Arduino and hobby electronics. It started out as a continuous loop pad dye machine to save me having to dye fabric by hand, strictly mechanical, but then I wanted to automate adding the chemicals at the right times. Then it was keeping the dye liquor a consistent temperature. Then it was draining the trough automatically. Then I figured out I could design my own PCBs and have them fabricated. It just keeps going...
I'd like to know more about this. I'm trying to get into electronics and hardware automation but feel overwhelmed since I don't have any idea about electrical engineering
Honestly my recommendation would be to start off with some microcontrollers/Raspberry Pi and some breadboards and go from there. That way you can uhhh trial and error your way to something that works and worry about the "engineering" part later, when you have gotten your feet wet :D
There are some simple Arduino starter kits for example that give you the basic things + a bunch of sensors and motors to play with. I got started myself with the Elegoo Arduino Starter Kit (~50€).
Along the way it's probably going to be helpful to look up some course on electronics basics, specifically digital circuits and then analog circuits if you're feeling adventurous.
Best piece of advice I can give about learning anything (that doesn't involve risk of injury): don't try to learn everything there is to learn. Decide what you want to do and learn what you need to do that. Tell me something you'd be interested in doing...