From what I can gather the SP10B uses an XC9104 as the main booster - output PWMed via FET not sure about that, but PWMed in some way - plus what I believe is an ME2188 as the auxiliary booster (always running, no-load input current in the range of 10µA) for the control circuitry.
Adapting Anduril to run on this shouldn’t be too hard, it would be 1-channel PWM only (though one could probably do proper moonlight off the aux supply and a dedicated pin+ resistor).
@Toykeeper - this would make use of that control pin we talked about in the FSM thread, remember? I know that Lexel knows what I mean
If Sofirn were to keep the boost circuitry - it seems to do a fairly good job at regulation - then 14500 and AA should work fine. But you’d have to come up with some way of doing the LVP for 2 different chemistries (and this would have to use the old-school voltage divider of course)
There are ways… but it would take some doing. I’m no EE, but I have played with small boost circuits for my illuminated tailcaps that can run off an AA or 14500.
I’ve used the TPS61099x (such as the TPS610993) to boost the voltage to a given output (eg: 3.0V) regardless of the input voltage. Runs fine down to 0.7V and will switch to pass-through mode if the input voltage exceeds the desired output voltage, so it’ll handle AA and li-ions just fine. Then use that boosted voltage as the input to any of our ATtiny’s. This chip is tiny, and works with just a few external components (also tiny). Very efficient and very low IQ.
Another option is one that I’ve never played with before, and you don’t see much talk about… the ATtiny43U. It has a built-in voltage boost circuit, though you’d still need the external inductor and capacitors (MC webpage, design guidelines).
This is all just providing a small amount of boosted juice for the ATtiny itself. This wouldn’t be for boosting the LED juice… just controlling the circuit that does so.
Can you check with Barry et al about the possibility of TIR optics? I’m unsure of the use-cases people may have for it, but in a smaller host, I’d assume it’d be for closer-up work rather than throw, so smoothing the beam out with TIR might be good.
