I2C LCD

[midali]

#CONFIG
        __CONFIG _CONFIG1, _FCMEN_OFF & _FOSC_INTOSC & _WDTE_OFF & _MCLRE_OFF & _CP_ON & _IESO_OFF & _BOREN_OFF & _PWRTE_OFF
        __CONFIG _CONFIG2, _PLLEN_OFF & _STVREN_OFF & _LVP_OFF
#ENDCONFIG

OSCCON = %01101010   'sets the internal oscillator to 4Mhz
      
TRISA  = %00000000  
TRISC  = %00000000  
ANSELA = %00000000  
ANSELC = %00000000  

OPTION_REG.7 = 0
WPUA = %00000000
WPUC = %00000011

PORTA = 0  
PORTC = 0
  
SCL   VAR PORTC.0
SDA   var PORTC.1
RESET var PORTC.2 ; IT'S REQUIRED?

cbyte var byte 'CONTROL BYTE FOR DATA
I2C   var byte 'CONTROL BYTE FOR CONTROL CODES

cbyte = 0 'USE TO send a command
I2C   = $7C 'ADDRESS FROM MANUAL ??

main:

I2CWRITE SDA,SCL,I2C,cbyte,[$25] 'contrast
PAUSE 1
I2CWRITE SDA,SCL,I2C,cbyte,["HELLO"] 'print on the first line
pause 3000

goto main
end

[Demon]

It might be working but the lcd might not have high enough contrast.

Usually, V0 is not VDD.

Try a 20K variable resistor, V0 to center pin, VDD to one side, GND to other side.

Now turn resistor and look at LCD for changes.

Edit: also increase pause between writes to lcd in case it needs more time. Try PAUSE500 to test.

Robert

[Demon]

...
Try a 20K variable resistor, V0 to center pin, VDD to one side, GND to other side.
...

You still need VDD to pin 4.

Robert