Summer MAth, Computers, RObotics, and Science (MACROS) classes
June 3, 10, 16, and 17 --- 10am to 12pm
Ganesh Gopalakrishnan, School of Computing, University of Utah
Due to several reasons, we are facing decreasing enrollments in computing, math, and engineering.
It is likely that by grabbing the attention of school children early, and sparking their enthusiasm
towards these topics, some of this trend can be reversed.
I conducted a mini summer camp called MACROS to learn first hand what can be done to help improve
After nearly $700 (fully refunded
by the School of Computing, minus the $40 per head fee collected)
and over 70 hours (rewarded by the immense satisfaction I derived),
I have the following (mostly positive)
experiences to report.
I managed to recruit seven students - one 8th-grader, five 7th-graders, and a 3rd-grader (who had
prior experience with hobby electronics) and showed them experiments over four 2-hour sessions
in our Digital Systems Labs (DSL). The students were also given a large kit of parts, and could do experiments
both at home and in the DSL. The contents of the kit are fully described later.
The focus of the camp was problem solving. The powerpoint presentation in Section 3
sums it all up: ``...while animals are lucky (they are born with most of the tools they need),
humans are not so lucky (they must acquire nearly all the tools they need).'' The set of tools
needed depend on the problems to be solved. For most problems, the tools needed span different
aspects of learning. It is possible to select problems where one must know a huge amount of
cross-disciplinary material (e.g., all the way from Chemistry to Astronomy and Biology).
It is also possible to narrow one's problem selection to focus
on just one aspect (e.g., software). I chose problems to include enough cross-disciplinary
aspects that also matched my own abilities.
(Note: there were many other problems that
were considered and discarded, sometimes after the required components did not arrive and/or
after the difficulty of the problem became more apparent):
While going through the above curriculum, many welcome distractions occurred quite naturally.
They will also be discussed briefly:
Generating solar electricity
- Conducting animations using stepper motors
- Constructing and experimenting with the Stiquito Nitinol robot
Eventually, we ended up needing knowledge of
basic electricity, analog electronics, digital electronics, mechanical
construction, some robotics, PC interfacing, programming, and some science.
For this reason, the class was called MACROS.
Electrolyzing water using solar power
- Making lemon galvanic batteries
- Motor/Generator arrangements
- Solar and surface-tension boats
- How 9-volt batteries explode, and what's inside them
- How to play do-re-mi by programming
- How to learn binary arithmetic through LEDs
- How to learn combinatorics through stepper motors
- Nitinol puppet / origami piece animation
- What does 40V taste like?
- Resistor color codes
- The use of speaker baffles by Oecanthus to amplify its mating calls
- How to make T-shirts
Timely help by Travis Stroud on multiple occasions, by Chris Strong, and Chris Coleman (T-shirt
preparation) are gratefully acknowledged.
Joe Zachary's help with Lab-4 are greatly appreciated.
Kristi Potter, Peter Jensen, and Geof Sawaya donated an old PC which helped us out immensely.
Geof Sawaya also built many Win'98 machines (easier to control parallel port; does not need
device driver to directy output to parallel port). Alan Nichols loaned Win'98 CD-ROM. Thanks all!
1.2 Future Plans
A positive outcome is that Joe and I plan to offer this
class again next year through the Youth Education program of the DCE.
It was emphasized time and again that the future of computing depends on knowing
basic electricity and electronics well. Many items are going to be battery-powered
(including cars); there will be computers coupled with virtually everything (mechanical,
electrical, and thermal); and one can learn many concepts behind programming far better
with actual LEDs/lights being lit, motors being spun, etc.
Last but not least, the efficient generation and utilization of energy is going to be a primary issue
facing the generation that is growing up now.
1.4 Student kits
Every student received the following:
Deciding on these parts, finding inexpensive sources, ordering them, and
building soldered ``leg extensions'' consumed a huge amount of my time! For instance,
to protect the 1 Farad capacitor (with very short legs), I soldered a zener across
(limits voltage to rated value, and also shorts away accidental reverse usage).
For each of the 7 stepper motors, I had to strip 6 of the leads and tin them all (42
tinning steps). The list goes on and on and on... (but all will be recouped when
we teach the class again).
A 1 Farad electrolytic capacitor
- 9V and 3V batteries, and battery holders
- A small breadboard
- An inexpensive but quite functional analog multimeter
- A nice 10V solar panel
- Hookup wires
- Various LEDs
- Stepper motor
- Small DC motor
- DC brushless motor (cooling fan)
- A piezo-beeper
- A mylar/piezo loud speaker
- A DS-2003 septo Darlington-pair (7 Darlington-pair) driver chip
- Nitinol wire (about a foot)
- Stiquito kit (with brass screws)
- PC parallel adaptor cable
- Assorted resistors
1.5 Generating solar electricity
Students measured solar panel output in direct sunlight. They determined the best solar panel angle
for Salt Lake City (40 degrees north latitude) for June, using sine curves provided later in these
notes. They also learned when the sun is south in June in SLC (about 1.26pm). They operated
various devices (DC motors, LEDs) using solar power. They were asked to think of perpetual motion
machines (shine the LED back on the panel!!)
1.6 Conducting animations using stepper motors
The unipolar stepper motors were bought for $1 each. The price paid was lack of documentation.
It turns out that one can measure the coil resistance and calculate safe currents. Using some
simple combinatorics, one can figure out the rotational sequence (see below):
What a good way to learn how to solve ``how many ways in which can 1,2,4, and 8 sit around a
circular dining table?''
Qbasic animation code for a stepper motor was provided. All students could follow it; some could
modify and see the results. One student went on to build a Lego crane and operated it using
a stepper motor!! (Three movies of this animation are included in my .ppt file below.)
1.7 Constructing and experimenting with the Stiquito Nitinol robot
The construction of my first Stiquito took me nearly 10 hours of painstaking work. The second only
took 5, thanks to one less crimping step for each leg (tensioning using brass screws).
I demo-ed a Stiquito crawl using a Qbasic animation program. Students seemed to follow roughly
how the program works. One student adjusted the Stiquito gait, since it was not clawing on the
left side with equal force as on the right side.
1.8 Electrolyzing water using solar power
An improvised experiment. Four solar panels in series can indeed produce noticeable amounts of
oxygen and hydrogen. Earlier experiment (throw a 9V battery into water with some vinegar) also
produced oxygen and hydrogen.
1.9 Making lemon galvanic batteries
Most students have not done such simple experiments! It is a sad outcome of modern busy
living when ordinary ``kitchen electronics'' experiments are not being conducted...
Three lemons in series with copper/steel pins could buzz the piezo beeper.
1.10 Motor/Generator arrangements
We explained that this is how their Toyota Prius car worked. We lit LEDs using a DC motor spun
Then two back-to-back DC motors operated as follows: when you crank one, the other cranks,
thanks to the electricity generated by one.
I explained that large locomotives and ships use this arrangement to transmit energy from
their engines to their wheel/propellor motors.
1.11 Solar and surface-tension boats
A raft with a solar panel and a brushless motor floated on water and moved.
Students were told of surface tension boats (coat one side of raft with soap
to lower surface tension and thus produce motion).
1.12 How 9-volt batteries explode, and what's inside them
An accidentally shorted new 9V battery exploded, revealing that indeed it contains
six AAA batteries inside!!
1.13 How to play do-re-mi by programming
By writing programmed delay loops, we produced do-re-mi. Illustrated use of single stepping
and debugging loop programs.
1.14 The use of speaker baffles by Oecanthus to amplify its mating calls
A bare speaker produces weak sound because the pressure created in front ``flows into'' the rarification
behind (and vice versa) upon each swing of the speaker cone. By cupping the speaker, one can prevent
this air flow, thus creating a speaker baffle. The Oecanthus (snowy tree cricket) uses a leaf as
a ``speaker baffle'' to amplify its mating calls. A picture of Oecanthus adorns the T-shirt given
to the students on the last class (JPG image below).
1.15 How to learn binary arithmetic through LEDs
Students used DS-2003 for driving the LEDs, stepper motors, and Nitinol wires.
Students figured out how binary combinations can light one of four LEDs (e.g., 13, or ``1101,'' helps
light the first, second, and fourth LED from the left.
1.16 How to learn combinatorics through stepper motors
Algorithm to figure out stepper motor poles:
All the BASIC programs used are enclosed on this webpage.
connect at random, and
- excite using all the following circular Binary arrangements till one works
1.17 Nitinol puppet / origami piece animation
A wooden ``pull string doll'' I bought from Vienna was an ideal candidate for a ``Nitinol enhancement.''
It animated beautifully through the help of a simple Qbasic program.
1.18 What does 40V taste like?
I connected four solar panels in series (40V) and used my usual ``quick measurement method for low voltages''
(I lick the poles). It zapped my tongue hard! Seeing the recoil, the 3rd-grader very much wanted the
experience, and he too was happy to get a zap on the tongue. I warned the class against bigger zaps on the
(I can use my tongue as a battery tester, and classify good / bad batteries in the 1.5 to 9V range...)
1.19 Resistor color codes
The students really loved learning about resistor color codes (they all got this!). This helped them
fish out resistors from an assorted pile. They learned Ohm's law and used it to calculate protective
resistors for LEDs of various color.
The students learned about the LED revolution (the illumination technology has strongly embraced LEDs).
1.20 How to make T-shirts
We made cool T-shirts! The Oecanthus adorns the front and the Stiquito adorns the back. The SoC
logo is on the back!
The Oecanthus image is courtesy of Prof. Tim Forrest, Prof. of Biology, UNC Asheville.
He requested a T-shirt himself (and I am sending!). Prof. Forrest also teaches a summer
camp, taking kids out to dig out various insects!
2 Summary of Online Material
These are the lecture PPT and notes + figures that explain what
went on in this class.
Some PPT slides with movies and sound are in Section 3.
- Some notes, with accompanying figures are in Section 4.
- The nice Oecanthus fultoni (Snowy tree cricket)
image that was used to motivate speaker baffles
A JPG image is
- We used this
chart to calculate the best angle in which
to situate a solar panel in Salt Lake City. We also looked at the sunrise/sunset
chart for SLC for June 2006 to know when the peak sun is.
3 Powerpoint Slides, Lab of June 3rd
These powerpoint slides (with movies and sounds)
that were given out during the lab of June 3rd.
4 Notes for the lab of of June 10th and beyond
represent material discussed during the lab of June 10th.
The notes also contain the BASIC programs discussed in class.
We will go over these during the lab of June 16th also.
See these figures
that accompany the above notes.
5 Initial Announcements (many ideas / directions were changed)
To sign up, please reply to firstname.lastname@example.org by May 22nd.
Four 2-hour classes as above are being offered to benefit entering 8th
graders (or others interested).
These classes will be held in the Digital Systems Labs of the School of
Computing, University of Utah. Experiments will involve basic electricity,
electronics, interfacing devices with computers,
and some elementary computer programming.
The fees are expected to be around $40, primarily to cover the cost of
hardware. The students will be able to keep their projects.
Planned experiments include:
Space is limited, so contact email@example.com if interested.
The classes are offered by Ganesh Gopalakrishnan, Professor,
School of Computing.
Wind power generation
- Solar power generation
- Control of a stick insect Robot using a computer
- Associated concepts in math, science, and programming will be reinforced.
Parents are invited to the first session to see the labs
and to the last session to see the finished projects.
To sign up, please reply to firstname.lastname@example.org by May 22nd.
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