Wednesday, 14 December 2011

Serial-to-parallel character LCD communication

We're getting close to hooking up all the component parts and testing our Blood Bowl game board. The master chip uses UART/serial to talk to the slave, so we've no easy means of talking to the master chip (in a lot of our 18F-based development we usually hook the chip up to a PC using USB to read data directly from the registers - even if USB won't be used in the final design - but this won't be possible in this case, since we can't run UART and USB together)

Since our game board will include two LCD character displays, we figured we could hook those up and use them to write out debug information during testing. In an attempt to keep as many pins free on our master chip, we're looking at converting an HD44780 parallel display into a serial LCD as in this article:
http://embedded-lab.com/blog/?p=30


So before we go plugging everything together and spending hours wondering why things aren't quite working properly, we're going to make a separate project which concentrates on just displaying the information we want on a 3-wire serial LCD (in our final project we'll be using two 20x4 character displays, one green, one blue. But they're on Santa's Xmas Wishlist and not likely to arrive before the big day, so we'll try things out with an old 2x16 that's lying around in the toolbox).