LCD freezing problem with interrupts

[sayzer]

OSC is defined as 40Mhz, where is the config settings?
which pic is this?

[HenrikOlsson]

Completely unrelated to your problem, or perhaps not but anyway.....
Does these constructs really work? Do they even compile:

' FWD/RWD button
IF PORTC.1=%1 THEN
   IF rot=%0 AND run=%0 AND flag4=%0 THEN rot=%1:flag2=%0:flag4=%1
   IF rot=%1 AND run=%0 AND flag4=%0 THEN rot=%0:flag2=%0:flag4=%1
ENDIF

I think you need an ENDIF for each of those IF statements.

[pxidr84]

Completely unrelated to your problem, or perhaps not but anyway.....
Does these constructs really work? Do they even compile:

' FWD/RWD button
IF PORTC.1=%1 THEN
   IF rot=%0 AND run=%0 AND flag4=%0 THEN rot=%1:flag2=%0:flag4=%1
   IF rot=%1 AND run=%0 AND flag4=%0 THEN rot=%0:flag2=%0:flag4=%1
ENDIF

I think you need an ENDIF for each of those IF statements.

I've no problems with that (but I've modified this part to something like that):

if rot=%0 then
if run=%0 then
if flag4=%0 then
rot=%1
flag2=%0
flag4=%1
endif
endif
endif

Yeah, not very readable but take less program space than AND operator. And it works good.

[pxidr84]

OSC is defined as 40Mhz, where is the config settings?
which pic is this?

A special PIC for motor control, it's the PIC18F4431, 10MHz quartz with PLL enabled (so 4*10=40MHz).

[sayzer]

So, while LCDOUT command is being executed, an interrupt is occuring.

To "test" this, you can disable all interrupts before lcdout command and enable them right after.
This is just to see.
But this will definitely effect your motor. It can give you a point anyway.