BOBShield: An Open-Source Miniature "Ball and Beam" Device for Control Engineering Education. - Gergely Takács; Erik Mikulas; Anna Vargová; Tibor Konkoly; Patrik Síma; Lukás Vadovic; Matús Bíro; Marko Michal; Matej Simovec; Martin Gulan (EDUCON, 2021)