Scrolling LED Third Brake Light!

[Picklz]

Alright so a few of us are entertaining the idea of setting up the Third Brake light in the MS3 (which is an LED light) To scroll back and forth, or knightrider style. Right now we are in the planning stages, we have a couple options. One would be a completly custom controller and light setup. This would give us the greatest flexibility and controll, but would also require the most work in the form of programming a microcontroller to control the LED's as we see fit. Second option would be to find some type of LED controller or pre-made Lightbar that already has a controller in it, and modify it for our use.

Quick update:

At the moment for a first run we are looking at the following for features:
1) At least 1 scrolling / chasing pattern when you step on the brakes, needs to stop after 5-6 seconds and become solid.
2) If we go with more than 1 pattern, a button or switch will need to be used to switch patterns.
3) Ability to disable scrolling feature completly so the 3rd light works as a standard on / off light
4) Ability to turn on / off a feature to have the 3rd brake light scroll a pattern while the vehicle is shut off, at a lower brightness.

If there are multiple patterns some sort of indicator such as a row of LED's near the instrument cluster, or integration with the Radio LED's would be great, but I think we are going to leave that for an add-on type situation once we get the main part of the project working.

I found this which has some potential, but I'm open to ideas or suggestions
http://www.chromeglow.com/catalog.asp?prodid=543501&showprevnext=1

Here's and example of a fairly simple controler someone built, complete with code. It would need to be modified for our use a bit, and to support more LED's but it might be a starting point. Thanks to Jay for this link.
http://home.wanadoo.nl/electro1/avr/kitt.htm

I'm looking into PIC programming right now, if anyone has experience with that let me know.

Post #11 Has some basic LED and Electronics Info in it for those interested, if there's anything anyone would like added let me know. I'll be updating it over the next day or two.


Might as well post up the original inspiration for this thread (Colin actually showed it to me)

http://www.youtube.com/watch?v=K6sZg3iL5EY

[mazdamn02]

All I know is you'll need Jeff, the forum MacGyver.

[Picklz]

pffft I can manage this....I think...but yeah Jeff could probably whip that up in 30 seconds flat.

[Young Roids]

Reminds me of those add on led signs that scroll messages like the bank signs only ones for your car. I saw a dude in a blazer on Daytons with the message scrolling "I have no weapons and no drugs in the vehicle. Leave me alone." It gave me a laugh.

[dmention7]

Might as well post up the original inspiration for this thread (Colin actually showed it to me)

http://www.youtube.com/watch?v=K6sZg3iL5EY

[Young Roids]

That really works well with the eclipse rear light design how they go accross the whole rear of the car. BUt I wonder if the cops would give you touble with that setup.

[mndsm]

As long as you weren't doing stupid shit with it on the highway and letting it function as brakes/turn signals, I don't see how they could. It's definately within DOT guidelines for brightness and it is the right color, so unless you had it strobing or something like a cop car, they'd probably let you go.

[dmention7]

yeah, you'd probably want it to function more or less normally as a brake light, but it would be cool to have it doing the back and forth scan whenever the car was parked or something.

[Picklz]

I think as long as after 'x' seconds it goes to solid and isn't strobing real fast constantly they would leave you alone. Thats whats nice about the premade ones they are already set to go solid after 4-6 seconds usually. It would be nice to have an over-ride switch to turn the scrolling feature off if you wanted.

Hmm would you want the 3rd light to scroll back and forth with the car parked / off? Kind of like a security LED but on the back of the car?

[dmention7]

I dinno, but I think it would be kinda cool to be able to do that. It'd work best if it did it under maybe half voltage so that it was a bit dimmer.

[Picklz]

Alright so here is A little Electonics / LED Primer

As a couple people have asked for this information I figured I may as well post it up. If I miss anything that should be in here or something is unclear let me know and I'll do some editing :)

This is a Work in Progress, I'll be adding things over the next day or two.

LED - Light Emitting Diode

LED's are a semiconducter of sorts that emit light. Some of their advantages over standard incandesent lights are small size, long life, low power draw and brightness.

Your basic LED has two leads on it or 'legs', an Anode and a Cathode. In simpler terms the Anode is the + and the Cathode is the - as far as current is concerned. Usually one leg of the LED is longer than the other, this is the Anode or + side, also if you look at the LED from the top down, there should be a little flat spot (LED is not completely round) this should corrospond with the Cathode side (-) of the LED (incase the Legs are the same length).

Usually LED's run on anywhere from 2-5volts, some have built in resistors so you can hook them right up to 12 volts. If they don't then you need to put a resistor in-line to reduce the voltage going to the LED. Wherever you order your LED's from should have a data sheet available (or specs posted) that will list what voltage range the LED is capable of running in. Less voltage will equal a dimmer LED, too much and it'll burn out, start on fire, or 'pop' :)


-Resistors-

A Resistor is a electronics component that limits voltage, to figure out what resistor you need for an requires some math and the use of Ohms Law - Resistance = voltage / current....

The formula to figure out what resistor you need for an LED is:
Resistance = (Power Supply Voltage - LED Voltage Drop) / LED Current rating.

So in our case if we had an LED that required 2.0v (fairly common for standard red LED's), and a current rating of 15ma (again, pretty common), you would use the folloing formula:

(12-2)/.015 = ~666

Yeah so thats a creepy number but anyway that's saying you would need a 666ohm resistor or greater, resistors only come in certain values, and those are determined by color codes. The nearest ressitor to what we want would probably be a 680ohm 1/2w resistor. Keep in mind cars generally run in the 13-14v range not a solid 12, so that may need to be figured in when hooking up LED's to a vehicle.

Here is a handy resistance calculator for those afraid of math:
http://led.linear1.org/1led.wiz

[Picklz]

I agree Jay, that idea hadn't really crossed my mind. Might be better to get it working first then look at a circuit that will apply power to it when the vehicle is off, which shouldn't be all that hard to do.

[mndsm]

I dinno, but I think it would be kinda cool to be able to do that. It'd work best if it did it under maybe half voltage so that it was a bit dimmer.

Add to that, yeah LED's are low voltage, but my car sits a ton, so even something like that could drain the battery. Any way to have a switch to turn it on/off while parked so we have the option of just shutting it down?

[Picklz]

sure that would be easy enough to add in

[mndsm]

The cool part is there is a great little switch blank right by the steering column in which to put the setup for that. I'm liking this more and more. I think as we get closer to building one, we should come up with a final idea as to what exactly we want it to do, and then use whatever knowledge (or lack thereof in my case) to build it to that spec. We seem to have a LOT of different things we all want to see in this, and it could get complicated, QUICK.

[dmention7]

Maybe you guys could make a bit of ching selling completed units on the forums

[Picklz]

Alright so far were looking at the following for features:

1) At least 1 scrolling / chasing pattern when you step on the brakes, needs to stop after 5-6 seconds and become solid.

2) If we go with more than 1 pattern, a button or switch will need to be used to switch patterns.

3) Ability to disable scrolling feature completly so the 3rd light works as a standard on / off light

4) Ability to turn on / off a feature to have the 3rd brake light scroll a pattern while the vehicle is shut off, at a lower brightness.


As for #2, might be cool to have some sort of indicator as to what pattern is being displayed (if we go with something that offers more than one), but I dont know how feesable / easy that would be to do.

[dmention7]

What about a second, smaller display that you can locate on your dash like the guy with the eclipse did? It could mirror what the tails are doing

[Picklz]

hmmm thats possible, not sure where to mount it exactly though, what would be really cool would be to integrate it into the lights that are on the radio, that increase / decrease when you change the volume...but I don't think that's something I really want to tackle, at least not right away.

[mndsm]

Yeah I think the 3rd brake is the most important thing at the moment.

[dmention7]

C'mon..... go big or go home.

[mndsm]

Agreed, but one thing at a time. I have a hard enough time with anything do do with electricity, and electronics in general, and now you want to add this too?

[Picklz]

Yeah my thought is define a small number of features, the core stuff. Figure that out then we can expand from there.

Right now I'm seriously considering trying to learn PIC programming - looks like those little things can do all sorts of cool stuff. Looking for a decent programmer right now, going to have to see if one of the old PC's I have has a parallel / serial port on it or not, if not I'll have to get a USB version.

[dmention7]

If it's cheaper, matt, you could always get one of those little USB->Serial adapters. I think those only run about $15 or so.

Also, I think one of the core features should be the ability be integrated with your stereo so that your brake light pulses with the beat. That should be easy enough.

[Picklz]

Most of the PIC programmers I looked at say they dont work with the USB->Serial adapters, not sure why, but i'm 99% sure I've got a serial port on one of my machines at home.

I'm thinking of ordering this programmer (http://www.apogeekits.com/pic_programmer_vm111.htm) still doing some research though.

Good one about the light flashing to the beat of the music, maybe we could get some strobes in the headlights and some underbody neons too! :p

[mndsm]

Matt, if you need an old rig w/ a serial port, I have one. It likes to eat hard drives sometimes, but should serve your purpose. Also, my laptop may have one on it too, i'll have to look.

[Big Nate]

These are all very good ideas and Jay stop trying to add stuff to it.

I agree we need something working then we can add to that.

[Picklz]

Matt, if you need an old rig w/ a serial port, I have one. It likes to eat hard drives sometimes, but should serve your purpose. Also, my laptop may have one on it too, i'll have to look.

Thanks for the offer, I've got like 4-5 PC's at home, and I'm pretty sure one of em has a serial, just have to double check when I get home tonight. If not we can talk and maybe figure something out with a laptop or the spare box you have.

I think the fastest way to do this would be to buy one of those bike lights and modify it, but now you got me started so I think I may try and go completly custom :p reading about PIC programming right now.

First post has been updated a bit.

[Picklz]

Just found someone that posted some various projects they have done w/ a PIC (Programmable microcontroller).

The last one on this page looks like it could be adapted very well to our application, it already has different 'modes' programmed, as well as a scrolling 'column' feature which is pretty much what we are looking for. Also at the very bottom is a link to another project that has code for making patterns and such. I think with these code samples it wouldn't be all that hard to program something to our liking

http://www.ke4nyv.com/picprojects.htm

[dmention7]

Matt, I've always been kind of curious how all these programmable microcontrollers and stuff work, so if this project does get rolling, I'd like to meet up and actually see the process in action.

[Picklz]

Same here Jay, I'm sure we can meet up once I have some idea of WTF I'm doing, reading a few tutorials now as I have time, and I'm going to look through those exampes in a bit to see if I can figure out what is going on.

[mndsm]

Yeah, I want to be in on this as well.

[Big Nate]

like I said guys lets just do a mini (not the car) meet. we can look at all the different things we can do with these leds and how hard it will be to do them.

[mndsm]

Yeah, we should get that together.

[Picklz]

I would be up for that, not that we can't put our ideas in here but meeting up is cool too. I'm pretty busy the rest of this week, maybe this weekend though?

I'm trying to figure out how man LED's we'll need to have total, 2 rows of 10 or 12? Maybe more? That'll effect what Microcontroller we have to use.

I found a couple other programmers (one is USB) but I have to figure out what chip I'm looking to use before I order one.


Edit: I should clarify that, we need to decide how many 'channels' we need to be able to light up individually, for example if we had two rows of 20 LED's (40 total) and the top and bottom LED in each column was connected, so that when column 1 lights up, both the top and the bottom light up at the same time, that would only be 20 channels to control, but if we wanted each LED to be controlled individually that would take 40 channels, makes sense?

[spek1098]

Well if you are in need of an electrical engineer, I have a retired one sitting at home who is always asking me for projects to do. This would be a sinch for him. All he would need is what options you'd want the lights to do, how you want to control it and how you want to know what setting it's on, and I'm guessing he could have a design within a week. Let me know.

[Picklz]

As much as I kind of want to play around with the PIC's if he'd be willing to help out that would be pretty cool.

I guess the first thing we really need to figure out is how many / what size LED's this is going to take and exactly what pattern(s) we want?

[mndsm]

Well, I think the thing is there to make the determination of what will fit to maximise output/flexibility. if I could do 2X2 (4 rows 2 to each channel) that would be ideal, but I am not sure about the space constraints on the car. Mebbe I do what I said yesterday and go take it apart.

[Picklz]

Yep gonna have to pull it apart and see what will fit, I have a feeling more than 2 rows may not fit, I'll have to see if they make 3mm ultrabright red LED's, that'd allow for some more wiggle room than the 5mm versions.

[mndsm]

Well, if the 5mm ones are bright enough, and we do two single rows, that ought to be enough.

[Picklz]

Yeah, I'm guessing 15 - 20 LED's across x 2 rows...would be really cool to set it up to individually control each LED, could have some pretty cool patterns, but even just each column being individual and the rows tied together would be alright.

[mndsm]

We could come up with some silly ideas for programs if we could control 40 LED's individually.

[AJ]

I'm all giddy, I want! lol

[Picklz]

I Just ordered a PIC programmer :eek: :D

[mndsm]

Heh, this seems to be garnering some real interest. I'm glad I decided I wanted one.

[Picklz]

Alright here's where I'm at, I ordered a PIC programmer as stated above, this weekend I'm going to see about taking the 3rd light apart to see how much room we have to work with, then try and make a decision as to what LED's to use and how many.

At that point I'm going to pickup / order all the parts to build a prototype. I also have to learn how to Program a PIC so this could take a while, but I want to do it for the hell of it.

If / when I manage to get something working that ya'll like I'd be happy to share the program / schematic and program the Microcontrollers - maybe even build a few, however it may be faster to see about spek1098 having a talk with his EE to prototype it out.

[StealthSpeed3]

i think i want in on this carnage as well. i like the "scrolling" idea, plus on a black car would be a small nod to K.I.T.T.

[Picklz]

So it looks like the OEM 3rd brake light is around $100 from tonkinparts, definitely more than I was expecting it to run, was hoping to get a spare to modify but not sure I want to spend that kinda cash.

Working on a shopping list for parts to get a test circuit together right now though.

[dmention7]

Ouch yeah, $100 is a lot to spend unless there is a solid plan in place for using it. Hopefully we can get most of the hard stuff done without needing one.

[Picklz]

Alright some more info for this project.

This is a work-log for a custom built from scratch arcylic PC case, its application here is the tools and techniques used in working with the acrylic, which may come in handy if we decide to make our own lense's:

Third post down on this page shows some bending techniques, the whole thread is pretty impressive to see what can be done with some relativly inexpensive tools.
http://forums.bit-tech.net/showthread.php?t=134263&page=3

Sources for Acrylic/Lexan/Plexiglass -
http://www.tapplastics.com/shop/category.php?bid=24&PHPSESSID=20080114112028161260 8532
http://www.professionalplastics.com/cgi-bin/main/co_disp/displ/prrfnbr/85460/sesent/00/Lexan%C2%AE-9034-Polycarbonate-Sheet

[Picklz]

Mini Update:

I haven't forgot about this, things are insane at work right now and I just haven't had time to spend working on this at all. Ive got the parts to prototype something, and Just got the programmer. So hopefully I'll have some free time soon to work on this some more.

If anyone else feels they want to take a stab at this in the mean time I'll be happy to loan the programmer out and such otherwise I'll update again when I've made some progress.

[mazdamn02]

mebbe this can help: http://gizmodo.com/357181/how-to-make-the-new-knight-rider-led-scanner

[Z-licious]

One of my majors was computer engineering and programmable microcontrollers was one of my favorite classes. I still remember some stuff, maybe I can answer some of your questions.

[mazdamn02]

One of my majors was computer engineering and programmable microcontrollers was one of my favorite classes. I still remember some stuff, maybe I can answer some of your questions.

Can you whip me up an ecu-controller for my speed3? That'd be niiice.

[Z-licious]

Can you whip me up an ecu-controller for my speed3? That'd be niiice.

no

[dmention7]

That's a mexicant for ya.....

[Picklz]

Alright I got my other PC up and running and got the programmer hooked up to it, so I'm makin some progress, hopefully this week I'll get a chance to try my hand at a sample program of some sort, I still have to order a couple things to assemble a test circuit (couple of the parts were the wrong model).

[96HawkCnvt]

Alright I got my other PC up and running and got the programmer hooked up to it, so I'm makin some progress, hopefully this week I'll get a chance to try my hand at a sample program of some sort, I still have to order a couple things to assemble a test circuit (couple of the parts were the wrong model).

FYI, my day job is in electronic components & I have a lot of connections. Let me know if you need any samples (free of course) or anything and I'll do my best to help out.

Todd