I ran into a random problem.
I chucked my breadboard into a drawer to make space for something else I wanted to do. Bring it back out a week later.. and no go.
I discovered when waiting for the busy flag to go low ( pin D7 on the LCD ) that a pull down resistor was required. I found this by probing the pin with a multimeter and seeing that the display started working, same as when probed with a scope. So then I tried a 1M resistor, which works too.
I have tried swapping out the LCD for another identical one, swapping out the pic, checking all the wiring, cap across vdd and vss on both lcd and pic, checked over code to see if it was for sure an input, it was.
While using a pull down resistor makes it work, I cannot seem to find any documentation anywhere which actually states I should need one, and it is bothering me that I don't know why its suddenly requiring one where a week ago it was fine without.
Any ideas on what's going on here?