Alright it works for the smooth mode but not for stepped mode, I guess one step needs to be exactly on the transition level so that it blinks, which is technically possible but then the ramp and number of step are tied together and the later can’t be changed afterwards in the UI.
Just fyi, I'm reading all this and do understand most of it. Thanks!
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Btw: ToyKeeper has implemented higher resolution PWM and “jump start” yesterday in the anduril2 branch.
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Ok, I'll bite. What's jump start? And how exactly, what exactly did she do with higher PWM's?
Brief list of changes here over the last day or so: https://bazaar.launchpad.net/~toykeeper/flashlight-firmware/anduril2/changes/606
She took it from 598 to 606, mostly on the KR4.
"added a "jump start moon" option for hold-from-off, for lights with slow-activating circuits (briefly pulses the light at a higher level to wake up the circuit faster)"
Guess this is for problems with the KR4 as well, nothing like a new feature.
With the Noctigon linear driver the LED can take a second or so to lit up on the lowest level (not sure why), with jump start apparently it starts at a higher level then go back to the actual level.
Dynamic PWM : likely to prevent noise during thermal throttling, since the PWM runs at 4kHz (10bits) in the Noctigon driver the bulk 0805 cap can sing. So here resolution is decreased to 8 bit for the FET and frequency increased to 16kHz so that it’s not audible.
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No, to change the timing to get higher resolution in the lower levels. Like 1/10, 1/9, 1/8, 1/7, 1/6, 2/10, 2/9, 2/8, …
Ah yes, I assumed that was the implementation starryalley’s dynamic resolution but no.
I reflowed my first 1616 MCU last night on my tweaked gchart 20 mm driver boards. It's just an old FET+1 but what a PIA soldering that VQFN-20 part. I must have made like 8-10 attempts at it, but hoping the next will go easier. I made my own 22-23 mm version that can be sanded down a couple mm's to fit various lights.
One of the 23 mm's sanded down will be going in a cheap 18650 small zoomie with an e-switch. By cheap I mean like paying $7 shipped.
I think what I'll do is use very little solder paste for the middle pad, and don't reflow the pins. For the pins I'll hand solder with just laying a thin stripe of solder paste across each side of 5 pins, then working it with the small tip iron. Might need the solder wick as well.
For the one I did last night I first tried paste all around and ended up with big balls of solder on each side, crossing all 5 pins. Eventually what worked was hot air removal of the MCU, solder wicked the pads clean, then hot air reflowed the MCU back on. I think the MCU had enough solder on the pins to bond well and still stay clean. All this time the driver was on a 100C hot plate.
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Personnaly I’m using a stencil I made a while ago, just for the 1616.
Another way is to tin the pads and then reflow.
Ohhh, maybe the tinning method will work for me. Think gchart said the stencil didn't work well for him.
Hmm, maybe it’s because I’m using printing grade paste but I haven’t had any issues with stencils.
It’s been a while since I’ve used a stencil. I haven’t used one since getting new higher-grade paste. I need to try again.
So is that type 4 or 5, like described here: https://fctsolder.com/solder-paste-type-3-vs-type-4-vs-type-5/
I had to google it... 
Looks like 4, or better yet 5 is better for small parts/pads.
Is higher grade the type 4 or 5? Any links, let me know. Thanks guys!!
Out of curiosity, what thickness of stencil are you using? I think that could play a big factor as well.
And I’d have to look Tom, but I think I got the type 5 stuff. That and my old stuff was crusty and had been re-fluxed several times.
Mine is T4, it’s just that the printing grade one is less fluid, I think it’s so that it releases well when lifting the stencil, though I actually never tried stencils with the dispense grade (syringe) I have too.
0.1mm steel.
Oh I think puting flux in paste is very bad, I tried to put flux in some of the print grade to make it more fluid, one month after it didn’t work at all.
I use Chipquik no fridge (quite practical) Chip Quik - Solder Paste No Fridge (15)
Pot is print and syringe dispense.
But it’s not cheap
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Ok, if I were to order this, I think I would want for solder paste:
https://www.chipquik.com/store/product_info.php?products_id=470011
and for flux:
https://www.chipquik.com/store/product_info.php?products_id=310017
I think the tack flux is the typical type? Not too thin, watery?
And definitely the leaded paste for me.
That paste would be amazing if refrigeration is not required. Any downsides?
Oh, by "print" you mean using stencils?
Update: Just found it on Amazon US, cheap but Halogen free: https://www.amazon.com/Smooth-Leaded-Solder-Paste-Syringe/dp/B08KRR7PV4/ref=sr_1_6?dchild=1&keywords=solder+paste+t4+syringe&qid=1629334633&s=hi&sr=1-6
Regular, leaded, more $$$:
Ooops! My bad! Those on Amazon are not the Thermally Stable ones (TS...)
For the flux I use SMD291, it’s not too thin I think, the one you linked is a RMA type flux and isn’t described as ”no clean”, that said it’s still RO*L*0 I.e. low activity so maybe it’s fine ?
I haven’t noticed any issue with the no fridge paste, but mine only 6 month old.
Print grade (sold in pots, see in the datasheet) is specifically for stencil, it doesn’t work well for applying the paste manually, it doesn’t stick well and kind of stays on the tip of the syringe. I’ll test stencil with the dispense grade (sold in syringes) next time.
This is what I've been buying, current syringe from Jan 2021: https://www.amazon.com/gp/product/B017RSZFQQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I keep it in the refrig, but occasionally forget and leave it out for a day. It's really not sticking too well, and stays on the syringe as you described for the print grade. Not sure if it's from the age, leaving it out, or what. Think it's worse now though then it used to be, not sure. It's probably dried out some.
Yea, that RMA291 looks good - thanks! Now just wondering if I should commit to the $$$... Wish I had the ability to design and layout my own drivers 
. You two are doing great jobs on the drivers, btw!! Very jealous
Well without talking about the circuit design, it didn’t take me too long to learn how to use an EDA software (I use Kicad, I think eagle and easy EDA are also popular ?) just by following tutorials. Making drivers that fit in whatever host is quite rewarding.
For the circuits, FET+7135 are very simple and there must be some shematics on the forum, the linear driver above if it works properly I’ll share the schematic (the boards shipped a few days ago).
For the paste not sticking well, pre applying a thin layer of tacky flux helps (not too much otherwise the paste spreads out)
Using a small dispense tip is also better, less area to stick to, I use red plastic ones… hmm 24G I think it is (they are color coded). For precise dispensing, using a small syringe is incomparably better than the one the paste comes in, I use 1mL ones.
Edit : thanks for the compliments 
Yea, I know the ATtiny85 FET+1's all too well, and have OSHPark drivers of them to accommodate just about anything, many dating back to 2017 from DEL and Texas_Ace mostly. CC linear and optionally a full FET with power efficiency and no visible PWM is preferred now.
Ideally, the most desired support would be having true regulated constant output (lumens) up til a certain power level, depending on the light's design, no visible PWM. Not sure if this requires buck/boost - think so? But certainly for a single cell driving a 6V or 12V LED, then boost is all that's needed, I assume. Same for just buck needed if 2S-4S cells, 3V LED. But certainly for single cell 3V lights, buck/boost with a wide open FET channel would be the best setup?
Gchart's runtime graphs on the SP10 Pro are dang impressive! (https://budgetlightforum.com/t/-/56521)