serial LCD 1602 Backpack using PIC16F690 for Hitach HD44780

[richard]

for my money i would let pbp do all the heavy lifting and leverage their nice efficent routines like this

works for 4 or 8 bit mode and all

'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' '
'Name  : 16F690 LCD BACKPACK
' Date  : oct 2025    richard
' Note  : 300 words used  of 2048
' Notes : Serin2 Baud Rate 300 ~ 19200 Intrc_OSC 8Mhz
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
#CONFIG
cfg = _INTRC_OSC_NOCLKOUT 
cfg&= _WDT_OFF
cfg&= _PWRTE_OFF
cfg&= _MCLRE_OFF
cfg&= _CP_OFF
cfg&= _CPD_OFF
cfg&= _BOD_OFF
cfg&= _IESO_OFF
cfg&= _FCMEN_OFF
  __CONFIG cfg
#ENDCONFIG
    DEFINE OSC 8        
    ANSEL = 0           ' Set all pins digital
    ANSELH = 0          ' Set all pins digital
    OPTION_REG.7 = 0    ' PORTA/PORTB pull-ups are enabled by individual port latch values
     
    CLEAR
    DEFINE LCD_BITS 8     'defines the number of data interface lines (4 or 8) 
    DEFINE LCD_DREG PORTC    'defines the port where data lines are connected to
    DEFINE LCD_RSREG PORTB    'defines the port where RS line is connected to
    DEFINE LCD_RSBIT 6     'defines the pin where RS line is connected to 
    DEFINE LCD_EREG PORTB     'defines the port where E line is connected to 
    DEFINE LCD_EBIT 4     'defines the pin where E line is connected 
    DEFINE LCD_COMMANDUS 1500     'defines the delay after LCDOUT statement 
    DEFINE LCD_DATAUS 50         'delay in micro seconds


    B1 var byte 
    Bl var byte 


' 300=3313  600=1646  1200=813  2400=396  4800=188  9600=84  19200=32
    BaudR var byte : baudr = 32 
    
    TRISC = 0 
    TRISA = % 11111110 
    OSCCON = $70
  


    PAUSE 500
    Porta.0 = 1    ' Backlight ON
    
    LCDOUT $FE,1
'    LCDOUT "ready @19200"
@  bsf   LCD_RSREG ,LCD_RSBIT






main:
   serin2 Portb.5,baudr,3,main,[b1]
   if bl then
        if b1 = 0 then 
             porta.0 = 0  ' Back Light OFF
        endif
        if b1 = 8 then 
             porta.0 = 1 ' Back Light ON
        endif
        bl = 0
        goto main
   endif
   if b1 = 255 then 
         bl = 1
         goto main
   endif
   if b1 = 254 then
@  bcf   LCD_RSREG ,LCD_RSBIT
         goto main 
   endif 
@  MOVE?BB _B1,R3
@  L?CALL lcdsend
@  bsf   LCD_RSREG ,LCD_RSBIT
goto main             ' loop back to top

ps forgot to add it is now so easy to add a flash screen on boot