;**********************************************************************
;   This file is a basic code template for assembly code generation   *
;   on the PICmicro PIC16F628. This file contains the basic code      *
;   building blocks to build upon.                                    *  
;                                                                     *
;   If interrupts are not used all code presented between the ORG     *
;   0x004 directive and the label main can be removed. In addition    *
;   the variable assignments for 'w_temp' and 'status_temp' can       *
;   be removed.                                                       *                         
;                                                                     *
;   Refer to the MPASM User's Guide for additional information on     *
;   features of the assembler (Document DS33014).                     *
;                                                                     *
;   Refer to the respective PICmicro data sheet for additional        *
;   information on the instruction set.                               *
;                                                                     *
;   Template file assembled with MPLAB V4.00.00 and MPASM V2.20.12    *
;                                                                     *
;**********************************************************************
;                                                                     *
;    Filename:	    irsony.asm                                        *
;    Date:          5-4-2006                                          *
;    File Version:  1.0                                               *
;                                                                     *
;    Author:        David De Vleeschauwer                             *
;    Company:       http://users.pandora.be/davshomepage              *
;                                                                     * 
;                                                                     *
;**********************************************************************
;                                                                     *
;    Files required:                                                  *
;                                                                     *
;                                                                     *
;                                                                     *
;**********************************************************************
;                                                                     *
;    Notes:                                                           *
;                                                                     *
;                                                                     *
;                                                                     *
;                                                                     *
;**********************************************************************


	list      p=16f628            ; list directive to define processor
	#include <p16f628.inc>        ; processor specific variable definitions
	
	__CONFIG _CP_OFF & _WDT_OFF & _BODEN_ON & _PWRTE_ON & _XT_OSC & _MCLRE_ON & _LVP_OFF

; '__CONFIG' directive is used to embed configuration data within .asm file.
; The lables following the directive are located in the respective .inc file.
; See respective data sheet for additional information on configuration word.






;***** VARIABLE DEFINITIONS
w_temp        	EQU     0x70        ; variable used for context saving 
status_temp   	EQU     0x71        ; variable used for context saving
irerror			EQU		0x72		; variable used for possible errors while receiving
irtimer			EQU		0x73		; variable to save the bitlenght time
ircounter		EQU		0x74		; variable used as a counter for the bits
ircmd			EQU		0x75		; variable wich hold the received command
iradr			EQU		0x76		; variable wich hold the received address
irtemp			EQU		0x77		; variable used for calc ircommand to outputs
delay1			EQU		0x78
delay2			EQU		0X79

led				EQU		0x01		; variable to assign LED output
ir				EQU		0x00		; variable to assign IR input




;**********************************************************************
		ORG     0x000             ; processor reset vector
 		goto    main              ; go to beginning of program


		ORG     0x004             ; interrupt vector location
		movwf   w_temp            ; save off current W register contents
		movf	STATUS,w          ; move status register into W register
		movwf	status_temp       ; save off contents of STATUS register


; isr code can go here or be located as a call subroutine elsewhere


		movf    status_temp,w     ; retrieve copy of STATUS register
		movwf	STATUS            ; restore pre-isr STATUS register contents
		swapf   w_temp,f
		swapf   w_temp,w          ; restore pre-isr W register contents
		retfie                    ; return from interrupt


init	CLRF 	PORTA				;Initialize PORTA by setting
									;output data latches
		BSF		PORTA,LED
		MOVLW 	0X07 				;Turn comparators off and
		MOVWF 	CMCON				;enable pins for I/O
									;functions
		BCF 	STATUS, RP1
		BSF 	STATUS, RP0 		;Select Bank1
		MOVLW 	b'11111101'			;Value used to initialize
									;data direction
		MOVWF 	TRISA 				;Set RA<1> as output
									
		MOVLW 	b'00000000'			;Value used to initialize
									;data direction
		MOVWF 	TRISB 				;Set Rb<7:0> as outputs
									
		BCF		STATUS, RP0			;Select bank 0
		return						;return from subroutine

read_sony   	BSF     irerror,0		;Set the errorbit (will be cleared later when receiving a good code)
            	BCF     INTCON,GIE		;Disable interupts temporary
            	CLRWDT					;Clear the watchdog timer
            	BSF     STATUS,RP0		;Select bank1
            	MOVLW   b'10000101'		;Sets the prescaler and timer
            	MOVWF   OPTION_REG	
            	BCF     STATUS,RP0		;Select bank0
            	BTFSC   PORTA,IR		;If it was just a short parasite on the ir line skip reading code with error.
            	GOTO    end_sony
            	CLRF    TMR0			;Clear timer to measure startbit lenght
sony_st1    	BTFSS   PORTA,IR		;Measure the startbit
            	GOTO    sony_st1
            	MOVF    TMR0,0			;move value of bitlength to irtimer
            	MOVWF   irtimer
            	MOVLW   d'32'			;If startbit lenght less then 2ms then end reading code with error.
            	SUBWF   irtimer,0
            	BTFSS   STATUS,C
            	GOTO    end_sony			
            	MOVLW   d'213'			;If startbit was longer then 2,6ms then end reading code with error.
            	ADDWF   irtimer,0		;Because when not valid startbit ir code is not sony protocol
            	BTFSC   STATUS,C		;So startbit must be between 2ms and 2,6ms.
            	GOTO    end_sony				
            	MOVLW   d'7'			;Set ir counter to receive 7 commandbits.
            	MOVWF   ircounter
rd_sony_cmd 	CLRF    TMR0			;Measure the first part of the bitlength: If if is not between 300 and 900µs
sony_prt1_c 	BTFSC   PORTA,IR		;Then exit inmediatly the routine with an error
            	GOTO    sony_prt1_c
            
				MOVF    TMR0,0
            	MOVWF   IRTIMER
				
            	MOVLW   d'5'
            	SUBWF   irtimer,0
            	BTFSS   STATUS,C
            	GOTO    end_sony
			
            	
				MOVLW   d'241'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    end_sony
            	CLRF    TMR0
				
            	CLRWDT					;Clear the watchdog
sony_prt2_c 	BTFSS   PORTA,IR		;Measure part2 of the command bits and test if the length is between 300 and 1600µs
            	GOTO    sony_prt2_c		;If between these ranges test if second bitpart is shorter or longer than 900µs
            	MOVF    TMR0,0
            	MOVWF   IRTIMER
            	MOVLW   d'5'
            	SUBWF   irtimer,0
            	BTFSS   STATUS,C
            	GOTO    end_sony
            	MOVLW   d'230'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    end_sony
            	MOVLW   d'241'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    sony_its_1
sony_its_0  	BCF     STATUS,C		;if shorter than 900 µs the received bit is a zero
            	RRF     IRCMD,1
            	GOTO    nxt_sony_cmd
sony_its_1  	BSF     STATUS,C
             	RRF     IRCMD,1
nxt_sony_cmd	DECFSZ  ircounter,1		;test if all command bits are processed if not receive next
            	GOTO    rd_sony_cmd		;if longer than 900µs the received bit is a one
            	BCF     STATUS,C
            	RRF     IRCMD,1			;Rotate ircmd one position to become correct command
				
            	MOVLW   d'5'			;set ircounter to receive 5 address bits
            	MOVWF   IRCOUNTER
rd_sony_adr  	CLRF    TMR0
sony_prt1_a  	BTFSC   PORTA,IR		;measure firtst bitlenght if shorter than 300 µs or longer than  900µs
            	GOTO    sony_prt1_a		;then exit inmediatly with error
            	MOVF    TMR0,0
            	MOVWF   IRTIMER
            	MOVLW   d'5'
            	SUBWF   irtimer,0
            	BTFSS   STATUS,C
            	GOTO    end_sony
            	MOVLW   d'241'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    end_sony
            	CLRF    TMR0
            	CLRWDT					;clear watchdog timer
sony_prt2_a  	BTFSS   PORTA,IR		
            	GOTO    sony_prt2_a		;measure second bitlenght if shorter than 300µs or longer than 1600µs
            	MOVF    TMR0,0			;then exit with error
            	MOVWF   IRTIMER			;If between these ranges test if the bit is a one or zero (shorter or longer than 900µs)
            	MOVLW   d'5'
            	SUBWF   irtimer,0
            	BTFSS   STATUS,C
            	GOTO    end_sony
            	MOVLW   d'230'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    end_sony
            	MOVLW   d'241'
            	ADDWF   irtimer,0
            	BTFSC   STATUS,C
            	GOTO    sony_its_1_a
sony_its_0_a   	BCF     STATUS,C		;if second bitpart was shorter than 900µs it's a zero
            	RRF     IRADR,1
            	GOTO    nxt_sony_adr
sony_its_1_a  	BSF     STATUS,C		;if second bitpart was longer than 900µs it's a one
            	RRF     IRADR,1
nxt_sony_adr  	DECFSZ  ircounter,1		;Test if all bits are processed if not receive next
            	GOTO    rd_sony_adr
            	BCF     STATUS,C		;Rotate tree time the iradr to become the correct address
            	RRF     IRADR,1
            	BCF     STATUS,C
            	RRF     IRADR,1
            	BCF     STATUS,C
            	RRF     IRADR,1
            	CLRF    irerror			;Because every bitlength was measured between correct limits no errors occured
				bcf		portA,led

end_sony    	BCF     INTCON,T0IF		;Clear timer0 interrupt flag to avoid an interrupt
            	BSF     STATUS,RP0
            	MOVLW   b'00000101'
            	MOVWF   OPTION_REG
            	BCF     STATUS,RP0
            	RETURN

ir_to_outp		movf	ircmd,W			;Save ircmd in irtemp to prevent loosing the received code
				movwf	irtemp			
				sublw	d'10'			;Check if ir command is higher or equal then 10 if so exit and do nothing
				btfss	STATUS,C
				goto 	end_output
				movf	irtemp,W		;Check if ir command is 9 (button 0) if so clear all outputs
				sublw	d'9'
				btfss	status,Z
				goto	not_button0
				clrf	portB
				goto	end_output				
not_button0		movf	irtemp,W		;Check if ir command is 0 (button1) if so toggle bit 0
				btfss	status,Z
				goto	not_button1
				movlw	b'00000001'
				xorwf	PORTB,1					
				goto	end_output		
not_button1		movf	irtemp,W		;Check if ir command is 1 (button2) if so toggle bit 1
				sublw	d'1'
				btfss	status,Z
				goto	not_button2
				movlw	b'00000010'
				xorwf	PORTB,1
				goto	end_output
not_button2		movf	irtemp,W		;Check if ir command is 2 (button3) if so toggle bit 2
				sublw	d'2'
				btfss	status,Z
				goto	not_button3
				movlw	b'00000100'
				xorwf	PORTB,1
				goto	end_output
not_button3		movf	irtemp,W		;Check if ir command is 3 (button4) if so toggle bit 3
				sublw	d'3'
				btfss	status,Z
				goto	not_button4
				movlw	b'00001000'
				xorwf	PORTB,1
				goto	end_output
not_button4		movf	irtemp,W		;Check if ir command is 4 (button5) if so toggle bit 4
				sublw	d'4'
				btfss	status,Z
				goto	not_button5
				movlw	b'00010000'
				xorwf	PORTB,1
				goto	end_output
not_button5		movf	irtemp,W		;Check if ir command is 5 (button6) if so toggle bit 5
				sublw	d'5'
				btfss	status,Z
				goto	not_button6
				movlw	b'00100000'
				xorwf	PORTB,1
				goto	end_output				
not_button6		movf	irtemp,W		;Check if ir command is 6 (button7) if so toggle bit 6
				sublw	d'6'
				btfss	status,Z
				goto	not_button7
				movlw	b'01000000'
				xorwf	PORTB,1
				goto	end_output
not_button7		movf	irtemp,W		;Check if ir command is 7 (button8) if so toggle bit 7
				sublw	d'7'
				btfss	status,Z
				goto	end_output
				movlw	b'10000000'
				xorwf	PORTB,1
				goto	end_output
end_output			return

delayrout1			movlw	d'255'
				movwf	delay2
looping2			movlw	d'255'
				movwf	delay1
looping1			nop
				nop
				decfsz	delay1,1
				goto	looping1
				decfsz	delay2,1
				goto 	looping2
				return


main				call	init
test				call	read_sony
				btfsc	irerror,1
				goto 	test

				movf	iradr,0
				sublw	d'1'		;<--- Change this value into the value of the deviceaddress
				btfss	status,Z	; Now its for address 1
				goto	test

				call	ir_to_outp
				call	delayrout1
				goto 	test

; remaining code goes here



		END                       ; directive 'end of program'