Sounds difficult, what functionality are you after ?
Running emitters like quad e21a in 3V or boost HX or even something like a triple 219B, HL2X or Osram white flats. Anything with a turbo amperage more than 5A but not compatible with DD due to very low Vf or otherwise intolerant to overdriving.
For higher current with low Vf LEDs then a 6~8A buck would be preferable, with the low switch limit of this buck-boost IC it barely even boosts anyway. For multi emitters like quad E21A the better option is to wire them in 2S2P and use a boost driver.
I agree on the boost portion of this driver being mostly unnecessary, but I still like that its there. I love that it can drive a UV and Red emitter efficiently. Flexibility in a BLF driver is admirable IMO.
6-8A buck is something I really want to see soon. Convoy and Sofirn has done it, but lack open source FW.
I agree on the boost config for the e21a quads. It makes even more sense when you consider the mcpcb wiring layout for 3V vs 6V. I overall prefer the Lume X1 for my desired applications, but since this one exists for sale already (and specifically for the FW3A), I was tempted to make it work.
I still think that it could make sense to have the 3A buck/boost and then programmable current (a la l4p) linear FET would be the ultimate flex driver. Energy efficient on sustained modes, cost efficient on crazy modes, and suits almost any emitter setup I can think of.
It would require quite a bit of hacking, although maybe not impossible. Here are the issues I can see:
The output of the op-amp needs to be fed into the gate of the FET, maybe doable with soldering of very small wires. You will need to remove the charge pump IC.
The PWM output from the MCU (probably) goes through a voltage divider before the RC filter. This voltage divider divides PWM voltage down to a level that will match measured voltage of sense resistor. This divider is probably optimized so that max PWM (255) equals highest desired output of the switching converter. You would probably need to mess about a little with those resistor values so max PWM equals max current you wish to obtain through the FET. You will loose some resolution of the switch converter but I take it that would be acceptable.
The FET chosen might not be very good choice for linear operation, you have to check that, possibly you’d need to replace it. Note that it’s a dual FET, not a “normal” single FET. It’s dual to prevent boosted current leaking back into the battery when voltage is higher on output side.
And as you probably know already, the software will need to be modified quite a bit.
Edit: The biggest issue is that the FET has to be turned off when using the switching converter. If you feed the output of the op-amp to the FET as well as feedback on the switching converter, you will need to find a way to isolate the op-amp output from FET gate when not using the FET.
Did you request permission from loneoceans to create this driver or is this another copy like what you did with the Tamagotchi driver especially since you’re now putting your own name (‘QuadBLF’) on the driver to make it seem like it is yours again? If you received permission, there is no problem at all and good effort.
I have several resonable questions. lume1 is the open source hardware or only open source firmware at all? Do we need to have special permissions if anyone want to make a copy of lume1 driver if we use original name or if we made some modifications of it?
From post 17 of loneoceans
Closed hardware? Like locked in safe? Schematics is not a hardware, its just instruction how to create a hardware. So thanks to smart guy Loneoceans i learned how to create a specific hardware. The PCB design is mine, i have source code and i can call it as i wish. It would be not nice to use Lume brand as your own, right? This will be just another driver inspired by Lume1, based on TPS63020 controller and open source software.
Open-source hardware (OSH). Lume1 is shared on OSH Park. Any questions? 
Any form of reference to loneoceans would go a long way in this situation. I’m not remotely an expert on the technical in-ands-outs of open source practices, but there are basic intuitive things that I’m sure many people feel on the topic regarding giving credit. I know if you want to get technical or philosophical you can justify anything. I don’t think you are entirely in the wrong for taking an openly shared design, doing value added work with it, then again sharing it openly in the same thread. But at least a small-font shout-out to loneoceans would really be appreciated by many here, including him I’d bet.
One thing I want to throw out there is that using poor tact and creating silly controversy here can be something to leave a bad taste in peoples mouths. I would hate to lose contributing member’s participation over anything like this. I hope the timing of LO’s silence in this thread is just a coincidence.
A few days ago after a hard work, i mount lume1 and rGb on FW3A…
nice…very nice…very efficient driver instead the original.
I put Cree Xpl 3000 90+ CRI and I am in love…
I have a question for turbo… why goes down so quickly? Seconds…
I have Anduril 1…any suggestion?
Have you set your temp limits/settings first?
I had the same issue with the lume1 driver I installed in my LM10 months ago. When I turned the light on in turbo I got a sharp stepdown 3-6 seconds after turn on, even with a cold light and fully-charged cell.
I asked about it in the lume 1 thread and was told this was expected behavior. The driver was optimized for maximum efficiency in intermediate modes and not turbo.
This disappointed me, because turbo mode was unusable. And based on how I mostly used my FW series lights, that meant the lume 1 driver was actually worse than the stock FW3A driver.
Perhaps the issue was fixed in the updated lume x1 driver, which I understand also fixed the lack of reverse polarity protection. I haven’t checked.
FW3A driver PWMs the FET in order to produce many “levels” of output between 7135x7 and full-FET.
Lume1 does not PWM the FET, so there are no intermediate levels between full regulated (3A) and turbo.
So when you are using turbo and the temperature exceeds the limit, it makes a big jump down.
This is the correct answer. The standard FW3A also immediately starts dropping but due to PWM you dont notice it right away. You can raise the temp limit a little or try a bit lower drain battery but nothing will get more out of such a thin/light host.
The driver excels best at medium modes up to 3A where you will get a longer runtime by comparison.
I’m not quite sure that’s really what’s happening.
A light with a large copper star in a thick chunky LM10 titanium host should not step down due to heat after just 3 seconds of turbo. I doubt if that’s enough time to even make the temp sensor in the driver lukewarm.
… yet that’s exactly what happened with the Lume 1 in my experience. I was not impressed.
Also note:
- attempting to trick the driver by setting the thermal calibration so it thinks high heat is actually room temperature made absolutely no difference. It still suffered a massive stepdown after a few seconds of operation.
- Same for whether the light was turned on with the head already hot or completely cold. No difference… still massive stepdown after a few seconds of operation.
The Lume1 is probably a great driver for someone seeking primarily to run their FW3 series light more efficiently on intermediate and low modes. But it’s an inferior choice of driver compared to stock if you primarily run your light on turbo and and as a secondary consideration wanted more efficiency on lower modes.
If the problem is a premature temperature stepdown caused by lack of pwm’ing the fet, perhaps that could be fixed with future programming. The lume1 would be better if it improved on the stock driver, without removing that driver’s functionality.
Agree to disagree. Any size TI host is a horrible choice for turbo especially one like this.
While there may be some way to get you closer to what you want you are probably better off just putting a stock FET driver in and flashing the latest Anduril which some say handles stepdown better.
Regardless, if Turbo is your mode of choice you need a bigger light or the original driver and a glove.