LED Indicator - Water Flowing Pattern

Okay guys i know there is more than one way to skin a cat with this job so here is the task:

I have a (Not me a friend) hot rod it has 16 holes across the back for “Indicators” the holes are 8mm in diameter and my friend wants 8 to function for each side now this would be as simple as find some 8mm orange LED’s and wire them with associated components to have 3 wires Left, Right and Gnd but here is the catch he wants the water flow pattern like and i quote “Modern vehicles”.

So i can think of several options for this job, option 1 i use 2 voltage divider on an input of an Atmega328 in a IP65 enclosure with a DC-DC converter for the 5v supply then wire up 16 LED’S to each of the outputs using 0-13 (14) and A0-A1 (2) to give me 16 outputs then use A2-A3 as the two inputs from the indicator stalk and simply program it to turn on 1 LED after another. (Sounds over-complicated.)

Option 2 i see if i can find a 8mm LED with a shift register such as the DIP type equivalent of a single WS2812 and drive them directly from 2 pins. (Don’t think i will be able to find such an LED.)

Option 3 i build a circuit similar to a VU meter using 1 of the IC chips available (Alot of wires to run in the back of a vehicle from each individual LED)

What do you people think would be the easiest solution that i could accomplish for this project really looking for some guidance thanks, Chris.

Standard LEDs probably aren't bright enough to be legal unless there are other turn-signal lights.

[u]The Shift-Out Example[/u] shows you how you can (serially) individually-address an almost unlimited number of LEDs with 3 output pins. Once you can address the LEDs you make any kind of sequencing (or other) pattern you want!

I used six serially addressed [u]MAX6986 chips[/u] to make a "Giant VU meter" with 24 LEDs on each stereo-side. (But, the VU meter is only one of 7 different random effects.) This chip (and there are other similar chips) can drive the LED with more current than a regular shift register, and it has current-limited outputs so the LEDs don't need resistors.

So i can think of several options for this job, option 1 i use 2 voltage divider on an input

Since the "12V" in a car is (somewhat) unregulated, I'd recommend a [u]Over-voltage protection circuit[/u] instead of a voltage divider. And of course, you'll need to 2 inputs for the blinkers and another if you want them to function as break lights.

(Alot of wires to run in the back of a vehicle from each individual LED)

No matter how you do it, 16-LEDs is 32 solder joints and at-least 17 wires. :wink: My project with 48 LED "took forever" to solder & heat-shrink the 96 connections, and the physical/mechanical design I used made it harder.

and i quote "Modern vehicles".

Or, like the 1967 Mercury Cougar. :smiley: