What is after the first 1. 2. 3. 4. steps ?

RPI Info RPI 1-Wire ® RPI 1-Wire ® Temperature (DS18B20) RPI i2c. RPI i2c. 16 LED Output (MCP23017)

RPI i2c bus (Inter-Integrated Circuit)

Here is some basic gudelines to i2c

At left bar please choose a project of you choice RPI i2c ....... comming soon

The Raspberry Pi designers swapped over I2C ports between board releases.
Just remember: 512M Pi's use i2c port 1, 256M ones use i2c port 0!
or 256 M + First rev of 512M uses port 0 Second rev of 512 ???