Convoy M21B vs Convoy S21E

“Fantastic, I definitely need this comparison. I've been contemplating the M21B LHP73B. But i love the well defined smooth beam in the L21A now that I've seen it. What's your preference now you've had them both of you could only keep one and why?”

“I love Simons S21E. One of the best medium sized EDCs in my opinion. Very compact for a 21700 light, can USB charge, has a reasonably positioned side switch, can take either TIRs or reflectors, can take 3535 or 5050 emitters and it exists in a lot of colors. My only gripe with it, as with many Convoys, is the driver. The 6V boost driver (for B35AM, XHP50.3 or SFT-70) is actually very efficient, but it has its shortcomings - mainly (very) slow charging and a weird UI. No shortcut from moonlight into the regular modes as well as 10c lockout makes this light more annoying to use than it should be. That's why I decided to bring my two hobbies together and make a custom driver for it. The pictures show a render of the current state (needs some more checking but is ready to order apart from that), as well as a screenshot of the layer stackup with all copper zones disabled to show the mayhem. There is not a single spot on the PCB where I could still place a via without interfering with any of the copper planes or components... The density of this PCB is insane. Most passives are 0402 and the spring is a Convoy 6mm cylindrical type, for scale. Features: * 6V 5A boost driver (on paper, whether that is thermally possible or needs software throttling is to be seen) * 2 shunts for proper HDR (very low moonlight) * 5V 3A buck USB charger with proper USB-C negotiation * 5V 3A USB powerbank functionality * RGB AUX * Inductor and reverse polarity protection FET picked on purpose to allow as little losses as possible while still being rather cheap and easily available parts * Flashing over USB - just losen the tailcap, hold the e-switch and plug the USB cable in while keeping it pressed to enter USB DFU * Highly configurable charging IC - you want to limit the charge termination voltage to 4.0V, or limit to 1A max charging? All possible. Same applies to the powerbank settings. In addition (this is the fun part) - the hardware is ready to be configured via USB in runtime, e.g. without (re)compiling or flashing a new firmware. My final goal would be a tool similar to VIA for custom keyboards. Plug in the light, open a config tool (either website in Chromium browser or electron app) and set things like amount of modes, mode current, enable/disable blinkies, control the AUX leds, configure charging current and termination voltage etc all from a nice UI (or terminal if you feel like punching commands and/or have a hatred for anything Chromium). How the hell does all this work with Anduril, you may ask? That's the catch. It does not. This requires an entirely new UI, also because this light uses a MCU I have not seen yet in the flashlight world - an STM32F042. This chip was chosen due to the very small footprint, while still having crystal-less USB capabilities and USB DFU programming out of the box. And this will be my biggest challenge for this project. The software support. I am a hardware developer by dayjob, and while I do have some coding experience, I hav”