Personalized learning is one of the main targets of the Artificial Intelligence in Education (AIEd) community. The potentiality of Artificial Intelligence (AI) techniques in student profiling could be very beneficial to support teachers when using technology in their classes. This way, each student could follow a learning path adapted to his/her progress, allowing the teacher to focus on those who require special attention. The current work is focused on this scope, and it presents the initial version of ProgTutor, an intelligent tutoring system designed to teach fundamental programming principles to high school and university students in a personalized manner. ProgTutor employs an interactive educational approach focused on solving realistic challenges with the assistance of a robot. The system uses a 3D simulator developed in Unity to take full advantage of the motivational and customization capabilities that this interface offers students. The current paper focuses on the conceptual and functional design of ProgTutor, presenting initial application results with high school students, and some interesting conclusions obtained from the teachers.