Potentiometers, +12V systems, and neopixels.

Projects General Guidance
1

Hey, everybody, new user who wants to make something neat!

What I have, are an OSEPP Uno R3 plus that I bought in a kit (same principles and programming), a 100k ohm switch pot that powers a motor speed controller, a and 5k ohm pot that controls a servo controller (vintage air HVAC system) to use as inputs. The intended outputs are a pair of Adafruit neopixel rings and some LED's.

What I'm working on is a climate control panel for a custom car project, so this is a 12-16v system. I want to have the neopixel rings around each pot knob, lighting up as it follows the sweeps of those knobs, changing color as they do (the 5k will be operating a heater control valve).

Is there a way to just branch the signal wires from the pots into the analog pins of the microcontroller, or do I just risk burning out the board because it runs at 5v? I imagine I need a step-down transformer of some sort to run the controller, but I worry about the signals inputs.

2

So, everything is existing and working except the you want to add the Neopixels?

You can use a [u]voltage divider[/u] (2 resistors) to reduce the pot-voltage down to around 5V maximum.

3

Well, after checking voltages, it looks like the motor speed controller's pot has a 5v signal out, so I can probably get away with just branching that to an analog pin. The heater control pot (5k), however, shows source voltage (in this case, 18v as I was using a drill battery for testing).

This is way too high for an input. I'm not sure if I can just reduce the overall voltage going through the pot, as the servo controller would probably just interpret that as the pot stuck at a certain position.

Would a voltage divider work just on the signal, or am I looking at this wrong?