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!