firmware-pi-rp2040 VS DaemonBite-Arcade-Encoder

What upgrades would you recommend as an improvement on this? - Use keyboard layout editor to design a backplate and pay a local lasercutter to cut a metal sheet for you. I'd recommend buying a pre-made bamboo storage box for a few £s and use that as your box. If I didn't already have the Arduino, I'd get a Raspberry Pi pico clone and use better premade firmware.

This

Microcontroller: Arduino pro micro clone. Sells for peanuts on Ali Express. I have no coding experiennowledge. I tried to use this guide, but it only made the controller show up as a generic controller on windows/Linux. SF6 Didn't recognise the controller. So I programmed the Arduino as a keyboard and now it works fine on PC and Steam Deck.

I've had a great experience with Arduino Pro Micro's running the DaemonBite firmware, and the RPi Pico GP2040 firmware should be similarly great. Both have extremely low latency. The Brook Universal board is another good one. Other than that, I usually just use either a DualShock 3 pad over USB or a wired 360 pad. I also like the iBuffalo SNES pad and Logitech Precision pads.

The NEO2USB is just an Arduino running the DaemonBite firmware. If you (or someone you know) can do basic soldering and can follow a tutorial for loading code onto an Arduino you can DIY an identical adaptor for about a third of the price of the Neo2SD. If you can get access to a 3D printer there are also case designs available for free.

If you can solder (or know someone who can), you could swap out the usb encoder for a Daemonbite and that would give you less than 1ms of input latency.

I'm not sure, I only use it for console controllers, but I would assume so. This GitHub repo has the pinout for arcade sticks: https://github.com/MickGyver/DaemonBite-Arcade-Encoder

I had one of those pcbs, the input lag is bad and inconsistent, the build quality it's very cheap, and has no xinput support... Nowadays are better alternatives like Brook Zero-Pi, Tachyon PCB, or DIY stuff like GP2040-CE ( https://github.com/OpenStickFoundation/GP2040-CE ) or DaemonBite ( https://github.com/MickGyver/DaemonBite-Arcade-Encoder )