;------------------------------------------------------------------------------- ; ; LCD COMMANDS ;------------------------------------------------------------------------------- ; LCD PINS ; RS R/W DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0 Function (Time) ;------------------------------------------------------------------------------- ; 0 0 0 0 0 0 0 0 0 1 Display clear (1,6ms) ; 0 0 0 0 0 0 0 0 1 x Display, cursor home (1,6ms) ; 0 0 0 0 0 0 0 1 I/D S Entry mode set (40us) ; 0 0 0 0 0 0 1 D C B Display ON/OFF (40us) ; 0 0 0 0 0 1 S/C R/L x x Display/Cursor shift (40us) ; 0 0 0 0 1 DL N x x x Function set (40us) ; 0 0 0 1 ------ CG ADDR ------ CG RAM address set (40us) ; 0 0 1 ------- DD ADDR --------- DD RAM address set (40us) ; 1 0 --------- Write data -------- CG/DD RAM data write (40us) ;------------------------------------------------------------------------------- ; 0 1 BF ----- Address counter --- Busy flag/Addr cnt read (0) ; 1 1 ---------- Read data -------- CG/DD RAM data read (40us) ;------------------------------------------------------------------------------- ; ; I/D=1 Increment, I/D=0 Decrement ; S=1 display shift, S=0 display fix ; D=1 display on, D=0 display off ; C=1 cursor on, C=0 cursor off ; B=1 Character Blink, B=0 No Blink ; S/C=1 display step, S/C=0 Cursor step ; R/L=1 shift Right, R/L=0 Shift left ; DL=1 8 bit, DL=0 4 bit interface ; N=1 2line display, N=0 1 line display ; CG ADDR : Character generator RAM addr. ; DD ADDR : Display Data RAM Addr. ; ;------------------------------------------------------------------------------- List p=16F627 ;Processor type include "P16F627.INC" ;Regs def. __config _CP_OFF &_PWRTE_ON &_WDT_OFF & _INTRC_OSC_NOCLKOUT & _LVP_OFF & _MCLRE_OFF ;------------------------------------------------------------------------------- cblock 0x20 ;variables it_cnt ;1 sec counter second ;second counter stat ;semaphore status counter l_cnt ;loop counter blink ;1 sec blink Port_b ;Shadow of PORTB Pointer flag Timer1 Timer2 Timer3 temp count Displ W_TEMP ;W temp while It STATUS_TEMP ;Status temp while It endc ;------------------------------------------------------------------------------- #define Led blink,0 #define max flag,0 #define E PORTA,0x07 ; Display "E" #define RS PORTA,0x06 ; Display "RS" ;------------------------------------------------------------------------------- org 0x00 ;Reset vector goto Init org 0x04 ;interrupt vector goto Interrupt ;------------------------------------------------------------------------------- Table addwf PCL,F ;Jmp addr + w retlw b'01001000' ;RygGyr retlw b'01001000' ;RygGyr retlw b'01101000' ;RYgGyr retlw b'00010010' ;ryGgyR retlw b'00010010' ;ryGgyR retlw b'00010110' ;ryGgYR ;------------------------------------------------------------------------------- LCD_Table1 addwf PCL,1 dt "Cycle ",0 ; LCD_Table2 addwf PCL,1 dt "State ",0 ; ;------------------------------------------------------------------------------- Interrupt PUSH movwf W_TEMP ; Copy W to TEMP register, swapf STATUS, W ; Swap status to be saved into W movwf STATUS_TEMP ; Save status to STATUS_TEMP register btfss INTCON,INTF ;INT it? goto TMR0_it ;No -> tmr0 It bcf INTCON,INTF ;Clear INTF TMR0_it btfss INTCON,T0IF ;TMR0 It? goto Done_it ;No -> done bcf INTCON,T0IF ;Clear flag TMR0 movlw ~.39 movwf TMR0 ;init TMR0 w. 39 for 10 mS interrupt decfsz it_cnt,F ;Decrement it_cnt goto Done_it ; movlw .100 ; movwf it_cnt ;init it_cnt incf second,F ; movlw 0xFF ; xorwf blink,f ; movlw .10 ; subwf second,w ; bnz Done_it ; clrf second ; incf stat,F ; movlw .6 ; subwf stat,w ; bnz Done_it ; clrf stat ; movlw .4 ; subwf l_cnt,w ; bnz loop_out ; incf l_cnt,F ; loop_out bsf max ; Done_it POP swapf STATUS_TEMP, W ; Swap nibbles in STATUS_TEMP register ; and place result into W movwf STATUS ; Move W into STATUS register ; (sets bank to original state) swapf W_TEMP, F ; Swap nibbles in W_TEMP and place result in W_TEMP swapf W_TEMP, W ; Swap nibbles in W_TEMP and place result into W retfie ;Return to main loop ;------------------------------------------------------------------------------- Init movlw 0x07 ; movwf CMCON ;comparators off clrf PORTA ;Clear PORTA clrf PORTB ;Clear PORTB bsf STATUS,RP0 ;Bank 1 movlw b'00110000' movwf TRISA ;RA0-RA3, RA6-RA7 OUT, RA4-RA5 Input movlw b'00000001' movwf TRISB ;RB7-RB1 OUT, RB0/INT in movlw b'00000111' movwf OPTION_REG ;Prescaler 256 for TMR0, ;RB0/INT falling edge bcf STATUS,RP0 ;Bank 0 clrf second ; clrf stat ; clrf blink ; clrf flag ; ;------------------------------------------------------------------------------- ; LCD Init ; movlw 10 ; 10 ms call Del ; LCD Powerup Wait movlw 0x28 ; 28h, 4 bit interface set call Write_c movlw 10 ; 10 ms call Del ; Busy flag Wait movlw 0x28 call Write_c movlw 0x06 ; 06h, Entry mode set: increment call Write_c movlw 0x0C ; 0dh, Display on, cursor/blink off call Write_c movlw 0x10 ; 10h, Display/cursor shift: cursor call Write_c movlw 2 ; 2 ms delay call Del ; Busy flag Wait ; goto ddone movlw b'01000000' ; CG Address =0 call Write_c movlw 0x28 movwf count clrf temp ddone movlw 0x01 ; 01h, Display clear call Write_c ;------------------------------------------------------------------------------- ; Data to LCD ; movlw 0x80 ; LCD Addr = 0 (+128), First LCD Line call Write_c clrf Pointer Start1 movf Pointer,0 call LCD_Table1 ; Get Character movwf Displ tstf Displ bz st2 movfw Displ call Write ; Put to LCD incf Pointer,1 ; Pointer to Next Char. goto Start1 ; No, Jmp Start1 movlw ~.39 movwf TMR0 ;init TMR0 w. 34 for 10 mS interrupt (39 for 4MHz Xtal) movlw .100 movwf it_cnt ;Init IT Counter movlw b'10110000' movwf INTCON ;Enable RB0/INT , TMR0, GIE ;------------------------------------------------------------------------------- Loop nop movfw PORTB ;Read PORTB andlw b'10000000' ;Mask RB7 movwf Port_b ;Save to mirror movfw stat call Table ;Read actual Outputs andlw b'01111110' ;Mask active Bits iorwf Port_b,w ; movwf PORTB ; goto Loop ;------------------------------------------------------------------------------- st2 movlw 0xC0 ; LCD Addr = 40h (+128), 2nd. Line call Write_c clrf Pointer Start2 movf Pointer,0 call LCD_Table2 movwf Displ tstf Displ ; bz read_tc movfw Displ call Write incf Pointer,1 goto Start2 ;------------------------------------------------------------------------------- ; LCD 4 bit Write Step by Step: ; ----------------- ; 1/ RS, R/W set ; 2/ Data High Nible Out ; 3/ E=1 ; 4/ Delay (100us) ; 5/ E=0 ; 2/ Data Low Nible Out ; 3/ E=1 ; 4/ Delay (100us) ; 5/ E=0 ; Write_c bcf RS Write movwf Displ movlw 0xf0 andwf PORTA,f swapf Displ,w andlw 0x0f iorwf PORTA,f bsf E nop bcf E movlw 0xf0 andwf PORTA,f movfw Displ andlw 0x0f iorwf PORTA,f bsf E nop bcf E call Del100 ; Busy flag Wait bsf RS return ;------------------------------------------------------------------------------- Del100 movlw 29 ; 100us Delay movwf Timer1 Del1 decfsz Timer1,f goto Del1 return ;------------------------------------------------------------------------------- Del1m clrf Timer1 ; 1ms Delay movlw 10 movwf Timer2 Del21 call Del100 decfsz Timer2,f goto Del21 return ;------------------------------------------------------------------------------- Del movwf Timer3 ; Delay = w x 1ms Delr call Del1m decfsz Timer3,f goto Delr return ;------------------------------------------------------------------------------- ;------------------------------------------------------------------------------- ;------------------------------------------------------------------------------- end