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Modify the BMW Turn Signal Module to work with LEDs

Discussion in 'The Garage' started by Poolside, Apr 2, 2007.

  1. Poolside

    Poolside Syndicated

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    <BR>You know the problem. Well at least the small number of riders who made their own LED arrays for the turn signals for sure know the problem. You install the LEDs and the turn signals 'flash quickly' as if the original tungsten filament bulb is burned out.


    JJ and I have been collaborating on this modification and I think he's come up with a workable solution for most.

    JJ did ALL the testing and work for this procedure. Give it up everyone :clap

    I'm working on a few pictures to post up. And JJ will prolly send over a few as well.

    Skills needed:
    - Basic surface mount pcb soldering skills would be ideal, but anyone with at least small pcb component soldering practice can probably do this.

    Tools needed:
    - Temp controlled soldering iron. The most basic model with a temp dial is good enough.
    - Small pointed conical soldering tip. Or a conical with a 1/64" flat will be ok too.
    - Dremel tool or similar with a 1/16" or smaller carbide or high speed steel (HSS) cutting tip. HSS is more than fine. Only a single pcb trace is cut.
    - Something to hold the circuit board while soldering. A hobby vice or a pcb holder if you have one.

    Parts needed:
    - 2 common value 1/8W resistors. 1/4W will work but much more difficult to use. Not surface mount. The leaded parts.
    - Silicone adhesive applied with a toothpick. Or maybe hot glue, but the toothpick applicator is much easier.


    I'm sure I missed a few things here JJ. Check that, I know I did. You are the test pilot on this mission, what other or else did you use over there?

    This little project isn't quite finished. JJ is thinking about some simpler ways to modify the pcb. So we'll hash it over for a while.

    - Jim<BR><BR>
    #1
  2. Poolside

    Poolside Syndicated

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    <BR>Here's what's inside the controller. Very complex compared to the basic task it performs.

    [​IMG]

    [​IMG]

    [​IMG]<BR><BR>
    #2
  3. word1

    word1 I'm working on it...

    Joined:
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    :lurk

    I looked inside the TS controller when I replaced mine with a Kissan auto-cancel unit. For a second, I thought I had pulled the wrong device as it looked way too complex for the task at hand. :lol3

    _jay
    #3
  4. Poolside

    Poolside Syndicated

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    <BR>JJ started out with some testing. This trace caries the voltage level signal from an op amp, and represents the turn signal bulb current draw. The voltage is ''read' by an analog-to-digital converter in the microcontroller.

    [​IMG]

    [​IMG]

    If both incandescent bulbs are working, then the controller flashes the turn signals at the normal rate.

    If one bulb is burned out, the controller flashes remaining bulb quickly as a visual indicator to the rider that a bulb is out.

    JJ has the results and voltage measurements of more than a few tests.

    - Jim<BR><BR>
    #4
  5. johnjen

    johnjen Now, even more NOW!…

    Joined:
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    While I played the role of Dr. Science's, 'Jimmy' (here Jimmy hold these 2 wires) PoolMan was the brains of this experiment. I did collect the evidence that lead to the 2 possible solutions that can be used to overcome the circuits limitations.

    My flasher unit was modified to expore and discover what the circuit would do when forced into alternative modes of operation.

    That is a 5K 10 turn pot and a 4.7K resistor. The pot is connected from 5V to ground and the wiper feeds the fixed resistor which then connects to the microController. With this setup I can feed any voltage into the microController, simulate any lamp load and watch the circuit behave.

    JJ

    Attached Files:

    #5
  6. johnjen

    johnjen Now, even more NOW!…

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    So can we see a show of hands of those who would even want to modify their turn signal relay? I mean the doing of this is relatively easy, the hard part is having the experience and tools to implement the mod. Which leads back to my first question, how many are interested in this mod in the first place.

    Now that doesn't mean we won't finish telling our little tale of science and daring do, but I know at least 2 of us are interested in knowing who is considering doing this mod.


    JJ
    #6
    phreakingeek likes this.
  7. Poolside

    Poolside Syndicated

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    <BR>Hey JJ, people may think that big 'oil can' potentiometer is part of the modification. Freaked me out when I saw it :eek1

    The picture JJ posted was only a test setup. A proof design. The 'oil can' and the 'flying resistors' are not part of the mod.

    The modification requires two 1/8W resistors and a steady soldering hand. An eighth-watt resistor is about the size of a match head.<BR><BR>
    #7
  8. johnjen

    johnjen Now, even more NOW!…

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    Yeah what he said&#8230;

    It's just a test setup for exploring the circuit. The actual mod is real simple. In fact I'm thinking a single resistor will be just peachy.

    JJ
    #8
  9. Anorak

    Anorak Woolf Barnato Supporter

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    Brilliant idear gentlemen. I think you should leave the big variable resistor in the final design so the flashing rate can be altered on the fly.

    I see a market for an exchange service on these. If either of you have kids, there is your workforce. Steady hands and sharp eyes you know.
    #9
  10. Poolside

    Poolside Syndicated

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    Oh, nice. You'll have to clue me/us in on that.
    #10
  11. Poolside

    Poolside Syndicated

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    <BR>
    I'm sure Johnny Rocket's got something worked out.<BR><BR>
    #11
  12. johnjen

    johnjen Now, even more NOW!…

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    Yeah its called a big magnifying glass with lights. And I have loops and other visual aids... Really the hardest part is cutting the trace.

    JJ
    #12
  13. Suppermotodd

    Suppermotodd Tag Thief

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    Snobnal Mountain, TN
    :ear :lurk
    #13
  14. johnjen

    johnjen Now, even more NOW!…

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    Ok so that makes one of you so far that has expressed an interest in this mod. This picture is of the relay circuit board under test. We figure the circuit needs a certain amount of current draw in order to function. Thus far we are figuring a minimum of about 450mA per LED array (lamp substitute) of current is needed by the circuit. That is roughly 1/4 the current of a standard 1157/1156 bulb (about 2 amps).

    JJ

    Attached Files:

    #14
  15. autogiro

    autogiro Been here awhile

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    johnjen,
    If your 11xx friends don't come out of the woodwork I'll bet you would make a LOT of 12GS riders happy if you could figure out how to make our Brake! LED tail lights work like they used to, before the ZFE firmware update. The part that makes the tail light burn both filaments in the stock incandescent bulb as a running light then, as the brakes are applied, increasing the brake light filament intensity. Totally screwed up how the LED module functions! I'd also bet you could make a buck or two in the process.
    Auto:ear
    #15
  16. johnjen

    johnjen Now, even more NOW!…

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    Not having seen one of those Brake! units I'd be only guessing if we could get anywhere with one or not. It is a nice thought that we could figure out a work around to all of the difficulty that folks are having with them. But it also is a much more complex interaction between systems than this little project. Here we have a circuit that is accessible and easily lends itself to 'tweaking'. Perhaps when we are finished with this one we will want another project. :evil

    JJ
    #16
  17. autogiro

    autogiro Been here awhile

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    Well compared to the BMW turn signal module you modified, this one appears pedestrian in comparison. Double side daughter board but no components on the reverse. J2 and J3 connect to the ABS and timer jumpers on the front of the main board. I have some ideas but no expertise in implementing them. (one is to increase the voltage threshold at which the brake light circuit is triggered) Keep in mind I am no electronics whiz.:D
    Auto
    [​IMG]
    #17
  18. johnjen

    johnjen Now, even more NOW!…

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    Well that's 1/2 of the equation, the easy half. The biggest hurdle is gunna be the software/CanBus side of things.

    JJ
    #18
  19. Poolside

    Poolside Syndicated

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    <BR>
    Well there's your problem right there. It's Rev 1.0

    - Jim<BR><BR>
    #19
  20. Poolside

    Poolside Syndicated

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    <BR>
    I wasn't thinking of modifying the brake! LED board. But instead making something to interface with the bike.

    - Jim<BR><BR>
    #20