I can second this as well, Arduinos have a bad rep for being too beginner-focused but AVR is a super solid platform and you can do a ton with them. I'd pick Ard

I can second this as well, Arduinos have a bad rep for being too beginner-focused but AVR is a super solid platform and you can do a ton with them. I'd pick Arduino over RasPi for a starter project anytime.