LCD cable length?

[spcw1234]

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[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.

[Art]

Seems you can ignore the last few posts.. I had the transistor shorted the whole time I was supposed to be turning it on & off!

[Charlie]

A quick thought - rather than try to run ribbon cable around a vehicle, where noise will certainly be an issue, why not simply put a small PIC co-located with the display to communicate with your main device using an (RS232ish) serial link and display it on your display? You only need to run a single wire (or 3 wires if you also want to include power for the device) and it should be cheaper and more robust. You won't need driver devices; simply connect the output pin you choose to use on your main PIC to the input pin you choose to use on the display driver PIC. I've done this for over 30 feet without issues.

[Art]

Couple of reasons, but most importantly, to keep the program cycling fast.
A hardware serial port might overcome the speed issue,
But would make it more difficult to do fancy things with the display.