JHD404A - LCD - HD44780 Wiring Problem

Forum 2005-2010 (read only) Hardware Interfacing
1

Hy there!

I got a HD44780 LCD (Model JHD404A), found a datasheet to wire it up (4bit mode). But the Test Code isnt working :frowning:

Anyone can help me figuring out the problem?

2

I got a HD44780 LCD

Link?

found a datasheet to wire it up

Same question.

But the Test Code isnt working

The test code? I guess I have the same question...

3

Datasheet: http://www.lcdmodkit.com/specification/LKC-4004-A2.pdf
Module: http://cgi.ebay.com/Character-LCD-Module-LCM-JHD404A-Y-YG-HD44780-/200545027053

by testcode i mean the tutorial code.

4

Realistically we're going to need a good high resolution picture or three of your wiring and the exact sketch you're running. Tutorial doesn't mean much, I know of at least a dozen Arduino HD44780 tutorials all over the internet. If its the examples in the IDE, which one you're running and any modifications would suffice. The majority of HD44780 problems rotate around the connections/ wiring and the contrast arrangements. (10k pot 5v to ground with the wiper to the LCD pin is normal)

5

I will reassembly my project and send some detailed Pictures of it.

Some basic guidance?

6

This is where I started :

http://www.skpang.co.uk/content/view/29/42/

Forget the suggested LCD4bit library and the sketch, its outdated. Use the Hello World example in the IDE and adjust the pin numbers and the screen size :

LiquidCrystal lcd(12, 2, 7, 8, 9, 10);

lcd.begin(40,4);
7

It's the green wire — that's where your problem lies.

8

Well, I fixed my wiring and the samples from Tutorial are working fine.

One more question, is there a limitation in Lines you can use with 4 bit mode?

I have 4 lines on my lcd, but can only modify the top two lines, any suggestions?

9

Well I found out, that the 4x40 Display is using two HD44780 Controller to display the whole spectrum. I guess there is no way to use 4 pins for both controller.

10

I guess there is no way to use 4 pins for both controller.

You need the LiquidCrystal440 library. Use the search button in the upper right corner to find it. You will need one more wire for the second Enable pin, making a total of seven rather than six connections between the LCD and the Arduino.

Don

11

It's the green wire — that's where your problem lies.

I've got to remember this one.

Don