Need help with 16x2 LCD

kn · Post by kn » August 7th, 2006, 5:35 am

Hi

I have some problem with my lcd.

I got one lcd which is 16x2 with backlight.

the model is ssc2a16 and the datasheet is here
http://www.jaycar.com.au/products_uploaded/QP-5516.pdf

it seems to be hd44780 compatible.

I wired the lcd and start the lcd smartie.

The problem is only the left 8 chars of both rows are right.

the right 8 chars are all black blocks.

check the wiring many times and also change the lpt port from spp to epp to ecp to ecp+epp ect but with no luck

an google find the controller seems to be nt 3881 or similar.

any one can help?

thanks

Post by **caesar** » August 7th, 2006, 8:27 am

Hi!
Just looked at the datasheet and indeed it seems compatible.
But this isn't the issue. Your LCD is broken...
It has three chips (or black blobs) on it's back and one of them, the column controller for the part of screen that has black blocks is broken (or has a PCB trace to it interrupted by a scratch).
Look at the bright side: you got the wiring right!

kn · Post by kn » August 7th, 2006, 10:52 am

Thanks for the help.

However, there are only two black spot on the back, is that the problem?

kn · Post by kn » August 8th, 2006, 2:50 am

Hi

Anyone has used a LCD with NT3881 ?

Is NT3881 really compatible with HD44780?

thanks

_X7JAY7X_ · Post by **_X7JAY7X_** » August 8th, 2006, 4:05 am

After doing a brief google search I can up with this. The addressing is different. The commands and timing is essentially the same as HD44780 but not how it places characters on the LCD panel. This will not work unless you rewrite the driver or make your own. It would probably be easier just to buy a HD44780.

J

kn · Post by kn » August 8th, 2006, 4:19 am

Thanks for your reply, _X7JAY7X_.

I am not sure how to find the difference, could you give me some more advice.

I am not afraid of modified the program cause I have do programming for many years. Of course it is not about LCD.

Anyway, I will really appreciate it if you could give me a bit more info about this so I could go into the right direction

_X7JAY7X_ · Post by **_X7JAY7X_** » August 8th, 2006, 4:53 am

The first place to start is to see what the difference in between and HD44780 and an NT3881 as far as addressing. Then you will have to edit the hd44780 parallel driver using delphi. In there some where should be a start address of where to start printing to the lcd at. All you should have to do it change the addressing around a bit. Sorry I cant be of more help right now. If you need help tommorrow PM me.

J

_X7JAY7X_ · Post by **_X7JAY7X_** » August 8th, 2006, 2:55 pm

I looked at the datasheet you provided for your LCD.

The addressing for your display is as follows:

Line1 128 129 130 ... ... .... (decimal)
Line2 192 193 194 ... ... .... (decimal)

For a HD44780:

Line1 0 1 2 ... ... .... (decimal)
Line2 64 65 66 ... ... .... (decimal)

I am surprised you where getting anything at all. What did you have the LCD set to?

I came across this forum http://www.skwor.com/big-trouble-LCD-no ... 09x587.htm

J

kn · Post by kn » August 8th, 2006, 11:59 pm

Hi,

The wiring is winamp.

LCD LPT

E STROBE
R/W AUTOFB
RS INIT
D1-D8 D1-D8

kn · Post by kn » August 9th, 2006, 12:09 am

HI,

I checked the addressing too.

In my lcd the addressing is as you said from 80 - 8F
In HD44780, it is from 00 - 4F

However, the addressing is 7 bits. the 8th bit is always 1.

like this RS RW D7 D6 D5 D4 D3 D2 D1 D0
0 0 1 * * * * * * *

So effectly is it the same?

_X7JAY7X_ · Post by **_X7JAY7X_** » August 9th, 2006, 3:55 am

Yes D7 will always be 1 because all the addresses are above 128.

J

kn · Post by kn » August 9th, 2006, 5:20 am

Thanks

Anyone can help?