39
Summary
Great hardware, poor software – that’s the Sofirn SK31 in a nutshell. The combination of a powerful LMP LHP73B with a well-regulated driver, a two-stage tail switch, a separate switch for the lockout and a screwed cover for the USB-C charging port provide the perfect hardware foundation for a great flashlight.
The operation is all the more disappointing. The two-stage switch leaves much of its potential unused. For example, there is no direct access to the lowest or highest brightness level and in Tactical Mode, the switch must be held halfway down for a full five seconds to keep the flashlight on. Minor firmware bugs make the overall experience even less enjoyable.
The full review is available here:
English review at BudgetLightForum
German review on my website
No idea about the CH32V003 but the Padauk MCU (3 cents in qty 1000 on LCSC iirc) has near zero current drain in the deepest sleep mode. Here's a LED blinker with a Padauk (I think not the 3 cent model but not much more) using 1 microamp on average, works out to 22 years on a cr2032 coin cell: https://cpldcpu.wordpress.com/2021/02/07/ultra-low-power-led-flasher/
Anduril currently relies on AVR series MCU's and sleep current is also in the microamp range. Anyway take apart some flashlights made in the past 10 years, before telling me that any but the simplest ones don't have microprocessors.
Added: the CH32V003 appears to have a standby mode using 10 to 11 microamps. https://curiousscientist.tech/blog/ch32v003j4m6-low-power-modes