LED Sequential Taillights

[dtsnjsn]

Hey guys!

I've been around Arduino for a while, but hardly ever play with it, so I'm still a noob in terms of experience. I've come up with a new project idea that I'd like to use it for. I want to make some programmable LED sequential taillights. My main concern is how to control the LEDs. Obviously there'll be a ton of them, so how would I be able to control each one without assigning each one to a pin? I would assume it's essentially the same as an LED display, but the issue is I would need to come up with my own in order to fit them in the housings properly.

Thanks in advance!

[awneil]

@dtsnjsn

how would I be able to control each one without assigning each one to a pin?

Use the WS2812-type addressable LEDs.

Use "conventional" LEDs connected to drivers which are controlled via I2C, SPI, or whatever

Use multiplexing or Charlieplexing.

[awneil]

Or go old-school and do it mechanically!

1968 Mercury Cougar XR7 at European Motors in Iowa Sequential Turn Signals

[gilshultz]

Turn signals are safety related and are controlled by law in many countries. Be sure to check your liability especially if you are involved in an accident because they failed. There is a good app note AN2689 by ST on automotive electronics. reading it will help you a lot.
https://www.st.com/resource/en/application_note/cd00181783-protection-of-automotive-electronics-from-electrical-hazards-guidelines-for-design-and-component-selection-stmicroelectronics.pdf Vehicles have one of the most nasty electrical environments you can design for.

[dtsnjsn]

I'll have to do some more research on each of these, thank you!

[dtsnjsn]

@gilshultz

Turn signals are safety related and are controlled by law in many countries. Be sure to check your liability especially if you are involved in an accident because they failed. There is a good app note AN2689 by ST on automotive electronics. reading it will help you a lot.
https://www.st.com/resource/en/application_note/cd00181783-protection-of-automotive-electronics-from-electrical-hazards-guidelines-for-design-and-component-selection-stmicroelectronics.pdf Vehicles have one of the most nasty electrical environments you can design for.

Well, right now its just a personal project of mine. I wouldn't intend on selling anything for a while. I just need to know how I can essentially make a large LED display for now.

[EmilyJane]

Addressable white light LEDs are available. If used behind red tail light lenses they might work.

[xfpd]

@dtsnjsn

how to control the LEDs

How to control groups of leds in FastLed Library with Arduino and WS2812B NEOPIXEL

[TomGeorge]

@EmilyJane

Addressable white light LEDs are available. If used behind red tail light lenses they might work.

Here in Australia, ANY flashing lights MUST be AMBER.
Emergency services only are allowed flashing RED, BLUE and WHITE.

USA allows flashing RED direction indicators, madness.

Tom...

[awneil]

Personally, I think these "progressive" indicators are a stupid idea.

The whole point of the flashing is that it grabs the attention^* - so turning that from a distinct flash into a gradual fade-in seems to entirely defeat the object!

This is definitely a case of something that can be done - but shouldn't.

A definite triumph of form over function.

Addendum:

* and a distinct advantage of LEDs is that the on/off is much more distinct - unlike the old filament bulbs that took a while to warm up & cool down.
So why try to deliberately defeat that??