I bought on ebay a simple LCD screen with an i2c controller. My purpose is to add a simple output screen to my project TermoPi (a smart thermostat for my home). I found a ready-to-use CPP library called LiquidCrystal_I2C that helps the developer to connect the LCD screen to an Arduino board. I want to use my raspberry Pi with the coocking-hacks.com “Raspberry to arduino shields” , a connection board that export the arduino input-output pins, using the arduino conventions. A developer can use the Arduino coding style and libraries with his RaspberryPi, using ArduPi CPP library and coocking-hacks shield. But the original LiquidCrystal_I2C library is not compatible with ArduPi compatibility library: this library is similiar to arduino SDK…but it’s not arduino SDK:

• LiquidCrystal_I2C refers to Arduino “print.cpp” functions, not available on ArduPI
• ArduPi Wire CPP class implements a different Wire.endTrasmission() function, that close and release the I2C comunication pins (it seems a bug)

After some little changes, LiquidCrystal_I2C is ready to use on RaspberryPi with ArduPI library. You can download the library sources from my Bitbuchet GitHub repository:

https://github.com/sarbyn/liquidcrystal_i2c-for-ardupi