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led turn signal project?

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=73388
Printed Date: May 10, 2025 at 1:40 PM


Topic: led turn signal project?

Posted By: kiesta00
Subject: led turn signal project?
Date Posted: February 23, 2006 at 11:12 PM

I have a 98 honda prelude and was thinking of making some led turnsignals for the rear.  I still haven't come up with a complete design, just throwing some ideas around right now.  I want to have an array of leds 30 columns and 3 rows.  This is the tricky part...I want to make them blink (shift) to the left or right, depending on which turn signal is on.  If I put on the left turn signal, I want the rightmost leds to turn on and then make the rest of the leds turn on in a gradual shift to the left (like 1 second total per cycle with a break of .5 seconds in between).  I'm an EE major so i'm fairly familiar with technical stuff, I just don't know where to begin here.  Any ideas would be greatly appreciated.

Keith




Replies:

Posted By: KPierson
Date Posted: February 24, 2006 at 6:13 AM
The easiest way would be to use a programmable microcontroller.  A program like that would be very easy to write, and the associated hardware would be very simple.

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Kevin Pierson




Posted By: sibbles
Date Posted: February 24, 2006 at 9:08 AM
Hi

Isn´t this just what you need?

Counter

Just a thought

Regards
Sibbles




Posted By: rwamser
Date Posted: February 24, 2006 at 9:37 PM

I Have done somthing Simular in that I put 15 LED's in a "V" shape in my outside rear view mirrors and sequence the LED's inpairs ( except for the one at the point of the "V") .  I used a Microchip Flash Microcontroller 16F627A  thgat I programmed.  Since this Microcontroller only has 14 usable I/O( 18 Pin )   You would be better off using  a Microchip 18F452 which has 33 Pins of I/O  of which you could use 29 for your project ( 1 Pin Turn Signal Demand, 1 for Brake Demand, 1 for Master Reset , ans 1 for Clock Input )  Since the 18F452 does not have unought Output to drive all the LED's use Transistors to drive the LED's  What I have done is used the Car's 12 VDC supply with a 5VDC regulator for the 16F452 and a 3.3 VDC regulator for the LED's, the LED's I used are super Bright Red 70 Ma.  I turn them on in sequence for Turning and all on for Braking.  As for the Program the program runs a simple loop and when a turn or Brake demand is inputed the Program goes into a INTERRUPT routing with a timer controlling the sequence rate that is programmable ( I have set it at about 2 second for the turn sequence )

If you would like any more information you can contact me at

richard.wamser@sbcglobal.net





Posted By: KPierson
Date Posted: February 24, 2006 at 9:48 PM

When dealing with that many LEDs I would also suggest that you look in to a matrix configuration and multiplex the outputs.  You can use 12 output pins to control 36 different sets of lights (I'm assuming each column will be a set).  Should be able to complete the entire project with a 20 pin chip, as long as you use separate circuits for each side.  Atmel is supposed to be releasing a family of 20 pin chips this quarter.  The Atmel chips can drive LEDs directly (although probably not in this circumstance) and can be configured to use a fairly accurate onboard clock (reducing overall system components).  Keep us updated on your progress with this! 



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Kevin Pierson




Posted By: WILL85IROC
Date Posted: February 27, 2006 at 3:10 PM
sounds like a good idea but make sure its legal in your state...    the blinking is ok but your dont wanna get pulled over for trailing LED turn signals...

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" WILL85IROC "




Posted By: kiesta00
Date Posted: February 27, 2006 at 9:46 PM
thanks a lot for the help.  I'm pretty sure cops don't care around here about LED lights, they don't even know what they are lol.  Right now I have clear turn signals and they haven't pulled me over yet...I'll let you all know how the project goes.  Thanks again




Posted By: ff-mike
Date Posted: March 01, 2006 at 2:55 PM
I have it in my head, but hard to put into words, so bare with me....

First some givens-

  • The pulse from the flasher can be stretched for other uses, such as a cornering lamp

  • We have 2 outputs from the directional switch, to tell which lamp to turn on(l/r)

  • Cops have directional controllers which will sequence lights in an array to a direction- available under 40


We can use the constant-from-pulsed to turn on sequencer from either directional.
We can then use AND gates to take the which-directional and the sequencer output to direct the signals to the correct led array





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