LCD

[Muppet]

Hi

I have been a bit of a muppet and have connected my PIC to my LCD display using the DB0-DB3 data bits not DB4-DB7 as I should have. I have tried using the flexible LCD driver and just put in the pin definitions but no luck. Is it possible to use these pins and force it to work or am I going to have to use some messy jumpers to sort this out?

I am using a PIC18F4520, Batron 20x4 display. Compiler version 4.057.

Thanks for any advice.

[PCM programmer]

See the LCD controller data sheet, on page 8, regarding pins DB0-DB3:
http://www.sparkfun.com/datasheets/LCD/HD44780.pdf

[Muppet]

Thanks PCM, have sorted that out its no messy but connected to the right pins, but I cant seem to get it to work still. I have checked all the connections and everything is fine. I am using DB4-DB7 connected to RB1-RB4, and D0-D2 connected to RS,RW,E respectively. Am using your flexible driver and have set the pins. I am using the BTHQ42003AV-FSTF-LED from farnell. If I leave it running sometimes all the segments go black and you can just about see different segments changing but its not characters just blocks and bits of blocks.

I am new to this and can't work out whats wrong any help would be much appreciated.

[treitmey]

..

[Muppet]

I think that it can be used like this. Another post from 2003 is about using this driver with this LCD http://ccsinfo.com/forum/viewtopic.php?p=68002 I may be wrong though.

[PCM programmer]

Here is the data sheet for the BTHQ42003AV-FSTF-LED:
http://www.farnell.com/datasheets/47112.pdf
It's a 4x20 LCD with an LED backlight.

1. Check the connections. Trace them out carefully on the board. Then
post a list of the pin connections between the PIC and the LCD. The
typical case is, one of the connections is wrong.

2. This LCD uses the HD66712 controller. That controller has a
different set of starting addresses for the rows than the typical LCD.
The Flex driver has some #define statements for these row addresses.
You need to uncomment them, and comment out the normal ones
to make this LCD work.

[Muppet]

Thanks PCM, I checked all connections by toggling the pin and checking the output, turned out I had a via on my board not soldered properly and RS was floating, so it now works....ish.

I am using the lines addresses for the HD66712U but it doesn't seem to be right, I get

[Muppet]

Have looked at it some more and it seems that the last 8 bits of lines 1 and 3 are copied to the first 8 bits of lines 2 and 4. I have tried changing the address to

[Muppet]

I still can't sort this out , any help would be much appreciated.

[PCM programmer]

This post explains what to do:
http://www.avrfreaks.net/index.php?name=PNphpBB2&file=printview&t=12851&start=0
To implement those suggestions, add the 3 entries shown in bold below
to the init string:

[Guest]

PCM programmer you are a legend I could kiss you

It works a treat. Just in case others read this I changed