Working my way through a garage door project. I purchased a few of these but I'll be danged if I can find a consistent answer on how they're wired to a Rpi.
My thought was just start hooking it up and giving it a shot, I'm worried about blowing up my pi though.
There are some sites that say use a pull up, some say use multiple resistors. Some have you connect through ground (which make the least sense to me at all) that reed switch isn't powered, I have no idea how Adafruit's example works.
I assumed I needed power to the the common, then off of the NO/NC post I need to capture the state on a GPIO pin, but I don't really understand where to put the ground? Does it get split off like the multiple resistor link? Does putting the switch to ground engergize the whole circuit that way?
I tried to read some of the posts on here but they're not really getting me to the why. Can someone help me demystify this a bit? If you've got any resources to build some fundamentals I would surely appreciate it. I'm a programmer by trade so I'm out of my element.
I had some confusion on the NO/NC. I think that has cleared up a bit, I was looking at it from the standpoint of my door and not the contact of the switch. The SW should be normally open.
I have three diagrams here and am seeking clarification How do you configure pull up vs pull down with the resistor. Do I need an additional resistor to do the 'pulling' and ensure the safety of my brave #18 GPIO soldier? Does moving the resistor change the properties/functionality of the circuit?
Do I need a smaller resistor? I had a 4.7 on the board already so I used it. Is there a way to calculate an appropriate one? I am not getting a pin change.
So, I understand this is a breach of SO protocol, asking a question on a question but I would rather understand what's going on than just smash one of your answers in and call it done.
When I got a working solution, I tried to scale it up but needed a resistor on each line and switched it to the schematic shown. This works and has not exploded my pi nor has it set on fire.
I'm using a software pulldown and debounce.
What would moving the switch power to the ground side of the resistor do? Nothing?