Thursday, May 21, 2015
(Note: An edited version of this blog will appear on TI's e2e site)
Fashion designers can create glamorous outfits from a variety of materials. But they can also design stuff with the same material we’ve been using for decades. They are able to achieve this due to their passion and zeal. Similarly, any electronic system design requires the passion to solve a problem, and innovative approach to solving it using the wide breadth of parts and components and the necessary core skills to convert the idea to a solution.
At the Division of Electronics and Communication Engineering (ECE) at NSIT Delhi, we understand that books and lab work aren’t sufficient to give an engineer the required design skills. Hence we conduct three-week Winter Training programs at the end of 3rd and 5th semester of their course of study. These training programs give engineering students hands-on experience to design electronic products.
Design continues to be important in all walks of life. Let me specifically talk about the latest program that we conducted for 3rd semester and 5th semester students a few months ago, in December 2014.
The 3rd semester students had little or no skills in engineering. The 5th semester students had already acquired some skills as part of their 3rd semester training the previous year.
Preparing to Jump
The 3rd semester students had until then studied about basic semiconductor components, circuit theory and analysis. The associated laboratory experience had exposed them to simple experiments performed on solder-less breadboard – which is fine as a lab exercise, but is not the professional method of creating circuits.
In order to generate interest in electronics circuits, as part of the training program, we conducted a demonstration of several projects and products using TI semiconductors and ICs, that have been developed in the Texas Instruments Centre for Embedded Product Design (TI-CEPD) at NSIT. This introductory event serves the purpose of grabbing their attention and they get hooked and really want to get into the depth of design.
But first things first!
As part of the training program, we convey to the participants that the foundation of all electronic projects, products, systems or what have you, is the power supply. Without the humble power supply, no electronic system can function!
Humble they may appear to be, but how do they work? We covered the evolution of power supply circuits from simple shunt regulator leading to the classic LM723, which is a linear power supply regulator IC from TI. We covered the classification of various power supply architectures, linear as well as switching power supply designs. These are precursors to eventual hands-on activity related to the design of a linear power supply based on TI’s LM723 voltage regulator IC with short circuit protection of various output voltage and current specifications. The participants then fabricated a PCB for the power supply and soldered all the components. Once that was completed, they tested the power supply initially with a multi-meter and later on, the power supply output characteristics were evaluated using an active load. An active load is a useful piece of test circuit that we designed using TI’s LM358 dual op-amp. The active load helps in testing a power supply output characteristics by providing desired load to the power supply. By setting the active load to draw current from the power supply covering the entire expected range, you can plot the characteristics easily. Without an active load, you would be forced to arrange various load resistances of appropriate value and wattage. This working model of the power supply becomes the property of the participating students, to be used with anything they want to design in future. Below, you see a picture of the power supply circuits made by several groups in various stages of completion.
Here is a picture of the active load that was used to test the power supply and the output characteristics for this power supply.
From Puppy to Pro
Meanwhile, let us shift our gaze to what the 5th semester students are doing. During the time since the current 5th semester students finished their 3rd semester training in the previous year, they had taken several theory courses in electronics and associated laboratory activities. So we decided to pitch them into the world of MCU architecture, programming and physical I/O interfacing around the TI’s MSP430 microcontroller family using the MSP430 Puppy (a locally designed and fabricated MSP430 experimentation platform: http://wiki.cedtnsit.in/MSP430_Puppy).
TI has some excellent evaluation platforms including the Launchpad ecosystem for many MCU architectures. We use all kinds of such Launchpads in our activities. Yet, we designed Puppy specifically for the 5th semester training program because of financial constraints that exist in our system, restricting government institutes from spending more than certain amounts without a tedious tendering process. The Puppy was designed such that it was within our budget and was physically small enough to be inserted in a breadboard for quick and easy connection to simple electronic components.
The training program covered the MSP430 architecture, C programming using CCS, interfacing to common I/O devices and simple sensors. They had to form groups (of two) and propose a project, each of which was approved by a team of mentors. As I write this, these groups are implementing their projects, which will be ready – along with an accompanying report – by the end of the current semester. Here is a selfie of a happy Puppy posing in the company of a traditional 40-pin DIP IC for size comparison. Also seen is a project in partial stages of completion using the Puppy. When it grows up (as in, when the project is completed J), it would be an LED hourglass!
Gazing the Crystal Ball
Here’s the good news. The 3rd semester students have completed their tasks of creating and testing the power supply circuit. The training program was able to enthuse quite a few of them to think of creating more electronic circuits.
The 5th semester students are now capable of designing around the MSP430 microcontroller family and hopefully, given a task they can fulfill it.
I am certain that hands-on training of engineering students will go a long way in making them good designers. Will they end up designing path-breaking products? I am confident that some of them will do! Such programs are highly doable and replicable and I would urge fellow teachers and gurus to incorporate them in their curriculum. I would be happy to share any other information that you may desire on how to organize and implement such programs. Just drop me a line. If you are visiting Delhi, you are welcome to drop in and I would be delighted to show you around the TI-CEPD!