LCD cable length?

[Darrel Taylor]

Maybe ...

If the data/RS/E pins are not tri-stated while the power to the VFD is OFF, it could be trying to power it from those pins.
Then when the transistor turns on, it doesn't activate the power-on reset in the display.

When programming with the PICkit, those pins will always tri-state during programming.

Just turning off the transistor without tri-stating all the pins first may not be enough.
Then remember to clear the FLAGS variable, so PBP will re-initialize the display.

[spcw1234]

Probably not your problem, but I spent several hours trying to figure out why my one project would work fine after programming (using USB with a bootloader to program) but after a power cycle it wouldn't work. Program it again and it worked fine until I would do a power cycle again. Turns out when I programmed the bootloader into the PIC I had the extended instruction set enabled. Just a thought.

[Art]

Being the self-educated hack-git that I am, I don't know what either of those suggestions actually are.
BUT, being the self-educated hack-git that I am I figured out you can:
Defeat the 24hr Wikipedia blackout by hitting Ctrl-A followed by Ctrl-C
quickly before the blackout screen appears, then you can paste the entire page to Windows Notepad!

I tried to find out what tri state means... Do I need to use transistors to isolate all of the LCD control pins?
How do you reset the FLAGS var? it is an internal asm variable yes?
Will that ruin my program during execution if my own flags have critical states?

@ spcw1234, I'm not using a bootloader, just plain vanilla PBP hex loaded straight to the pic.

[spcw1234]

Disable java scripting on your browser to use Wikipedia.

http://meta.wikimedia.org/wiki/Engli...ad_blackout.3F

[Art]

It "Appears" I've had some luck by inserting this code:

@   OutputPort  LCD_Port_HNIB    ; Set LCD bus to OUTPUT
    LOW LCD_RS
    HIGH LCD_E
    Char = 3   : gosub  LCDsendShortCOM : @  DelayUS 6000
                 gosub  LCDsendShortCOM : @  DelayUS 1000
                 gosub  LCDsendShortCOM : @  DelayUS 1000
    Char = 2   : gosub  LCDsendShortCOM : @  DelayUS 1000  ; Start 4-bit mode
    Char = $28 : gosub  LCDsendCOM  ; Function Set, 4-bit, 2-line, 5x7
    Char = $0C : gosub  LCDsendCOM  ; Display ON
    Char = $01 : gosub  LCDsendCOM  ; Clear Screen
    Char = $06 : gosub  LCDsendCOM  ; Entry Mode
    LCD_Initialized = 1             ; LCD has been Initialized

after turning the transistor on.

This maybe just rubbish... I'll have to try to get the pic to turn the LCD off and back on again to be sure of anything.

[Art]

Ok, that IS working, I can use the pic to cycle the power to the VFD display ie. turn off, wait three secs,
turn on again and print. I will try to follow any other suggestions to clean it up.

Maybe the LCD controller is recieving power from other lines to keep it running... not sure.

[Darrel Taylor]

That initialization code is already in the LCD_AnyPin file.

To invoke it, simply use this after turning it on.

FLAGS = 0

That tells PBP that the LCD hasn't been initialized yet, and it will do so on the next LCDOUT.