In a move to encourage personal exploration and experimentation throughout the curriculum, the ECE department has developed portable laboratories for students to purchase and use at home that support a sequence of four required courses.
Called “lab-in-a-box,” the main unit contains a powered protoboard, plus switches, a logic probe, potentiometers, clocks and LEDs and fits in a container about the size of a textbook. In addition, the kit includes a digital multimeter, some basic tools, and various wires and resistors. Software that allows the student to use the sound card of a PC as an oscilloscope for simple measurements is also included. For each class that uses the lab-in-a-box, students purchase a bag of course-specific components, such as resistors, capacitors, inductors, digital ICs and op amps. “This kit gives students the major measuring equipment and tools that once were restricted to laboratory benches,” said Robert Hendricks, faculty lead on the effort.
Beginning with the sophomore-level courses in Electric Circuit Analysis (ECE 2004) and Introduction to Computer Engineering (ECE 2504), students use the laboratories for homework and project assignments. The kits’ special functions enable them to be used again in Digital Design (ECE 3504), required for CPEs and AC Circuit Analysis, (ECE 3004), required for EEs.
“Students are coming to college with less hardware experience than in the past. This makes sense when we consider that most digital and analog technology is integrated onto one miniature board for most applications. But it makes the introductory material in ECE seem very abstract to the students,” Hendricks said.
“We wanted to find a way to give them the experience and opportunity to explore on their own. After exploring many options, we decided to expand on the ‘Lab-in-a-Box’ concept first proposed by Rich Christie at the University of Washington.”
The biggest advantage is that students can now try out circuits and designs without needing to go to a special room or take a special course, according to Hendricks. “In laboratory courses, time is restricted and if students want to try something different from the assigned projects and experiments, they cannot always get that opportunity. With lab-in-a-box, students can wire up a design any time of day.” The personal laboratories are part of a curriculum overhaul designed to incorporate more experiments and research with ECE theory. The curriculum revision has been funded by a grant from the National Science Foundation (NSF). Working with Hendricks are Kathleen Meehan, William Tranter, William Baumann, Nathaniel Davis, and Lynn Abbott.
For Introduction to Computer Engineering and Digital De-sign, the new laboratory kits replace older pencil-box kits that were assigned to students each semester. The new lab-in-a-boxes provide expanded capabilities for projects and designs. The circuit analysis courses, however, never had hands-on components, and the team developed assignments to help make them more concrete.
The initial projects, developed by Kevin Lai (EE ’05) and Brac Webb (EE ’05) under the auspices of an NSF REU grant, include about a dozen simple experiments designed to help the student understand the introductory materials taught in the lecture pat of the courses and culminate in a pair of introductory engineering design experiments where the students build an analog voltmeter or develop a traffic signal with a blinking arrow. Lai and Webb also were involved in developing new projects in the electronics laboratory course that relate to technology students use every day.
The lab-in-a-box projects were first used by a Circuit Analysis class this past fall, and this spring all the sophomore circuits classes incorporated the projects, using older pencil-box kits. The custom-made lab-in-a-box kits will be available for students beginning fall 2005.
Students in the test class appreciated the flexibility the kits offer as well as the opportunity to see first-hand the concepts discussed in class. “The boxes were great,” said Chris Headley (EE ’06). I could carry it around on campus, do them in Torgersen, or work in my apartment. I could leave a circuit, close the box and finish later.” He described the difference when he took an electronics laboratory course, where the time was limited and students were required to turn in their designs. “With the lab-in-a-box, we had a week to do the projects, so we could toy with them.”
Elizabeth Goldberg (EE ’07) enjoyed being able to do the projects at home. “I could do it any time I wanted, like 2 a.m.” She also mentioned appreciating being able to discuss and troubleshoot the projects with other students, within the confines of the Honor Code. The disadvantage she mentioned was getting questions answered as she worked on the projects. Both students agreed on the advantage of building the projects themselves. “It’s neat to build it on your own and figure it out on your own,” Golberg said. “Even in a lab course, you have a partner. It’s always good to know you can do it yourself; it builds your confidence in applying the concepts with the actual wires and components…One of the best parts was seeing what the components actually look like,” she added.
Headley said that working with the circuits being studied helped him visualize the concepts. “We were able to see that things are not as simple as the schematics make them look,” he said. “On the bread boards, we have bus lines and connection lines and had to make sure we were grounding the circuits and that we measured the voltages in parallel and the currents in series. That isn’t evident by looking at a simple schematic.”
They learned from their mistakes: Goldberg by blowing a fuse on her multimeter and Headley by using a 2-ohm instead of a 2,000-ohm resister. “I burned myself pretty badly,” Headley said, “but I really learned to double check my circuit before turning it on.”
Goldberg she realized in later courses how the concepts taught in the introductory circuits course were truly a foundation. “After just a semester, I can tell how important the course was. The following courses assume you know that material...Looking back, I’d advise any students taking the course to make sure they can do everything on their own because it’s skills and knowledge they will use for the rest of their career.”