DIY Stream Deck! Control Your Stream Much Easier for Less Than £50! Works With OBS and Any Other Streaming App That Supports Hotkeys. : 12 Steps (with Pictures) - Instructables
ArdunioDECK – a DIY OBS streaming solution on the cheap. – S-Config
Use a Raspberry Pi Pico to Build Your Own Affordable Stream Deck - Hackster.io
Open Source Stream Deck Does It Without Touch Screens | Hackaday