With Raspberry Pi and I2C communication, we can connect the Pi with single or multiple Arduino boards. The Raspberry Pi has only 8 GPIO’s, so it would be really useful to have additional Inputs and outputs by combining the Raspberry Pi and Arduino.
There are many ways of Linking them such as using USB cable and Serial Connection. Why do we choose to use I2C? One reason could be it does not use your serial, USB on the Pi. Given the fact that there are only 2 USB ports, this is definitely a big advantage. Secondly, flexibility. You can easily connect up to 128 slaves with the Pi. Also we can just link them directly without a Logic Level Converter.
In the next article I will be doing some Voice Recognition, if you are interested see here Raspberry Pi Voice Recognition Works Like Siri