12f675_fuse_about_to_blow!

[LEDave]

Hi Henrik,

Try adding a LED to an unused pin and blink it a few times at start-up. Just to verify that the PIC is still actually executing code.

Will do.

Are you using an extarnal crystal or are you running on the internal oscillator?

Internal oscillator.

It does seem strange that the PIC wrote the test lines to the LCD then stopped when the back-light was fired up. It would be nice if it were something not too serious.

Dave

[LEDave]

Hi Henrik,

I've added the LED and pause to the program and no (unless I've made another mistake) the LED doesn't blink,so program not / stopped running? Program doesn't 'run' with the back-light turned off either.

Here's the code:

ANSEL = %00000000 'Disable analog select so ports work as digital i/o.
CMCON0 = %00000111 'Disable analog comparators.
TRISA = %00000000 'Set PORTA as OUTPUT.
PORTA = %00000000 'Set PORTA pins all low.
TRISC = %00000000 'Set PORTC as OUTPUT.
PORTC = %00000000 'Set PORTC pins all low.

DEFINE LCD_DREG PORTC 'PORTC.0 WILL CONNECT TO DB4, PORTC3 TO DB7
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTC
DEFINE LCD_RSBIT 4 'PORTC.4 CONNECT TO LCD PIN4
DEFINE LCD_EREG PORTC
DEFINE LCD_EBIT 5 'PORTC.5 CONNECT TO LCD PIN6
DEFINE LCD_BITS 4
DEFINE LCD_LINES 4
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 75

DEFINE OSC 4

MAIN:
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 1500
LCDOUT $FE,1,"*Hello WORLD*!"
LCDOUT $FE,$C0,"I't WORKS!"
LCDOUT $FE,$94,"I't WORKS!"
LCDOUT $FE,$d4,"Oh dear it stopped!"
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 50
GOTO MAIN

Dave

[LEDave]

Well I changed the LCD_DATAUS n from 75 to 150 and the led fired up on PORTA.5, still no text on the LCD though.

Dave

[mackrackit]

I would not think DATUS would cause the LED not to work...
Have you adjusted the contrast POT after connecting the back light? Maybe it is just washed out ?

[LEDave]

Hi mackrackit,

Have you adjusted the contrast POT after connecting the back light? Maybe it is just washed out ?

Yes, I've even disconnected the back light but can't see any text now, it hasn't reappeared.

Dave

[LEDave]

I've cracked it...........!!!.....Yippeee.

PIN 5 onto LCD from PIC loose R/W.

Henrik, mackrackit, really sorry to have caused a problem.

The display looks great, bright but not too bright and the text is as clear as clear.
Dave

[mackrackit]

If I only had a dime for everytime something like that has happened to me