Abstract:

The course “Pulse and Digital Devices” for students-bachelors of the specialties “Electronics”, “Computer Control and Automation”, “Information and Communication Technologies” and “Internet and Mobile Communications” is one of the basic disciplines in their curricula, where students learn how different digital devices work.

One of the topics in these courses is magnitude comparators. These devices are important because they are combinational logic circuits intended for the comparison of two binary numbers determining whether the first binary number A is equal to, greater than, or less than the second binary number B. The main challenge is to build such digital comparators, especially for binary numbers with more digits, and for this task, students use experiential learning. Experiential learning is an important method for engineer students because they can learn from doing, from their mistakes, and how to use different software products and real equipment.

During the last academic year, students had more challenges, because of the pandemic of COVID-19 and the transition to distance learning. Lecturers need to find really quickly a solution how to present the material and how students can do exercises by themselves. A solution is to use different active methods in all classes and for the exercises to use software programs, which students can install on their personal computers.

To better understand the material studied, students must perform different tasks. Also, they have the opportunity to use software programs and real laboratory boards (during face-to-face classes). With this variety of tasks, they not only master the material but also develop basic abilities to work in a real environment.

This paper presents active learning methods used in the classes when teaching the topic “Magnitude Comparators” and the tasks that students need to perform, using experiential learning with the solutions. An approach for synthesis a magnitude comparator comparing two five-bit binary numbers is considered in the paper. The magnitude comparator is implemented in Logisim and tested for different input combinations. Then the circuit is built in the environment of ISE Project Navigator needful for programming the FPGA-based laboratory board, developed at the University of Ruse and used in the educational process in the course “Digital and Pulse Devices”. The issues for implementing the comparator with integrated circuits, as well as the cascade connection of comparators are briefly covered.

Using practical exercises with the lab board excites students’ minds, captures their interests, and helps the students understand the concepts better. By applying active learning methods students are more interested to learn the specific topic and the lecturer can get feedback on how they understand the material and what needs to be more detailed explained or which students need additional attention or more tasks to perform.

Keywords:

Digital devices, Experiential learning, FPGA, Logisim, Magnitude comparators, Xilinx.