I want to cover the rear facia with RGB LEDs

[jgarland79]

I want to cover/replace the tail lights with a laser cut sheet of acrylic, bolted to the car via the tail light screws, and cover that sheet of acrylic with waterproof WS2812B RGB LED strips. Then another laser cut sheet of semi translucent dark gray acrylic to cover the array of LEDs. The LEDs will be hooked up to an Arduino, and the Arduino will get input from the factory wire harness. The tail lights will be completely customizable with software. Any pattern or design you can think of. I'm thinking that the entire rear of the car should light up red for brakes. Maybe I can move the license plate somewhere else?

I've already ordered 19 meters of WS2812B RGB LED strips, and I'm working on a 2D CAD drawing of the rear end of the car for the laser cut parts. Anyone want to help?

36996

[bdmiko]

With that many LEDs your rear bumper could be a TV screen. You could do some cool animations too like making it a scrolling marquee.

This sounds like a fun project but there are a couple of things you will want to be careful of:
* The 12V from the car can be noisy and you will want to optically isolate the input from the brake to the arduino from the car.

* The LEDs in ws2812 strings are chained together serially. If one chip burns out or if you get a break in the wires, all of the LEDs in the chain after the break will stop working. If the first LED in the chain stops, which is common with the ws2812b, then you will not have any brake lights. At the very least I would suggest using multiple arduinos with one arduino controlling each row of LEDs. That way if one LED chip burns out, you will still have brake lights.

* These LEDs use a lot of power, up to 50ma each. If you have 19 meters with 60 LEDs/m that is 1140 LEDs which would draw up to 57 Amps! If you are using 144 LEDs/m you will be drawing 136 Amps. You will have to have multiple dc/dc converters and tie the power into multiple places along the LED strips.

David

[Jonathan]

This sounds like a fun project but there are a couple of things you will want to be careful of:


+ blinding the guy behind you.

[Bitsyncmaster]

If you want a full dot matrix, you will need something else to make up the LEDs. You would need an array so the micro can drive one LED at a time.

[jgarland79]

If you want a full dot matrix, you will need something else to make up the LEDs. You would need an array so the micro can drive one LED at a time.
The WS2812B LEDs can be chained together and addressed individually. You only need one data pin to control them all with a micro controller.

Sent from my Nexus 6 using Tapatalk

[Bitsyncmaster]

The WS2812B LEDs can be chained together and addressed individually. You only need one data pin to control them all with a micro controller.

Sent from my Nexus 6 using Tapatalk

Yes, I have been informed how those LEDs work. It would eliminate the need to matrix LEDs. Guess I'm just to old school and have not played with these new LED strings.

[jgarland79]

I sell these glasses with those same LEDs. http://facebook.com/FutureShades

Sent from my Nexus 6 using Tapatalk

[jgarland79]

I'm about to go get this part laser cut to test the fit.

https://drive.google.com/file/d/0B1MGSXk_1cE-Mmo1cFl3Wng2Z1U/view?usp=sharing

[jgarland79]

Still needs some work.


37043

[jgarland79]

After talking with the guys at the hacker space I went to last night, I've decided to use polycarbonate for the plastic parts. They have a large CNC router they can use to cut out my parts.

[Lwanmtr]

I like the idea or programmable led's..this and the other led project both look cool.

Cant wait to see your lights in action :)

My only thing (and this is just personal preference) is I prefer the regular look of the tail lights over a solid peice.

[jgarland79]

I'm trying to make it a bolt on install, so that you don't have to modify any part of the car to install it, and you will be able to re-install the factory lights at any time.

[Lwanmtr]

Hmm..gives me an idea to see how hard to create a stock looking facade that fits over your design...

[mr_maxime]

I sell these glasses with those same LEDs. http://facebook.com/FutureShades

Sent from my Nexus 6 using Tapatalk

Mine only had 2 LEDs...
37068

[MNT250]

Awesome project, can't wait to see how it turns out. I'm in Seattle as well, would love to see them in person when you get something together.

[jgarland79]

Just seeing how many leds will fit.

37082

[jgarland79]

With that many LEDs your rear bumper could be a TV screen. You could do some cool animations too like making it a scrolling marquee.

This sounds like a fun project but there are a couple of things you will want to be careful of:
* The 12V from the car can be noisy and you will want to optically isolate the input from the brake to the arduino from the car.

* The LEDs in ws2812 strings are chained together serially. If one chip burns out or if you get a break in the wires, all of the LEDs in the chain after the break will stop working. If the first LED in the chain stops, which is common with the ws2812b, then you will not have any brake lights. At the very least I would suggest using multiple arduinos with one arduino controlling each row of LEDs. That way if one LED chip burns out, you will still have brake lights.

* These LEDs use a lot of power, up to 50ma each. If you have 19 meters with 60 LEDs/m that is 1140 LEDs which would draw up to 57 Amps! If you are using 144 LEDs/m you will be drawing 136 Amps. You will have to have multiple dc/dc converters and tie the power into multiple places along the LED strips.

David


I think I'm going to use 5 or 6 of these to provide the amperage I need. http://www.ebay.com/itm/181849944119

I can use one of these to monitor the amperage draw: http://www.kr4.us/attopilot-voltage-and-current-sense-breakout-90a.html

I'm thinking I will use two of these to drive the leds: https://docs.particle.io/datasheets/photon-datasheet/ One for each half of the car. That way if one goes out, then it would be like having a bulb go out on one side of the car.

I might also try doing something like this:

// Adafruit_NeoPixel strip = Adafruit_NeoPixel(PIXEL_COUNT, PIXEL_PIN, PIXEL_TYPE);
row1 strip = Adafruit_NeoPixel(64, 1, WS2812B);
row2 strip = Adafruit_NeoPixel(64, 2, WS2812B);
row3 strip = Adafruit_NeoPixel(64, 3, WS2812B);
row4 strip = Adafruit_NeoPixel(64, 4, WS2812B);
row5 strip = Adafruit_NeoPixel(64, 5, WS2812B);
row6 strip = Adafruit_NeoPixel(64, 6, WS2812B);
row7 strip = Adafruit_NeoPixel(64, 7, WS2812B);
row8 strip = Adafruit_NeoPixel(64, 8, WS2812B);

This way I have the strips isolated so that only 64 leds would go out at a time if there is a failure in the strip.

[Lwanmtr]

The parts look inexpensive...whats the total cost you're looking at?

[jgarland79]

The parts look inexpensive...whats the total cost you're looking at?

I haven't added it up yet. I think it's about $15 / per meter (60 leds), $10 each for the step down power converters (I ordered 6). I think I can run about 500 lights per power converter. The most expensive part is the time. and I ordered a new laser cutter to use for this project. That was about $3500, but you can always use someone else's, that just costs you more time.

[jgarland79]

My latest drawing of the tail light seems to be just right. That curve on the outside is a bitch.

37484

[jgarland79]

http://www.ebay.com/itm/181849944119

I hooked up one of these to my active load last night and calibrated it to output 5V with a 5Amp draw. I couldn't do too much more because my bench power supply maxed out with 14V @ 2Amps which produced ~ 5V @ 5Amps from the buck converter. That's 89% efficiency. Right?

[Bitsyncmaster]

http://www.ebay.com/itm/181849944119

I hooked up one of these to my active load last night and calibrated it to output 5V with a 5Amp draw. I couldn't do too much more because my bench power supply maxed out with 14V @ 2Amps which produced ~ 5V @ 5Amps from the buck converter. That's 89% efficiency. Right?

Yes that looks correct. 28 watts input, 25 watts output.

Most switching regulators run around 90%. When the currents go higher you start seeing more losses with the wiring and circuit board trace voltage drop adding to the inefficiency. Also the switching may throw your amp and volt gauge readings off a little. You would need true RMS meters to get very accurate readings.

[Timebender]

This kind of reminds me of Mercedes new autonomous car with the LED matrix in the back that lets a car behind know that someone in front of you in crossing by using an animation of left to right or right to left vertical bars.