LCD Question

[vk6bgn]

Just curious if anyone has any experience with a 2 x 16, blue, backlit LCD made by TinSharp. Say it has a SPLC780 D1 controller in it. (is it a non standard controller???) I was given a few of these (new old stock) a couple years ago and thought I'd use one yesterday. I can't seem to get it to initialize. Can't even get any gibberish on it let alone a "Hello World".

Tried heaps of different code, but no go.

I'm not the greatest at LCD's but I've had a few projects in the past that used serial and parallel LCD's and never had any issue. Pretty straight forward stuff. I think it's an initialization problem. Anyone familiar with a Tinsharp 2 by 16 LCD, model TC1602A-09T.

28X2
8 bit mode
DB0 - B.0 , DB1 - B.1..... DB7 - B.7

Enable - C.7
R/S - C.6
R/W - Low (connected to 0V)


Thanks

 

[Goeytex]

I have no direct experience with that particular LCD Module. However, the 780 in the name suggest HD44780 compatibility.

The Datasheet can be found at the link below.

http://www.winstar.com.tw/UserFiles/downloads/13511323500823064564.pdf

Looks like a typical HD44780 "compatible" driver chip and has been used by both Winstar, Hantronix and others. I see no reason why it would not work using code proven to work on another 16X2 HD44780 compatible display.

If this is a white on blue display then the characters will not show unless the backllght is on. Suggest you also verify that the contrast voltage is about 500mv (.5 volts) when first setting up. This should get it in the ballpark so that characters can be seen.

If still having problems then consider posting your code so that we can have a look at the initialization routine.

 

[hippy]

Looks like a HD44780 compatible command set to me, the initialisation routines look similar to what would be expected without specifically checking other datasheets.

Without the LCD being initalised adjusting the contrast voltages should show something on the screen.

The only issue I could think of is that some LCD modules have different pinout ordering to others. You would need to post a link to the actual module for that to be checked.

 

[inglewoodpete]

First two steps with LCDs like this:

1. Is the backlight working? It should be obvious.
2. Once the module has booted, but not been initialised by your code, do you see a row of 'blocks' instead of characters? If not, adjust the contrast potentiometer so you get these 'blocks' displayed.

If the above points check out OK, try slowing the output signals and check them with a LED+resistor 'test lamp'. Insert 5-second wait statements (Eg Wait 5 or Pause 5000) in the appropriate places in your code. This will give you enough time to check that the pins on the module are getting the appropriate signals. I have found dry solder joints on cheap LCDs from China, too.

 

[Goeytex]

The Manufacturers Datasheet shows a fairly common pinout

 

[vk6bgn]

Goeytex, Hippy, Pete...

Many many thanks for the reply guys. I email the bloke who gave me this (new old stock) blue back lit 2 by 16 LCD and he said that heaps of people had problems getting them to work. Eventually, after two days, I got this one to somewhat work. The contrast is buggered. Seems to be fully on or off. Could never get the cursor to come on or blink and I could only get it to work on the first line. Even after reading the PDF a few times from the link Goeytex provided. So, in the end, I connected a spare standard green 2 x 16 HD44780 compatible LCD and it worked first time. The project is off and running again. Lesson learned... :-(

Again, may thanks for the reply.