At 09:31 AM 3/30/2004 -0600, Giles Honeycutt wrote:

>Hello all,
>I am reviewing a lot of example LCD code, some very old, some with some good
>and bad features.  Any recommendations for a good reference that
>incorporates:
>4 bit mode
>Uses the busy flag as apposed to delays
>ASM, my target is 16F876A and a 2X16 LCD (actually VFD that emulates LCD)

You might be better off with a different VFD.
The standard 44780 interface has a lot of picky delays that are short enough to be impractical to implement other than as "sit and spin" delays, this makes talking to the display rather time consuming.

Some of the VFD units use a three wire clocked serial interface that is much faster, and easier to implement. Since the delays are much shorter (1-10uS instead of milliseconds) it is less demanding. Also, no nasty init sequence to deal with.

I've not found the busy flag on LCDs to be very reliable. Some work, some don't. Maybe I just got lucky.. :)

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body