SparkFun Forums

[ph0rkeh]

Hey guys, I am having a realy hard time getting my new sparkfun LCD to work with my AVR projects, if any of you have used the sf LCD+AVRs please help me out and look at my code, and my shematic and tell me if theres anything wrong:

http://temp.ph0rkeh.com/avr/lcd/ <-- C Source and Makefile
(Uses peterflurys LCD lib)
http://temp.ph0rkeh.com/avr/lcd/shem.jpg <-- shematic

The prob is All i am getting is a lit first line and the second line isent lit at all, I am away this is a sign that the LCD has not been initd... I have tested all my wires and they seem to be fine, I have even ran trace on my LCD with it taken apart and the db's seem to enter the black epoxy were the chipset is, after that I cannot tell.

FYI: Im running on an atmega16 @ 4MHz crystal on 5volts - Codeing in winAVR libC GCC

edit: has anyone else had a prob with these LCD's before? this is my first time using an LCD i normaly just use USART, but I would like to make some of my projects to be debugged away from a comp... I have tryed multiple source codes / examples and it doesent even flicker.. just sits there like a tard

edit2: might also help uif you know what LCD im running its : http://www.sparkfun.com/commerce/produc ... cts_id=790
blue on yellow 16x2 - hdd7 compat

[transcendentnb2]

Aha! You did the same thing I did! The issue is your port. I haven't looked at your code, but your schematic threw up a red flag to me.

PortC is used by the JTAG and will always be on unless you disable it in the fuse bits. If you take a volt meter to the port, you should notice some odd readings on pins 5 through 2 (forget exactly which). With the JTAG enabled, you can't use those pins for general purpose I/O.

The only way to regain full use of PortC is to disable JTAG through the fuse bits (it is enabled by default). Hopefully you don't need it!

Either that, or more it to a different port.

Hope this fixes it for you. I did the same thing a few months ago and it drove me nuts.