Blended Learning for Circuits and Electronics

The following was originally published in the May 2014 issue of ECE Source 

As I near the end of my 40th year as a professor of electrical and computer engineering, I remain excited about teaching electronics to engineering students. It would be natural to expect at least a little burnout at this advanced point in my career but I find I am having more fun than ever because we now have some amazing new tools available and, through a fortuitous series of recent experiences, I am meeting more and more remarkable teachers from ECE departments throughout the US, Canada and the world who want to fundamentally change the way our students learn about and with electronics.

My experience teaching circuits and electronics appears not to be typical. A large fraction of ECE students learn these critical subjects from faculty who treat the assignment as a chore maybe because their only direct interest and background comes from their undergraduate years. When I interviewed faculty at an outstanding research university recently (call it UXY), I was told that most of the faculty in basic circuits were from the communications group. This coincides with my own experience as an undergrad in the 1960s when I had a terrible experience in my Intro to Circuits course at Wisconsin. Full disclosure – I was assigned to the 7:45AM section three days a week for this theory only course, so I lacked a strong incentive to attend all class meetings. I did not have my Circuits Lab until a later semester. The students at UXY are better off in that they usually take their lab in the same term, although the schedules are not coordinated. When I took Linear Systems from the same instructor a couple years later, I was pleasantly surprised to discover that he was a really good teacher and thoroughly enjoyed the course. Unfortunately, giving students a positive experience in circuits is critical to building interest in ECE. In another recent interview, a colleague at a West Coast school whose experience teaching circuits is similar to mine, sees basic circuits as the breaking point where students either start loving EE or running away from it.

While it is generally accepted that labs are critical to providing the best possible learning environment for circuits and electronics students, little has changed in my four decades except that the instruments at most colleges are better and are interfaced with computers for control and data acquisition. They may be a little prettier than they used to be, but lab facilities are still expensive, limited access, often windowless with utilitarian desks and nearly all have the same set of standard instruments. Except for at a few schools that built expensive studio classrooms where all forms of content delivery (lecture, computer lab, experimental lab, problem sessions, recitations …) are possible in any length or combination in any class period, hands-on, hardware-based learning activities are only possible in these standard labs.

Easily the best thing about being an ECE professor is that we get to help equip energetic, bright young people with the skills and knowledge to change the world. Sometimes, when we are lucky, these changes directly impact what we can do in the classroom. Examples of the educational tools generated by the creativity of our graduates in circuits and electronics include National Instruments’ myDAQ, Digilent’s Analog Discovery, Syscomp’s CircuitGear, with others joining their ranks almost daily. For links to most products in this market, see http://hibp.ecse.rpi.edu/~connor/Mobile%20Studio/. What clearly distinguishes these products from traditional bench-instruments is their very low cost (somewhere near the price of a technical textbook) and their multiple functionality (scope, function generator, power supply, spectrum analyzer, logic analyzer …) that provides most of what is needed for analog and digital courses. They are truly the results of the relentless quest of our graduates for ever more capable and cheaper products.

It would be easier to talk about this on-going revolution in engineering education if there was a commonly accepted name for these new tools. At the recent ECEDHA meeting in Napa, Sam Fuller of Analog Devices called them Personal Instrumentation Devices. Others I have talked to have called them Hand Held Instruments. At RPI, where one of the earliest such devices – The Mobile Studio – originated, we choose to call them Mobile Learning Platforms. If you want to find information online, maybe the best terms to use for your search are USB Scopes, even though the functionality goes way beyond just simple voltage measurement and PCs are being replaced by tablets and phones.

None of the names mentioned is really fully descriptive or understandable and the overall market is changing so fast that the focus on the hardware probably limits discourse. Fortunately, as educators, we are better off keeping our sights on the pedagogy the new tools make possible. In the center that combines Mobile Studio (RPI, Howard, Rose-Hulman, Morgan State) with TESSAL (Georgia Tech) and Lab-In-A-Box (Virginia Tech) projects, we use Mobile Hands-On STEM or MOHS Pedagogy in honor of the whimsical units used previously for conductance. I will mention at least one other term below, but, in the remainder of this piece, I will use MOHS Pedagogy to mean the blending of inexpensive, hands-on, experiment-focused instruction with other traditional (e.g. lectures, paper-and-pencil problem solving, recitations) and, especially, newer (e.g. flipped classroom, problem-based learning, active learning) modalities.

One of the secrets for staying young, at least in spirit, is to embrace opportunities that go well outside one’s comfort zone. My most recent chance to do something with the potential to be really embarrassing was when my team (with Fred Berry of MSOE and Peter Lea of Bowdoin) was chosen for an NSF pilot program to see if I-Corps activities and training could work for educational research as well as it does for traditional technical research. This effort, with support also from Intel, took nine three-member teams through a very intense schedule of multi-day workshops and weekly online classes and meetings, both beginning and ending in DC. Probably the most demanding and rewarding part of the process was the development of hypotheses organized into a business model canvas and then getting out of the building to interview at least 100 potential customers for our ideas. The interests of the groups ranged from transition programs for veterans interested in engineering careers to teaching programming fundamentals to concept inventories. All of us were convinced we had great ideas, but none had ever worked so hard to define things from the customer point-of-view.

What did we learn from this experience? Some of the real nuggets we received were not totally new, but our overall approach went through quite a significant change. We learned that the teaching of circuits and electronics labs is largely driven by the nature of the available facilities. Most schools have moderately sized labs serving 10-25 students, requiring multiple sections scheduled throughout the week, often into the evening. Most labs are written so that nearly all students can finish them in the allotted time, although many also have some open shop time for students to catch up, if necessary. Most students do what they can during their class time and then make the most of the experience in their reports. A faculty member from a large East Coast community college extended her work with her students as long as scheduling permitted and then continued to work with some of them using the lab set up she maintains in her office. We talked to quite a few such dedicated and passionate faculty who do whatever is necessary to make sure their students learn the material. They are frustrated because they cannot take care of everyone. We also came to appreciate that we were taking a similar facilities focus in our work by starting from the hardware and not pedagogy. We have these cool new tools and were thinking of how they change what we can do, rather than starting from what we need or want to accomplish and then seeing what the news tools can make possible.

We also learned (or confirmed in this case) that the facilities used for circuits and electronics labs were unexciting. Another topic discussed at length at the Napa ECEDHA meeting was how to recruit and retain a more diverse and larger ECE student body. Everyone in the room loves being an electrical or computer engineer and struggles to understand why so few young people want to join us. If we really think being in the ECE community is so great, why aren’t we building hands-on, active learning environments and highlighting them as showplaces to excite our future brothers and sisters? This idea partly came from some interviews with admissions personnel who immediately appreciated the potential to build on the nascent ECE interests of students who attend our pre-college summer programs by using MOHS tools to enable them to experience real ECE. Summer programs, like a lot of K-12 outreach, tend to emphasize mechanical and structural engineering (even those with a strong robotics flavor) over ECE and CS, which tend to make the enrollment imbalance in engineering even worse. One admissions officer even suggested buying a mobile device and a parts kit for each future ECE student to encourage them to tinker and provide them with a set of tools to use in their future courses. The return on a couple hundred dollar investment should be quite good.

During the present year, both before and after I-Corps, I have also gotten to work with an amazing group of schools – the HBCUs with ECE programs – on a new project using Experimental Centric Pedagogy (the alternative to MOHS I mentioned above) to address their recruitment and retention issues by providing a richer learning experience for their students. With leadership from the two schools already using MOHS(Howard and Morgan State), thirteen institutions are now building a model program using mobile instruments that should benefit the entire ECE community.  The lessons learned from our I-Corps experience have definitely provided a valuable contribution to this effort.

Another I-Corps lesson is a corollary to the cool learning approach that attracts new students. It is better if our students get to solve problems like real engineers if they are to develop the skills and confidence to become electrical and/or computer engineers. Real engineers do not sit around just solving academic problems, like I did as a sophomore. They do simulations and experiments with the goal of creating a workable systems model that can be used to produce the products their customers need. In recent years, with the availability of laptops, we have been able to add simulation activities to our circuits and electronics courses. Now with USB-based mobile instruments, our students are able to also do as much experimentation as necessary in their courses, no matter where and when they meet. It is no longer necessary to wait for a turn in a lab. They can also be given experimental homework. In fact, their entire lab experience (following the Lab-In-A-Box model) can be done at home. We can all give our student a learning experience that completely blends all the approaches taken by working engineers in ways that were never before possible.

I offer an example of what we can now do from the Electronic Instrumentation course I offer for large numbers of engineering students outside of ECE at RPI.  I asked my students to design a hardware switch debouncer using a 555 timer chip. I let them use any design they find online. To test out their design, I had them first simulate it with PSpice using an idealized switch signal with some bouncing. None of the designs they can find online will work with this sequence unless they change some components. Then I created the same sequence as a csv file and used this file with the Custom feature of the Analog Discovery Arbitrary Waveform Generator, so that the identical input could be used to test their hardware implementation. The students were able to test their design and see essentially identical responses from both simulation and experiment. I did this because I wanted the students to know they could simulate exactly what they are seeing experimentally, which validates the simulation. Then they can use any information easily obtained from the simulation to characterize their experiment. For example, I ask them to find two designs that use different average power. There is no direct way to measure power with standard instruments, but with PSpice it is trivial. This project involved roughly equal parts traditional hand calculations, simulation and experimentation and produced a working system.

I would like to end with a challenge – should we go as far as possible to eliminate traditional labs in ECE but rather incorporate experimentation as part of all standard undergrad courses? I would argue that traditional labs should indeed go and the use of lab facilities change focus to providing high performance or specialized measurement capabilities as a complement to the MOHS approach. We should change from labs being an add-on experience to becoming an integral part of a fully blended learning experience for our students. All the types of new pedagogy mentioned above (especially flipped classrooms) can then be incorporated based on the interests and capabilities of the students and faculty and not on what one can find in the lab.

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