Recommended · for beginners
Using Relays and Relay Boards with the Raspberry Pi
Why people recommend it
Explains driving relays and relay boards from Raspberry Pi GPIO pins; people follow it as a wiring tutorial and ask whether 3.3 V logic safely triggers 5 V boards.
Watch for: 3.3 V GPIO driving a 5 V relay board
In their words
I was watching this video where the user explains that he is using Raspberry Pi to trigger the relay board, which requires 5v.
avi on raspberrypi.stackexchange.com, May 2014. CC BY-SA.
