This paper discusses the evolution of an interface used to introduce eletronics in the foundation design course at the School of Architecture at Universidade Federal de Minas Gerais, Brazil. The use of this interface by the students triggers the discussion of the possibilities of new technologies in architecture and initiates a tactical learning process in which the students are responsible for the very content they are learning. This interface introduces the discussion of interactivity and indeterminism, crucial to the development of the two main works of the course: an individual interactive object and an urban interactive intervention in group.