How 2: Rear lights + brake lights?

[JoFreak]

Hi guys,
I'm trying to get some lights onto my Slash 4x4 but I'm having a few problems regarding the rear lights.
I want to use the same LEDs for the always-on rear lights and for the brakes.
Meaning they are dimmed all the time, and when I hit the brakes they are supposed to go to full brightness.

I found and read Brian's thread on using an old servo board and will do so.
But how do I manage that the brake lights turn to full brightness as soon as I hit the brakes and not just after I pushed the trigger at least quarter of the way?
And what do I need to do so that the lights stay on all the time, but visibly darker, when I'm not on the brakes?
Maybe with parallel circuits? One permanently on with a higher resistor and let the servo board switch the parallel circuit on, with a second resistor which, parallel to the first resistor, results in the lowest possible resistance for the used LED.
That should do the trick if can get the adequate resistors, shouldn't it?

I'm thankfull for any help you guys can give me.
I do have basic knowledge of ohm's law, how to calculate resistors and so on, but absolutely no idea on how this servo board works.

[marzac2]

Just FYI, this is a feature on some MGM ESC's. There is a plug on their ESC's that you can plug a couple of LEDs in to and they go full bright when you hit the brakes.

[Overdriven]

Tamiya has some LED controllers just for the purpose you're refferring to. They also do turn signals if desired. The easy thing to do would be 2 sets of LED's though. One set for "dim" that stays on all the time and one set for "bright" when the brakes are applied.

[bdebde]

Dimension Engineering DELight

[JoFreak]

Thank's to you all, but all of those solutions cost way more than what I am willing to pay for this little gag.
The dimension engineering solution costs ~60$, the Tamiya TLU-02 costs ~60€, and to ditch my perfectly fine MMP for a probably way more expensive MGM just for some lights is too much as well.

I think I do know what I'm going to do with the servo board.
Tomorrow, when my LEDs and resistors should arrive, I will do a quick soldering job to see if it works as I imagine.
I will post a wiring diagram if it does.

[Arct1k]

Axial NVS or I think RC4WD might have a cheaper solution

[BrianG]

It will be fairly simple to have the servo mod light up reverse and/or brake lights, but it will be missing logic to know when to light reverse or brake lights. As far as the receiver signal is concerned, the reverse and brake signals are the same; the ESC dictates whether to activate brakes or reverse. So, you can make the brake lights come on during braking, but they will also come on when in reverse. Likewise for reverse; they will come on during braking and reverse.

[JoFreak]

Ok, thank's Brian!
I have no problem with the brake lights coming on while reversing.
I hardly reverse while bashing
You think the idea with the parallel resistors could work?

[simplechamp]

When BrianG did his he used 2 equal value resistors, simulating the pot being centered, and from this he got the action at about 1/4 trigger pull (forward or reverse depending on your radio settings). If you played with the resistor values a bit you should be able to make it turn on with even less trigger pull (or more, but sounds like you want it to come on the instant you hit the brakes). Just make sure the total of the two resistors adds up to the resistance of the pot your are replacing and play around a bit. In effect you are using the two resistors to simulate a pot that is fixed at one position.

For example instead of using two 2.5k ohm resistors you could use a 4k ohm and a 1k ohm (won't be able to use these exact values, but you can get close). Both setups add up to 5k ohm to simulate the pot, but the equal setup will appear as centered, and the other setup will appear as moved further one way or the other. Again, just play around a bit and see what kind of response you can get.