so for two days now i have been trying to get this basic HD44780 based 16x4 LCD to work.
I'm running a PIC18F4480 and have the LCD wired up in 4 bit mode to PORTC. Power, ground, and contrast check out w/ multmeter and i can dim the display, etc w/ the contrast pot. i checked my soldering and there are no shorts between pins, etc and i checked continuity from the chip pin to the LCD pin. theyre all good.
im programming my project in C using the C18 compiler. I starded using the included C18 LCD libraries (xlcd.h) and it seems straight forward. i edited the xlcd.h to reflect my hardware setup. Just calling OpenXLCD(config) should get me a blinking cursor.. but nothing but a blank display.
so i fiddled w/ other bits of random C and assembly code out there including Nigel's tutorials. The best icoudl get was random black boxes on the display. no discernable characters. I also got a blinking cursor w/ Nigel's display, but that was all.
So what are some good first places to look in finding the problem? i put LEDs on some of the control pins so i could visually see what was going on there. they seem to be behaving ok. i've read the data sheets and have a decent understanding of how this works.. but i havent written any code from scratch yet.. i figure i should be able to get SOMETHING already written to work.
what the most basic test i can do? Is there anything weird about PORTC i should know about?
Thanks