I am kinda new to a Raspberry Pi (just brought mine before writing this post) but I am looking to see what is the most ideal way for two way communication between an Arduino and a Raspberry Pi (USB, SPI or I2C)?
The reason I am asking is because I need to build a small semi autonomous robot for university and plan on using both the Arduino and Pi to control it. Using the GPIO ports of the Arduino for the motor control and sensors and the Pi for video processing and autonomous part. Both will be on the robot itself. I am pretty good with the arduino but never used a Raspberry Pi before.
So my biggest question is what would be the best form of communication for the two boards taking into account speed and safety (I really don't want to blow the Raspberry Pi up due to the voltage difference). Any help would be greatly appreciated.