I am working on a robot using an Arduino Uno R3 and I wanted to have the ability of controlling the Arduino wirelessly, like stopping the Arduino without having to pull the power-plug every time.
I want to know the safest way to connect my Raspberry Pi to the Arduino, without huge risk of voltage going either way badly.
I looked at using i2c and Serial, as per these pages: http://blog.oscarliang.net/raspberry-pi-arduino-connected-i2c/ & http://blog.oscarliang.net/connect-raspberry-pi-and-arduino-usb-cable/. I have yet to look up USB. The reason that I'm asking this question is that on the i2c post it said that I should look out for the voltage difference:
How Does It Work? Is It Safe?
The Raspberry Pi is running at 3.3 Volts while the Arduino is running at 5 Volts. There are tutorials suggest using a level converter for the I2C communication. This is NOT needed if the Raspberry Pi is running as “master” and the Arduino is running as “slave”.
How can I safely connect the RPi as the master and the Arduino as the slave.