How to connect a Raspberry pi and a Arduino via serial communication
You want to connect an Arduino board to a raspberry pi board. There are several different ways to do it. It can be done with I2C communication, SPI or even the GPIO port on the Raspberry pi. But in this tutorial, we'll use a serial comunication.
But why do we want to connect a raspberry pi 2 B+ and an Arduino uno Rev 3 together? As maybe some of you already know, both of them got their advantages, misadvantages and each of themopen source and open hardware