A free speed bump, and firmware you can trust - two big things in this one.

The PolyKybd now runs its RP2040s at 200 MHz instead of 125/133 - and no, this isn't an overclock. Raspberry Pi certified the chip for 200 MHz in 2025; In the keyboard space I haven't seen anybody interested, in QMK there is no support for that. I would say for 99% of all custom keyboards the standard 133MHz (I think via ChibiOS setup it in fact runs at 1225MHz) is enough. It just needs the core voltage nudged to 1.15 V, which the firmware now takes care of itself during boot. Fully in spec.

I also have some real number what that brins for the PolyKybd:

To summarize that:

-️ Switching apps ~28% faster  -️ Keycap redraws ~30% faster - Doom noticeably smoother (yes, it's still in there) Here in percent values:

Typing latency is identical. That's set by the USB frame rate, not the processor.

I've been looking at this for long time and really satisfied that it turned out to be a painless (well there was some modification needed in platforms/chibios/bootloaders/rp2040.c, but is OK 😉) and a real improvement.

Signed firmware!

PolyKybdHost can fetch a firmware release and flash it for you. Lovely, right up until the obvious question: what stops something else on your PC doing the same thing? The update protocol always checked a CRC, but a CRC only proves the bytes arrived intact, not if the firmware is trustworthy (Well, I hope you trust me here).

So the keyboard now verifies an Ed25519 signature over the image before it applies it, and releases are signed automatically by CI on Github.

And it is deliberately not a locked platform! If you  build your own firmware, it still flashes, the keyboard just asks you to confirm it in person (the signed firmware will flash without confirmation). For that, every keycap goes dark except two: A(ACCEPT) on the left and R(REJECT) on the right:

BOOTSEL/UF2 flashing is never affected either, so another path to flash your own firmware.

Best, Thomas