Recommended · for beginners
Raspberry Pi: 16 Channel Relay how to with example software for automation projects
Why people recommend it
Followed as a practical guide to wiring a 16-channel relay board to a Raspberry Pi, with example Python scripts to build on.
Watch for: Read the comments on board issues and 5V reaching GPIO
In their words
Then use the python scripts supplied by "skiwithpete" on YouTube, see this video Raspberry Pi: 16 Channel Relay how to with example software for automation projects.
user40773 on raspberrypi.stackexchange.com, Jan 2016. CC BY-SA.
Edit: I looked again at this video, and some comments go in similar direction.
0__ on raspberrypi.stackexchange.com, Aug 2017. CC BY-SA.