i have a (i think) very simple question.
For my Raspberry i've bought a coin acceptor which needs a 12v power supply,
the wiring is like this:
now i'm quite unsure how i need to connect the Ground of the coin acceptor, do I need to connect it to the "GND" of the pi or to the "-" of the power supply?
Thy
UPDATE:
Could i work like this?
UPDATE 2: Here is another setup with the exact same coin acceptor, but i'm not quite sure about that.
https://jalibu.files.wordpress.com/2014/12/advice_machine.jpg
The Product is a CH-926: https://www.amazon.de/Sintron-M%C3%BCnzpr%C3%BCfer-Acceptor-Selector-Laundromat/dp/B00C16P03I
Edit: Any help?