relay

extends gpiozero's OutputDevice to control relay boards

dependencies

gpiozero

sudo apt-get update
sudo apt-get install python3-gpiozero

connections

sainsmart 5V 4-channel relay board

link to the board

raspi connections to relay board:
    3.3V -> VCC
    5V -> JD-VCC
    GND -> GND
    GPIO -> IN*

power supply connections to relay terminals:
    +V power supply -> +V power input
    GND power supply -> NO relay terminal (far left when facing the relay terminals) -> GND power input