In this work we present an inexpensive experiment proposal to study the kinematics of uniform circular motion in a secondary school. We used a PC sound card to connect a homemade simple sensor to a computer and used the free sound analysis software Audacity to record experimental data. We obtained quite good results even in comparison with the commercial PASCO PS-2103A motion sensor. We show that our experimental set up is suitable to perform experiments in secondary schools and allows the teacher to prove the relationship between angular velocity, the scalar one and the radius of the motion.