I need to switch a DC wall adapter on and off with either an Arduino or a Raspberry Pi. I am using a Mosfet to do this. The name Mosfet is an acronym, the full name sounds pretty authoritative ‘metal–oxide–semiconductor field-effect transistor’.
Use an N-Channel MOSFET, a resistor, and a 12V DC power supply. Following this Bildr blog post I was able to do it with both an Arduino and a Raspberry Pi.
I got the Mosfet from sparkfun here. My only confusion was how to read the spec sheet on the Mosfet to determine the voltage neccessary to trip the circuit on/off. The rasberry GPIO pins only carry 3.5V compared to the 5V on the Arduino. The circuit works just fine with either a Raspberry Pi or an Arduino.