LCD : change DDRAM to the second character set

Guest · Posted: Sun Mar 30, 2008 4:08 am

hello,
I am using Flex LCD driver by PCM Programmer for controlling 16x2 LCD.
According to HD44780 data sheet, there are 2 possible character sets which vary in address of DDRAM.
My question therefore is how to employ the second set instead of the first one.
I guess the modification of the following is to be done, but dont have a clue what exactly:

Guest · Posted: Sun Mar 30, 2008 2:11 pm

or am I wrong? I allege that based on Table 4 in HD44780 datasheet. There are 2 ROM Codes - A00, A02
Can it be switched between them or is it factory programmed?
cheers

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

You have to buy the LCD with the specific character set that you want.
Look at this section in the HD44780 data sheet:

Guest · Posted: Mon Mar 31, 2008 3:56 am

thanks for clarifying

aruna1 · Joined: 14 Oct 2008 Posts: 103

Hi
sorry for reviving this old post. but my question is related to this.
@PCM programmer,

How can we know which chip is used in the lcd module we have?

I have some 16x2 lcd modules but their chips are sealed. is there anyway we can find which ROM address chips have?

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

Display the characters....

Best Wishes

aruna1 · Joined: 14 Oct 2008 Posts: 103

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

Realistically if this is not marked on the unit, it is going to have to be powered up, so just displaying characters is as easy as any other way....

However it normally is part of the part number on the unit.

Best Wishes