Abstract:

The surge of low-cost devices like the Raspberry PI or Arduino microcontrollers has enabled a lot of people to do many technical things by themselves. Domotics, automatics, security, maintenance and a large etcetera of fields have received a lot of attention from amateurs (the so-called ‘maker movement’) and professionals as well. The realization of prototypes became cheaper and easier. The problem was that some fields still lacked of low-cost devices to accomplish this kind of easy prototyping and learning. One of these fields was radio communications, but this changed when a group of hackers realized that a USB dongle intended to receive TV signals could be used as a general purpose software-radio device. This device is the RTL-SDR.

The goal of this paper is to assess some improvements on the way some engineering disciplines are taught, like signal processing, communications electronics, antennas, etc. To do so, we introduced a low-cost device, the RTL-SDR, to help students to learn all these concepts in a practical way. This device (which costs only 10 €) was employed in many different courses: an undergraduate, graduate and a MOOC. The approach followed in the face-to-face training courses the approach was the following: instead of performing all the practical work in the laboratories, students were able to take away the RTL and do their homework out of the lab. This has improved the participation in class and students were also more skilled than previously when they only worked with real devices in the lab.

Regarding the MOOC, the approach was also innovative because in this kind of courses is very unlikely to have hardware involved in the teaching lessons. We advertised the course, encouraging students to buy the hardware in advance and a significant number of them bought the device and completed the course. There were 1020 students enrolled in the first edition of the course which attracted a lot of attention in the SDR field. The course lasted for five weeks and also had Mathworks providing support to students on everything related to the setup & configuration of the software framework (MATLAB & Simulink). Social networks like Twitter or Google+ were also employed to let students help each other and increase the participation in the MOOC.

The face-to-face courses started back in fall 2015 and have been taught every semester since then. The first edition of the MOOC, entitled “Software-Defined Radio 101 with RTL-SDR” started in September 2017 and there is already scheduled a second one for January 2018.

We have analyzed all the metrics that we have access to: video reproductions, test attempts, punctuations, etc., so some quantitative data is provided regarding this educative project.

Finally, our impression is that students really appreciate this way of learning some subjects that are usually taught in an old-fashioned way, with some restrictions to work in the lab with real devices. The flexibility provided by these devices and the easiness to find information about them in the internet was a key to the success.

Keywords:

Electrical Engineering, MOOC, undergraduate, graduate, low-cost devices.