  3AH,$                    
          MOV   C,P3.7
          MOV   A,33H                    
          RLC   A 
          MOV   33H,A                    ; Store 1st half bit income signal into 33H
          MOV   A,31H                   
          RLC   A
          MOV   31H,A                    ; Store 1st half bit income signal into 31H     
          CLR   TF1
          MOV   TH1,#0FAH
          MOV   TL1,#099H
          SETB  TR1
RM1:      JB    TF1,REMOTE_END           ; Waiting for 1st half bit fall edge, Time limited 1.5ms
          JB    P3.7,RM1                 ; If over 1.5mS, is error return
          CLR   TR1
          CLR   TF1
          MOV   TH1,#0FAH
          MOV   TL1,#099H
          SETB  TR1
RM2:      JB    TF1,REMOTE_END           ; Waiting for 2nd half bit rise edge, Time limited 1.5ms
          JNB   P3.7,RM2                 ; If over 1.5mS, is error return
          CLR   TR1                       
          MOV   3AH,#00                  ; Waiting 554us for received signal
          DJNZ  3AH,$
          MOV   C,P3.7
          MOV   A,30H                    
          RLC   A
          MOV   30H,A                    ; Store 2nd half bit income signal into 30H
          MOV   A,32H
          RLC   A 
          MOV   32H,A                    ; Store 2nd half bit income signal into 32H
          CLR   TF1
          MOV   TH1,#0FAH
          MOV   TL1,#099H
          SETB  TR1 
RM3:      JB    TF1,RM5                  ; Waiting for 2nd half bit fall edge, Time limited 1.5ms
          JB    P3.7,RM3                 ; If over 1.5mS, is error return
          CLR   TR1
          CLR   TF1
          MOV   TH1,#0FAH
          MOV   TL1,#099H
          SETB  TR1
RM4:      JB    TF1,RM5                  ; Waiting for 2nd half bit rise edge, Time limited 1.5ms
          JNB   P3.7,RM4                 ; If over 1.5mS, is error return
          CLR   TR1 
          DJNZ  34H,REMOTE6              ; Check is not complete received 12 bit signal, if not return to REMOTE6 
          MOV   34H,#4                   ; Put the received signal left shift 4 bit and
          AJMP  REMOTE7                  ; Put 8 bits password into the same location
RM5:      AJMP  REMOTE_END
REMOTE7:  CLR   C
          MOV   A,33H
          RLC   A 
          MOV   33H,A
          MOV   A,31H
          RLC   A
          MOV   31H,A
          CLR   C 
          MOV   A,30H
          RLC   A 
          MOV   30H,A
          MOV   A,32H
          RLC   A 
          MOV   32H,A 
          DJNZ  34H,REMOTE7            ; Put 4 bits data coding from high 4 bit to low 4 bits
          MOV   A,33H 
          SWAP  A 
          MOV   33H,A
          MOV   A,30H
          SWAP  A 
          MOV   30H,A 
          SETB  20H.0
          AJMP  REMOTE_END_1

DELAY1S:
          MOV   R6,#250                ; DELAY 1S
DL2:      MOV   R7,#250
DL1:      DJNZ  R7,DL1
          DJNZ  R6,DL2
          RET

          END