i2c lcd problem NEWBIE WARNING

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1

I am new to arduino and am trying to get a I2C interface working. I think I am close. I've blundered thru the forum and am now more confused than ever... not unexpected for a 73 year old.

I have a 4 line 44780 compliant (?) lcd hooked up to a duemilanove and have verified the address as 0x27 so I think the I2C is working.

I get two lines of black squares the other two are blank. The display flashes in accordance with the delays in both the setup and the loop, but no text.

Perhaps I am using the wrong library as there seen to be many of them....

Here is the code I am using:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4);

void setup()
{
lcd.init();
lcd.backlight();
lcd.setCursor(0,0);
lcd.print("test test test");
delay(1000);
}

void loop()
{
lcd.print("XXXXXXXXXXXXXXXXXXXXXXXXXX");
delay(100);
}

Sorry for the clumsy posting.

2

First of all you should go back to your original post, highlight the part that is code, and then use the 'code button' (seventh from the right above all the smileys).

Second, you should not have anything between the brackets in loop() while you are troubleshooting your LCD setup.

Finally, there are lots of forum topics dealing with I2C adapters for LCDs. They tend to boil down to the following:

You can find a nice tutorial here: --> http://arduino-info.wikispaces.com/LCD-Blue-I2C

Don