I2C LCD with arduino

[Dan Moos]

I cant seem to find an I2C LCD library that works. Help!

Wish I could offer more details, but Ive spent hours with libraries who's examples won't compile (syntax errors with types and the like), or just make the backlight flash, and nothing else.

I have SDA on analog pin 4
I have SCL on analog pin 5

I have Vcc on +5v
I have GND on GND

I feel dumb that I cant find the solution to what has to be a pretty common task.

[alsetalokin4017]

Have you tried this:
http://forum.arduino.cc/index.php?topic=128635.0

[Dan Moos]

Yeah, that was one of the first libraries I tried. It gave me really weird behavior, especially a frantically blinking back light. Almost like the pins were mis-mapped in the software. Its the one I most wanted to have work too, since it was a drop in replacement for the stock, I2C-less library the IDE comes with.

I did find a library that worked. I stumbled onto the library manager in the IDE and found one that seems to do what it should. So Solved I guess.

I do wish I could get the one you pointed me to going though, as it seems like a more convenient solution if I could get it to work.

[obiwanjacobi]

You have just experienced one of the design problems with most Arduino Libraries. They almost all mix different responsibilities in a single library, namely the knowledge of the LCD (HD44780) protocol and how it is physically connected to the Arduino. This means that you almost always have to hack into libraries to make the work with your specific setup. This will also deter you from updating to a newer (and possibly better) version because of the changes you've made.

But don't be discouraged. There is a lot of info to be found and a lot of people are working on code for the Arduino. The good stuff will rise to the surface.

Good luck with your project.

PS: In my Arduino Template Library (see signature) I attempt to solve this. But this C++ template library is not for the beginner.