LCD Interfacing frustration

Hello, in the last time i have made my first steps with arduino. It have had no problems to interface dallas temperature sensors , DS1307 RTC and LED-Displays with SAA1064.

Now i have try 16 * 2 LCD-Displays, i think 6 data-wires and Voltage is no problem. But the displays only show the first line (the second is dark) as 16 Blocks (all pixel). I have try 4 different displays (datasheets say HD44780 compatible) and 2 librarys ( the normal including in arduino) and the 4bit library. All the same. All pages in the internet show the same wiring and the same librarys. i am working wis arduino vers 17.

has anybody some suggestions, i am very frustrated.

kind regards from germany Gerd

You'll want to look up the data sheet on the particular LCD you have. Not just the controller I2C. The arraignment of the pins might be a little different. Just make sure you know which ones are the data, RS, R/W, Enable, and where ground and +5 go.

Now you should only need 4 of the data wires then the RS and enable connected to the arduino.

i have - control the wiring more than 30 times for each display. - used the correct pins and the wiring is exactly that what all schematics say.

i have try the following displays: - Powertip 1602 E - Mytech MOC 16216D - Yeebo BTC-1620J - TC1602E-01

Did you hook up a small potentiometer for the contrast control ?

Your symptoms sounds like you skipped that!!

How are you wiring up the LCD ?, there have been numerous posts on here where it has boiled down to poor connections between the Arduino and the LCD panel. The best way (IMO) for starters is to solder pins to the LCD and plug it into a Breadboard for testing and development.

This is a nice simple starting point :

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

Once you've got it going, I'd ditch the 4bit Library, its a very poor substitute for the official LiquidCrystal library which also works with 4 bits in recent vesions of the IDE.

I work with cheapo displays I find on Ebay, they work for me....

Gerd

But the displays only show the first line (the second is dark) as 16 Blocks (all pixel).

This is the classic example of an LCD that has power but has not been initialized correctly. Lack of initialization can be caused by faulty connections as mentioned above or by incorrect code.

i have - control the wiring more than 30 times for each display. - used the correct pins and the wiring is exactly that what all schematics say.

I don't doubt that you have done all this - but if you did it correctly then the display would be working. This is where the forum can help you, but only if you provide us with more information. A copy of your code and a photo of your setup come to mind.

The Liquid Crystal tutorial at http://arduino.cc/en/Tutorial/LiquidCrystal has been updated. If you connect your display as shown there and cut and paste the code your display should work.

Don't forget that pin 5 (R/W) has to be grounded if you are only using 6 wires between your Arduino and your LCD module.

Don

If your LCD is HD44780 compatible, there's a much easier way... for about $15, I thihnk it was, you can buy a small interface. It drives the LCD. The Arduino tells the interface what is wanted via a simple serial message (one pin used, instead of many).

Details at...

http://sheepdogguides.com/arduino/art8lcd117.htm