Lume1-FW3X: Constant Current Buck-Boost & FET Driver with Anduril1/2 + RGB Aux

I went…

1. Red 220

2. Green 330

3. Blue 100

Better… by my eye…might lower Green even more… taped everything down with Kapton Tape Hot-Aired the microscopic resistors

This is what I was thinking too since blue seems very low as is.

I guess the real test is how does your yellow and cyan look?

[quote=iamlucky13]

Does that even help much? Those values just set PWM on the FET, they don’t magically lower the maximum current. So while the LEDs don’t get so bright that it’s obvious that they’re overdriven, they are still overdriven half of the time. I’m not exactly sure how this in turn affects LED life expectancy.
My understanding may be off here, because I really don’t get how limiting the FET should save the LEDs.

Lets move on from 219B. The prototype used it and people have been building them for years.

Stick with 3500mAh battery (like was already mentioned above) and assuming heat path and reflow are good, enjoy your CRI. If you think someone will stick their brand new uber vape batteries charged to 4.25V in your light you can ask for $9 LED deposit when you lend it out.

The 50% PWM firmware is just a hack and probably protects edge cases. The stock driver really had no other way besides disabling FET so people asked and that’s pretty much all you can do.

Do you mean Red 220?

When you say better, are they close enough, like the Emisar? How are your intermediate colours?

Yep 220…

Swap resistors:
red to green
green to blue
blue to red

New values:
Red 220
Green 330
Blue 100

Swapping the resistors is a test of patience. It’s not perfect but it’s way closer.

Close enough……or what…

First NovaTac/Lume 1 :open_mouth:

You took so long I had to do my own! :smiley:

It’s close enough IMO. So close in fact you have to wonder if this is how they intended it.

KB, now fix the flashing key. Cut those traces and cross some wires :innocent:

Yep… :+1: I have to agree… Lexel sent me a boat load of different micro resistors for these or his boards, I might mess around with the last driver, lowering the green and maybe the red a tiny bit more? Winter is coming… :smiley:

Hmmm……… I sure would like to get rid of this useless :rage: “MUGGLE MODE” :rage:

Another option with the provided resistors would be to use the 330Ω on the green, the 100Ω on the red and just solder bridge the blue. Would that fry the blue?

Hello everyone,

I'm glad some people have received their boards! Unfortunately I personally haven't yet received mine yet, though they are in the mail and I should receive them sometime today hopefully.. I see that there has been a good amount of feedback so far so here are my comments.


Yes the system should work with red LEDs. However, you should make sure that FET is disabled; this can be easily done by changing the config files (e.g. change the ramping tables) and reflashing the firmware so that the FET is never used. The system will run in buck-mode for the entire range if red LEDs are used.


Yes there is, please see my github for the latest versions. https://github.com/loneoceans/lume1-fw3x-anduril/


Thanks for the detailed feedback gokalpm. I'm glad you were able to get it working well in the end.
- I did not design the PCB with cutout because newer versions of the FW3x flashlights no longer have the notch, so I was told by Neal to make a round PCB. Filing would work to fit the older ones.
- The RGB aux board was designed for the Lumintop MCPCB not the Noctigon one

- The aux LED board should sit flush on top of the MCPCB. The Lume1 datasheet has an assembly section on how I put things together, and things to take note of as well.


That is a very clean build, thanks for sharing!



That's unfortunate to hear.. :( If you scroll back in this thread a while back when I got the first proto samples from Neal (the green PCBs), I found the resistors chosen to be non-ideal and made the Aux LEDs far too bright, and specifically requested them to be changed. I think Lumintop probably wanted really bright AUX lights, but that was not what I think they should be because I prefer the AUX LEDs to be very dim.

Personally, my recommended resistor values are:
1.8k for Red and Blue
5.6k for Green

These values allow for a good change in brightness when using the 'dim' AUX settings in Anduril as well (especially the breathing rainbow mode which I use most often), and they work really well in the nighttime, but will not be very visible in the daytime. These values are listed in the datasheet on Github too.


LED intensity is controlled by the resistors, so swapping wires from driver to aux board will not change the brightness, but will change the ordering instead.


No please do not use a solder bridge! I'll need to ask Neal why Lumintop didn't change the resistors to what I specified.


When I designed this board, it was immediately after I designed the Lume1 board, which I assemble and solder by hand. The actual driver board has smaller components so the LED pads seem easy in comparison, but you are right that normally this would be a challenging job because they're tightly spaced. [Update: it's done! https://oshpark.com/shared_projects/mtHUb4gp]

I quite like the bright aux that can be seen during the day. For night time, he dim setting is dim enough. I wish it was balanced though… I believe even with the swapping around of the resistors, the green is still brighter and the blue dimmer than the red. I think I may try 75Ω for the blue (since no resistor at all is a no go), 160Ω for the red and 330Ω for the green. I have ordered some 0402 resistors to try.

As someone who has never soldered anything before, it sounds like the aux lights are going to be out of the question, which is fine. Is just the driver swap fairly easy? What’s the process? Unsolder the wires from the mcpcb, remove the driver, unsolder the wires from the driver, solder the wires to the new driver, install the driver, solder the wires to the mcpcb?

Yes. As some others mentioned if you have a first batch FW3A with the dog eared driver slant you will need to re-create that “slant” in the new driver with sand paper or a file.

If you have a new batch FW3A with MCPCB screw you just need to check for any long burs coming from where that hole is tapped into driver cavity (honestly I forgot to even check mine).

Soldering to the driver itself is a piece of cake, the pads are large.

Soldering to the MCPCB is harder but as long as you have a clean, blunt tip and either A) some fresh leaded solder or B) flux paste you can probably do that too without much trouble.

I wouldn’t ordinarily re-use wires but in this case you could get away with it. They are good quality. Lumintop thermal paste is questionable but adequate. Those would be two “extra” things I always do because I have all the stuff for it already.

Wow, that is a good looking board :slight_smile: Nice work loneoceans!

I have a lot of soldering experience, and those RGB pads look great. My advice is to tin the pads and wires first while using plenty of flux. The connections should be a piece of cake at that point.

I have just casual experience during past 2 years and did it so it’s doable for sure.

It still requires working with 6 wires, 4 of which are very small, steady hands, good eyes or magnification, etc.

I think you take it for granted some if you are experienced with tools and probably young. Doesn’t mean it shouldn’t be made easier for DIY if its possible (and it was it seems cause the new revision seems better)