Building custom Led tail lights. Total noob here.

I am making custom LED tail lights. My idea is to have brake/running lights so I need to have it run at 50% and then go up to 100%. Then for the turn signals I wanted a sweeping effect. I am willing to read and learn myself, I just need some resources to learn the best way to do this...

I have a good knowledge of electronics and soldering. Made many custom lighting sets, but never had to dim and use an led controller.

I have an arduino, but am now learning I may need a different micro controller for LED matrices...

Please if someone can point me in the right direction.

PMW is the way to go for the running/brake lights.

As for turning signals, is that road legal? I thought those had to be blinking and not red but yellow.

As for turning signals, is that road legal? I thought those had to be blinking and not red but yellow.

May be a state by state thing, in the USA. In Washington, turn signals can be red or yellow.

I was more concerned about the blinking/sweeping effect.

1964 Thunderbird

My idea is to have brake/running lights so I need to have it run at 50% and then go up to 100%. Then for the turn signals I wanted a sweeping effect.

I assume you'll need high-power LEDs... probably 1W? But, if you can get-by with standard (~20mA) "super bright" LEDs, that will simplify things a lot. Have you experimented with LEDs yet to check the brightness?

I have an arduino, but am now learning I may need a different micro controller for LED matrices...

A matrix is one way to do it... The Arduino can drive a matrix, depending on the size of yoru matrix and which Arduino you are using.

How many LEDs are you going to use? My current project is a music driven lighting effect that has 48 individually-addressable "super bright" LEDs driven by six [u]MAX6968[/u] LED driver chips. These chips are driven serially, and can be daisy-chained serially, so you only need 3 microcontroller output lines to control many LEDs. I have a "stereo" set-up, so I'm actually using 4 control lines (separate left & right data lines) from an Arduino Uno to control two banks of 24 LEDs.

There are many different LED driver chips... This particular one can use PWM dimming to dim all of the LEDs as a group. (You can turn on & off the LEDs individually, but all of the on-LEDs have to be dimmed together). I'm not using that feature, but it would work for you in your applicatication.

If you use high-power LEDs, you are probably going to need a separate dimmable constant-current driver circuit for each LED. You can buy or build constant-current LED power supplies. You could control these serially (using shift registers) or with a separate microcontroller-output for each LED. Depending on the number of LEDs, these "high power" LED drivers could get expensive.

Basically, the hardware design & wiring are the hardest part. Not really that big of a deal, but it could be a lot of wiring... It felt like it took me "forever" to solder wires to 48 LEDs, and also solder the wires on the driver-end.

The microcontroller programming is simple... Assuming you've done some programming before.

P.S.

so I need to have it run at 50% and then go up to 100%.

That's easy to experiment with, but I think 50% is not enough contrast/difference... I was guessing 25 or 33%... I looked-up a dual filament bulb and it was 6W & 21W. Both filaments are on in the bright blinker/brake state, so that would be 6W when dim and 27W when bright, or about 22% when dim.

You are absolutely right about the filament bulbs, but LEDs intensities are not linear to the voltage/current like a filament bulb. I wouldn't follow the ratio the filament bulb followed step for step. I would play with the intensities to figure it out completely.

You would also have more luck making daytime-visible taillights by going for at least 1 watt, red beat types or similar LED.