;V-2 
;For electronic scheme see website www.picbasic.nl                                      
;           PIC12F629:                  +--v--+                                         
;                                  +5V  [     ]  GND                                    
;                 STANDBY key |---/--- >[     ]> -[4k7]---NPN transistor IR LED         
;                PROGRAM- key |---/--- >[     ]< ---/---| key VOLUME-                   
;       pull-up! PROGRAM+ key |---/--- >[     ]< ---/---| key VOLUME+                   
;                             -         +-----+         -                               
;Er is ook een Nederlandse versie / There is a Dutch version too                        
;www.picbasic.nl / Frits Kieftenbelt, Raalte, Netherlands (Frizie)                      

DEVICE 12F629
CONFIG INTRC_OSC_NOCLKOUT, WDT_OFF, PWRTE_ON, MCLRE_OFF ;No crystal, no reset
ALL_DIGITAL TRUE

;Normal aliases (constants)
SYMBOL Debounce    = 5        ;mSec: Push button debounce time
SYMBOL ProgramUp   = 32       ;Key Program +
SYMBOL ProgramDown = 33       ;Key Program -
SYMBOL StandBy     = 12       ;Key Stand-by
SYMBOL VolumeUp    = 16       ;Key Volume +
SYMBOL VolumeDown  = 17       ;Key Volume -

;Logical aliases (constants)
SYMBOL AAN         = 0        ;Reversed ON
SYMBOL FALSE       = 0
SYMBOL OFF         = 0
SYMBOL ON          = 1
SYMBOL TRUE        = 1
SYMBOL UIT         = 1        ;Reversed OFF

;Port aliases
SYMBOL IrOut       = GPIO.0   ;Infrared LED. Amplifie via 4k7 resistor to NPN transistor (i.e. BC547 and 47 Ohm to IR-LED)
;         76543210
TRISIO = %11111110
PORTB_PULLUPS ON

;BYTE
DIM Command        AS BYTE    ;Contains the RC5 command code which gonna be send
DIM Cycl_1         AS BYTE    ;For ASM routine
DIM Cycl_2         AS BYTE    ;For ASM routine
DIM Key            AS BYTE    ;Contains the value from the inputs (de push-buttons)
DIM Systeem        AS BYTE    ;Contains the RC5 system code for which device the RC5 code is ment
;BIT
DIM ToggleBit      AS BIT     ;Togglebit from RC5

PORTB = 0
CLEAR
Systeem = 0                   ;Fill here the system address (0 = TV) (Don't define Systeem as a constant alias, because that won't work (Works only when it's 0)

IF GPIO.5 = AAN THEN STOP     ;When the StandBy key is pushed when switch the power on the PIC stops (for re-programming PIC12F629)


;MAIN PROGRAM                                                                                                          
Again:
 REPEAT
   Key = (GPIO & %00111110)   ;Read only the inputs
 UNTIL Key <> 62              ;Wait for key press
 DELAYMS Debounce             ;Debounce time for push-buttons
 IF Key <> (GPIO & %00111110) THEN Again ;Not the same? Then it was probably a glitch, scan buttons Again 

 IF (Key & %00000010) = AAN THEN Command = VolumeDown
 IF (Key & %00000100) = AAN THEN Command = VolumeUp
 IF (Key & %00001000) = AAN THEN Command = ProgramUp
 IF (Key & %00010000) = AAN THEN Command = ProgramDown
 IF (Key & %00100000) = AAN THEN Command = StandBy

 ToggleBit = ToggleBit ^ 1    ;Toggle the RC5 togglebit

 WHILE (GPIO & %00111110) <> 62 ;While button is pressed, keep sending signal
   GOSUB RC5_Code             ;Call RC5 assembler routine
   DELAYMS 82                 ;Pause between the IR-zendingen
 WEND
GOTO Again


;ASSEMBLER ROUTINE                                                                                                      
RC5_Code:
ASM
;Send a complete RC5 code  
 call    TxEenRC5             ;Header
 
 btfss   Command,6            ;Inverted command bit
 call    TxEenRC5
 btfsc   Command,6
 call    TxNulRC5

;Togglebit
 btfsc   ToggleBit 
 call    TxEenRC5
 btfss   ToggleBit          
 call    TxNulRC5

;Systembit (A4,3,2,1,0) Address
 btfsc   Systeem,4
 call    TxEenRC5
 btfss   Systeem,4
 call    TxNulRC5

 btfsc   Systeem,3
 call    TxEenRC5
 btfss   Systeem,3
 call    TxNulRC5

 btfsc   Systeem,2
 call    TxEenRC5
 btfss   Systeem,2
 call    TxNulRC5

 btfsc   Systeem,1
 call    TxEenRC5
 btfss   Systeem,1
 call    TxNulRC5

 btfsc   Systeem,0
 call    TxEenRC5
 btfss   Systeem,0
 call    TxNulRC5

;Commandbit (D5,4,3,2,1,0) Data
 btfsc   Command,5
 call    TxEenRC5
 btfss   Command,5
 call    TxNulRC5

 btfsc   Command,4
 call    TxEenRC5
 btfss   Command,4
 call    TxNulRC5

 btfsc   Command,3
 call    TxEenRC5
 btfss   Command,3
 call    TxNulRC5

 btfsc   Command,2
 call    TxEenRC5
 btfss   Command,2
 call    TxNulRC5

 btfsc   Command,1
 call    TxEenRC5
 btfss   Command,1
 call    TxNulRC5

 btfsc   Command,0
 call    TxEenRC5
 btfss   Command,0
 call    TxNulRC5
return 

;*****************************
;Send a 0 (on-off) 
TxNulRC5
 call    LichtAanRC5
 call    LichtUitRC5 
return 

;*****************************
;Send a 1 (off-on)  
TxEenRC5
 call    LichtUitRC5
 call    LichtAanRC5
return 

;*****************************
;IR-LED off 
LichtUitRC5
 movlw   D'100'               ;RC5 has 100 (255 when xtal = 10MHz) time units from IR-LED off
 movwf   Cycl_2 
LichtUit2RC5
 nop                          ;Short delays
 nop 
 nop
 nop
 nop
 nop
 decfsz  Cycl_2,f 
 goto    LichtUit2RC5 
return 

;*****************************
;IR-LED on (pulsing) 
LichtAanRC5
 movlw   D'32'                ;RC5 gives 32 fast IR-LED pulses for a '1'
 movwf   Cycl_1

;32 Cyclussen from a pause and a pulse
LichtAan1RC5
 ;Pause
 nop
 movlw   D'4'                 ;Time for (15 when Xtal = 10MHz) pause between IR-LED blink 
 movwf   Cycl_2 
LichtAan2RC5
 decfsz  Cycl_2,f 
 goto    LichtAan2RC5 
 ;Pulse 
 bsf     IrOut                ;IR-LED on
 movlw   D'1'                 ;Time for (5 when Xtal = 10MHz) IR-LED blink
 movwf   Cycl_2
LichtAan3RC5                  
 decfsz  Cycl_2,f
 goto    LichtAan3RC5 
 bcf     IrOut                ;IR-LED off
 decfsz  Cycl_1,f 
 goto    LichtAan1RC5
return 
ENDASM

;V-2 update to V-1:
;Systeem as constant (SYMBOL) doesn't work (works only when Systeem = 0)
;By V-2 is Systeem a BYTE-variable