Powering Arduino and WS2812B Strips from Car

Hello everyone!

I’m new to the forum so if this isn’t the correct location to post this I’m sorry.

Anyways, I’m hoping you guys with more electrical experience can give me a hand. Over the last few years I’ve gotten big into cars. I have always like the look of sequential/chaser turn signals so I wanted to create some for my car. After doing some research it seemed like using an arduino and some WS2812B strips would be my best option since I have some programming experience and not a whole lot of electrical experience. Anyways, I ordered an arduino uno and a strip of LEDs and begin to practice programming for them using the FastLED library and was able to create a pattern that I liked.

Now I’ve run into my first real roadblock. Since the car’s electrical system uses 12v and both the arduino and LED stip use 5v I’m not to sure what the best course of action is. My plan is to solder wires to the existing plug on the housing and use that as a signal wire to the arduino. While also using some form of constant power to wire the arduino and LEDs. I’m just not sure how to go from 12v to 5v for both the signal power and the constant power. So if anyone has any suggestions that would be great.

Thank you!

TLDR: Need to go from 12v to 5v to power arduino and a WS2812B of LEDs.

I am in a similar situation, lots of programming experience but very little hardware knowledge. I am also building some circuits using 12v power source (motorcycle) and have been dealing with the same issues. I am getting conflicting opinions but I think you can do what you want, without any other components, depending on which Aruduino you have and how much current the LEDs draw. On the UNO there is a Vin pin that says it will take up to 12v, but reading the specs (as long as you are <20v you shouldn’t blow anything), it sounds like you would be OK with the volts you would get from your battery/alternator circuit of just over 13v. There is a 5v output pin on the board, but I think it can only go to 1 amp, but it may go higher if you are powering the circuit from the car battery (this is where it is a bit confusing for me).

The other option is to use small voltage regulator component to bring the 12v down to 5v. Again, depending on the amp draw of your LEDs you might need to use Multiple voltage regulators.

Just check everything with a meter before hooking up components so you don’t burn anything up.

Hopefully someone with more experience will jump in and correct me where I am wrong.

Hoe this helps