Hello everyone, I am trying to use the input pins of my RPi. I want to connect a button in one of them, and every time it is pressed, a led will be turned on (which will be connected to another pin, which will be configured as an output). I have seen three possible connections:
1: http://pitando.net/wp-content/uploads/2 ... lsador.png
2: The same as in option 1, but with the electronic components exchanged.
3: The same as in option 1, but with a resistance between the circuit and the input pin.
What is the difference between these and which is more advisable?