[VirtualGuitars]

Originally Posted by hugo_nz

From what I understand from the technical docs all ambient lights are connected in series and addressed in the BCP. This is so the BCP can log exactly which light goes out in the event of a failure. When I was looking into the RGB modules I found that each one of them has a tiny controller to take care of the addressing with the BCP. You can check the difference by taking one of the footwell lights out and comparing the circuit board.

What doesn’t make sense is that those lights have 2 LIN wires whereas the door lights do no.

It’s a mystery.

Those damn Germans! 😂😂😂

[Paladin1]

Ausgezeichnet!

[sor]

There must be an intermediate module interfacing with that?

[hugo_nz]

Originally Posted by sor

There must be an intermediate module interfacing with that?

Already mentioned in an earlier post.

[sor]

Originally Posted by hugo_nz

Already mentioned in an earlier post.

Sorry I don’t know what a BCP is or if this is also the door control module or how they relate.

What I glean from the last post with the documentation it seems clear that these lights don’t connect to anything but the door control module and probably aren’t directly related to ambient lighting bus at all.

The door control module probably doesn’t use any logic or communication/addressing to control these lights, the “PWM signal” is likely just a standard LED PWM driver that is powered when on and not powered when off. The translation makes it sound like there is some special pulse sent to tell the light to turn on, but is probably just normal LED PWM power.

[sor]

Looks like the door light is driven by a 200hz PWM signal. It doesn’t look like it immediately because it has a 100% duty cycle (full on DC), but I caught it as it was dimming to “off” and you can see the duty cycle ramp to zero.

The language of the doc about “sending a signal” had me thinking this was something more than just a standard PWM, but it isn’t. Now can’t wait to get my hands on the projectors to see what is so different about them.

View post on imgur.com

[hugo_nz]

Originally Posted by sor

Sorry I don’t know what a BCP is or if this is also the door control module or how they relate.

What I glean from the last post with the documentation it seems clear that these lights don’t connect to anything but the door control module and probably aren’t directly related to ambient lighting bus at all.

The door control module probably doesn’t use any logic or communication/addressing to control these lights, the “PWM signal” is likely just a standard LED PWM driver that is powered when on and not powered when off. The translation makes it sound like there is some special pulse sent to tell the light to turn on, but is probably just normal LED PWM power.

BCP is the master control unit (basis central platform). All other modules communicate with it, and it serves as the network hub. Door ambient lighting is interesting because the colour signals come from BCP but power comes from the individual door modules.

[evanevery]

I ran up a test to compare the puddle "lamps" with the puddle "projectors"...

1. My vehicle is sending 14.1v to the circuit when illuminated. This is fairly normal voltage for a standard auto "12v" battery circuit.

2. On my bench, with my power supply dialed to 14.1V, the factory puddle "lamps" draw 55ma.

3. On my bench, with my power supply dialed to 14.1V, the puddle "projectors" draw 154ma.

The puddle projectors draw almost 3 times the current that the puddle lamps do.

As originally theorized, It's pretty likely that the circuit is just shutting itself down (tripping) to prevent over-current. We are actually lucky that nothing appears to get permanently fried...


NOT COMPATIBLE!

[sor]

Originally Posted by evanevery

I ran up a test to compare the puddle "lamps" with the puddle "projectors"...

1. My vehicle is sending 14.1v to the circuit when illuminated. This is fairly normal voltage for a standard auto "12v" battery circuit.

2. On my bench, with my power supply dialed to 14.1V, the factory puddle "lamps" draw 55ma.

3. On my bench, with my power supply dialed to 14.1V, the puddle "projectors" draw 154ma.

The puddle projectors draw almost 3 times the current that the puddle lamps do.

As originally theorized, It's pretty likely that the circuit is just shutting itself down (tripping) to prevent over-current. We are actually lucky that nothing appears to get permanently fried...


NOT COMPATIBLE!

Now the question is whether it can be made to work

[evanevery]

Originally Posted by sor

Now the question is whether it can be made to work

Its likely that the control circuit simply can't handle the additional power requirements. Whether this is due to some sort of protection or simply that the electronic components just overload/overheat and fail to function properly. (Thankfully, it doesn't appear to have "blown" anything, but I'm also NOT going to keep trying to use/test these...)

Sure, you could make it work by using a Solid State Relay (SSR) like a KF0602D. All you would need to do is locate the "full power" (12V) feed in the door panel and use the existing door lamp circuit for ground and switching...

Its likely, in order for this to actually work "right out of the box", that BMW will have to re-engineer the logic control board in the door. I fully expect the reason that this was an original build option, and then mysteriously cancelled, that someone at the factory had an "uh, oh!" moment when originally installing these on the production line...

As an EV, electrical management and usage on our vehicles is likely much more highly scrutinized and engineered. It is quite possible that the control board was simply designed as efficiently as possible and no one considered the use of the optional, higher-power, puddle projectors.

As for me, I'm not hacking anything electrical in my vehicle just to get some puddle lamps working. Its just not that important...

I will however, give the projectors back to my dealer and maintain my "WeOwe" for the option just in case BMW modifies something to make this possible...

[sor]

Since we confirmed it is being driven by PWM, some programming could possibly adjust the duty cycle from 100% to something slightly lower, which could resolve the issue. Of course the car would need to support that sort of thing which is unlikely.

I suspect maybe the ambient package leaves less current available for the puddle lamps, or just includes a less powerful driver for some reason, hence the call out of not being compatible with the ambient light package.

Waiting for mine to experiment with… will open them up if I can and see what we are dealing with. I agree that most people don’t want to hack their cars but I am just curious about the exact why and how. It’s an obsession. At least it’s not dangerous like tinkering with my 400v DC solar installation was

[sor]

Got the projectors today. They snap apart and I took a look inside. They are much more complex than the stock lights.

Specifically the part here outlined in red is a constant current LED driver, driving the higher powered light. I found the data sheet and looked at the reference diagram. The object boxed in yellow is a resistor that controls the amount of current driving the LED, 200mOhm. I swapped this resistor out with one that would set the current lower, though I only had one that would drop it to about 17mA draw, so as you can imagine it is dimmer than it’s supposed to be.

I have more surface mount resistors of a variety of values on order and will play with it a bit more to see how it looks with more current but not too much to cause it not to turn on. I’m thinking about 4x the current it has now would be a good middle ground.

[Kayanarka]

Originally Posted by sor

Got the projectors today. They snap apart and I took a look inside. They are much more complex than the stock lights.

Specifically the part here outlined in red is a constant current LED driver, driving the higher powered light. I found the data sheet and looked at the reference diagram. The object boxed in yellow is a resistor that controls the amount of current driving the LED, 200mOhm. I swapped this resistor out with one that would set the current lower, though I only had one that would drop it to about 17mA draw, so as you can imagine it is dimmer than it’s supposed to be.

I have more surface mount resistors of a variety of values on order and will play with it a bit more to see how it looks with more current but not too much to cause it not to turn on. I’m thinking about 4x the current it has now would be a good middle ground.

I would like to buy a set of modified puddle projector lights from you, or would like to know what resistor works best 😉

[sor]

Originally Posted by Kayanarka

I would like to buy a set of modified puddle projector lights from you, or would like to know what resistor works best 😉

Went down the rabbit hole on this one. It was driving me crazy!

I noticed that even the modification to reduce current didn’t do the trick completely. It would only come on maybe 1/2 the time.

I ordered some wiring harnesses that match the car, and with some experimenting I found that it is not a current draw issue. The car’s driver will happily power two of the stock simple lights at the same time. I also cobbled together a simple circuit with a high power LED and simple resistive circuit and the car powered that no problem.

There is a fair amount of extra stuff going on with this circuit board in the projector. A microcontroller and perhaps a regulator in addition to the constant current LED driver. I decided to craft my own constant current driver board in order to eliminate anything I didn’t understand about the projector board and what its microcontroller was doing. Alas, my custom board did the same thing, flashes on a few times then shuts off.

I began to suspect the PWM power from the car was incompatible with the capacitance of the projector board, even though it runs mostly at 100% duty cycle. If I simulate a PWM at 200hz driving a capacitive load similar to the board, I get upwards of 1.2A spikes on the initial leading edge of the PWM! This is the capacitor charging up which happens in the blink of an eye but still significant and probably tripping the output protection.

In the end the solution was simple and I’m testing it right now with an unmodified projector. It’s to add a small resistor in-line such that the charging of the capacitance is controlled and slowed somewhat. Testing a 4.7 ohm 1/4 watt, but a 10 ohm 1/2 watt would probably work fine as well and be more effective at limiting inrush current. The nice thing is this doesn’t affect brightness at all, since the projector LED driver is constant current it will light up the same as long as the projector is fed a minimum of 6 volts.

I have a few of these harnesses so I can make a limited number of them with the resistor built in if anyone wants to try this solution.

Photos are of powering two normal lights at once, my custom version that didn’t help, the wiring harness with resistor spliced in, and simulation of inrush current given 10uF capacitance.

[VirtualGuitars]

Originally Posted by sor

Went down the rabbit hole on this one. It was driving me crazy!

I noticed that even the modification to reduce current didn’t do the trick completely. It would only come on maybe 1/2 the time.

I ordered some wiring harnesses that match the car, and with some experimenting I found that it is not a current draw issue. The car’s driver will happily power two of the stock simple lights at the same time. I also cobbled together a simple circuit with a high power LED and simple resistive circuit and the car powered that no problem.

There is a fair amount of extra stuff going on with this circuit board in the projector. A microcontroller and perhaps a regulator in addition to the constant current LED driver. I decided to craft my own constant current driver board in order to eliminate anything I didn’t understand about the projector board and what its microcontroller was doing. Alas, my custom board did the same thing, flashes on a few times then shuts off.

I began to suspect the PWM power from the car was incompatible with the capacitance of the projector board, even though it runs mostly at 100% duty cycle. If I simulate a PWM at 200hz driving a capacitive load similar to the board, I get upwards of 1.2A spikes on the initial leading edge of the PWM! This is the capacitor charging up which happens in the blink of an eye but still significant and probably tripping the output protection.

In the end the solution was simple and I’m testing it right now with an unmodified projector. It’s to add a small resistor in-line such that the charging of the capacitance is [...]

Sign me up! I will gladly buy a pair!

[sor]

Four pair of harnesses bench tested and ready to ship. $20/set plus send me a shipping label. PM me.

[hugo_nz]

Originally Posted by sor

Went down the rabbit hole on this one. It was driving me crazy!

I noticed that even the modification to reduce current didn’t do the trick completely. It would only come on maybe 1/2 the time.

I ordered some wiring harnesses that match the car, and with some experimenting I found that it is not a current draw issue. The car’s driver will happily power two of the stock simple lights at the same time. I also cobbled together a simple circuit with a high power LED and simple resistive circuit and the car powered that no problem.

There is a fair amount of extra stuff going on with this circuit board in the projector. A microcontroller and perhaps a regulator in addition to the constant current LED driver. I decided to craft my own constant current driver board in order to eliminate anything I didn’t understand about the projector board and what its microcontroller was doing. Alas, my custom board did the same thing, flashes on a few times then shuts off.

I began to suspect the PWM power from the car was incompatible with the capacitance of the projector board, even though it runs mostly at 100% duty cycle. If I simulate a PWM at 200hz driving a capacitive load similar to the board, I get upwards of 1.2A spikes on the initial leading edge of the PWM! This is the capacitor charging up which happens in the blink of an eye but still significant and probably tripping the output protection.

In the end the solution was simple and I’m testing it right now with an unmodified projector. It’s to add a small resistor in-line such that the charging of the capacitance is controlled and slowed somewhat. Testing a 4.7 ohm 1/4 watt, but a 10 ohm 1/2 watt would probably work fine as well and be more effective at limiting inrush current. The nice thing is this doesn’t affect brightness at all, since the projector LED driver is constant current it will light up the same as long as the projector is fed a minimum of 6 volts.

I have a few of these harnesses so I can make a limited number of them with the resistor built in if anyone wants to try this solution.

Photos are of powering two normal lights at once, my custom version that didn’t help, the wiring harness with resistor spliced in, and simulation of inrush current given 10uF capacitance.

You got me thinking about a project I abandoned a while back. I bought a sunroof ambient light kit (2 long thing LED strips meant to light up the sides of the sunroof) and while they work with the the x5/x7 they fail to light up with IX. They flash for the briefest second, and then nothing. I am going to try adding a resistor to the mix and see if that solves the problem.

[sor]

Originally Posted by hugo_nz

You got me thinking about a project I abandoned a while back. I bought a sunroof ambient light kit (2 long thing LED strips meant to light up the sides of the sunroof) and while they work with the the x5/x7 they fail to light up with IX. They flash for the briefest second, and then nothing. I am going to try adding a resistor to the mix and see if that solves the problem.

Is there capacitance involved in the driver? And what power source are you linking up to?

[hugo_nz]

Originally Posted by sor

Is there capacitance involved in the driver? And what power source are you linking up to?

It's intended to hook up to the footwell RGB light on the LIN bus. The kit I purchased allows the light colour to be the same as currently set in iDrive.

[VirtualGuitars]

Originally Posted by hugo_nz

It's intended to hook up to the footwell RGB light on the LIN bus. The kit I purchased allows the light colour to be the same as currently set in iDrive.

Oh, I like that!

[sor]

Yeah that one is tricky because there’s definitely a significant amount of power involved. An inrush protection resistor will probably need to have larger power rating, you’ll want to figure out how much current your light draws.

There are other ways to limit inrush current like an inductor but for the puddle lights the sizing is impractical.

You could try the same troubleshooting I did - figure out the power requirement for your strip, mock up a simple resistive load and see if that works or has the same issue. That will tell you if the power is available. Once you know if the power is there then you can move forward to determine if current limiting will help in your case.

[sor]

Three pair left.