Hi,

I just encountered a problem with 4 Bit (No RW) LCD interface on a 16x2.


I am running DT's inst int on a PIC18@40MHz. There are numerous interrupt sources, INT0, CCP1, ADC. 1mS timebase interrupt driven. Only asm (rather than the actual ASM/PBP Int structure I used in my prog) did not help.

The LCD starts putting out garbage when the interrupts are enabled. Especially LCD system commands are noticed to be creating most of the trouble. Increasing command delay upto 5000uS did not help.

Re-Init (Flags = 0) would help occasionally. But then the LCD gets stuck displaying only the first line. The peculiarity is the contrast on line 1 is increased with the blocks getting visible.

I normally use LCDs either in 8BIT or serial. Would try this with DT's any pin.

Any pointers ???