I know this is not a question about a particular issue but I'm quite confused about the GPIO circuitry and pinout in general.
I am completely new to this field and have no expertise besides some little from school in electronics. I did quite some Python programming before but I wanted to actually "see" things reacting to code in the real world that's why I bought my RPi 2.
But after using some very simple code to control an LED, I moved on to control a button. That's where my problems started.
Can you guys help me with some webpages and videos where you have learned about the GPIOs? I have no idea why I have to declare a pull up/down and no idea what that even is and I don't know which pins have voltage on it which don't. I have no clue about what an I2C is or UART and all that stuff.
I hope you can understand this and don't blame me for posting this rather general question :)