So far I’ve attached devices to my Raspberry Pi or Arduino Uno with ratings less than 100 mA. These devices were connected to the output pins through a transistor or optocoupler. However, for heavy load currents a relay must be used. As a noob, it is somewhat difficult to chose parts with the right specs for driving a relay — so here are some hints.
Continue reading Home automation – Driving a relay with RasPi/ ATtiny