The Confederation of Indian Industry (CII) works to create and sustain an environment conducive to the growth of the industry in India, partnering with industry and government alike through advisory and consultative processes. CII Puducherry Innovation Contest organized in partnership with Atal Incubation Centre, Pondicherry Engineering College Foundation is an ideal platform for the Students and Startupreneurs of Puducherry to showcase their innovative ideas, proof of concept, and prototypes. The event is structured through a 3-stage process that involves application shortlisting, online presentations, and a Pitch round. Boot camps, personal mentoring by Industrialists, and guidance by AIC are the salient features of the contest. Winners of the contest will get an opportunity to take their ideas to next level in the Atal Incubation Centre, PECF, and an opportunity to avail of seed funding.

The energetic youths of STEMland Vikinesh. R, Mugilan.M, and Punithavel.M from the Acharya College of Engineering and technology as the team participated in CII Puducherry Innovation Contest 2022 and presented their project “SALTWATER LAMP” and got selected for the finals of the Pitch round. They worked on this project to address the problems encountered by the fishermen and the public during disasters.

From left, Vikinesh. R, Mugilan.M, and Punithavel.M.

First, they conducted a survey to formulate the objective and worked on a solution – saltwater lamps. They used the STEMland tinkering lab to develop this project. This project paved the way to help fishermen during the night-time, deep sea fishing, and the public during disasters. The project employed salt water to produce electricity through which the lamp glows. The team presented the project to the C3streamland team to have a final rehearsal before presenting in the contest and took feedback for growth.

The project set out to be a benchmark and inspired many rural youths to use the STEMland tinkering lab for developing projects.

Ambient light sensor using a photoresistor and Arduino Uno

This project is about using a photoresistor along with an Arduino Uno board to determine the brightness of a room which is bright or average light or dark. A photoresistor which is also called an LDR (LIGHT DEPENDENT RESISTOR) and two LEDs and Breadboard and a 1 k ohm Resistor and 2 resistors for the LEDs which range from 100 ohms to 220 ohms are used. The jumper wires are used to connect Arduino digital pins to the breadboard. The output is displayed through the LEDs and Serial Monitor.

WIRING: The photoresistor is wired into analog pin 0 and a 5V on the right side of the breadboard. It runs through a grounded 1K ohm resistor. An LED on the opposite side of the breadboard into digital pin 13 and grounded a 220-ohm resistor slightly to the right of the first LED, a wired LED of a different color is employed, just with a different digital pin.

Photoresistor working principle:

A photocell or photoresistor is a sensor that changes its resistance when light shines on it. The resistance generated varies depending on the light striking the surface. High intensity of light incident on the surface will cause a lower resistance, whereas a lower intensity of light will cause higher resistance.

WORKING: If the photoresistor reads a value above 450 ohms, it prints “It is quite light!” on the serial monitor and turns all LEDs off. If it reads a value between 230 ohms and 450 ohms, it prints “It is average light!” on the serial monitor and turns on the left LED. This only leaves us with values below 230 ohms to account for. If a value is below 230 ohms, it prints “It is quite dark!” on the serial monitor and turns on both LEDs.

Components setup:


The ambient light sensor is used to control the backlight of LCD-based applications to control the display brightness of mobile for reducing battery life. The applications of this sensor range from consumer electronics to automotive. This is the main benefit of mobile applications.

These devices are used to replicate the sensitivity arc of the person’s eye, allowing mobile displays and the levels of its brightness to be attuned more accurately. These sensors are used in automotive applications like headlight control & cockpit dimming.

The main feature of this sensor is an automatic alteration to save power & to increase the LCD screen’s life in handy display devices. Additionally, these sensors control the backlighting based on the program set by the maker.

This sensor is also used in indoor as well as outdoor lighting for turning on/off which includes street lighting and electronic signals.

LDR photoresistor code

Smart dustbin using Arduino

The smart dustbin is built on a microcontroller-based platform Arduino Uno board which is interfaced with the Servo motor and ultrasonic sensor. An ultrasonic sensor is placed at the top of the dustbin which will measure the stature of the dustbin. The threshold stature is set at a particular level. Arduino will be programmed in such a way that when someone will come in front of the dustbin the servo motor will come into action and open the lid for the person to put the waste material into the dustbin. The lid of the dustbin will automatically open itself upon the detection of a human hand.

Servo Motor:

SERVO MOTOR is an electromechanical device that produces torque and velocity based on supplied current and voltage. It can push or rotate an object with great precision. Servo Motor SG-90 is used. It will perform its angular rotations when a signal will be provided by the microcontroller. The servo motor rotates approximately 180 degrees (90 in each direction).

Infrared sensor:

IR SENSOR is a radiation-sensitive optoelectronic component with spectral sensitivity in the infrared wavelength. It is used for object detection.

Connections: –

The Red Pin of the Servo Motor is connected to Arduino 3.3v. The Black Pin of the Servo Motor is connected to Arduino GND (Ground). The Orange Pin of the Servo Motor with Arduino Pin 8. VCC of the sensor is connected with Arduino 5v.

The Smart Dustbin as you can see in the picture above is built using Cardboard. This is a custom-made Smart Dustbin equipped with HC-SR04  Sensor, Arduino, and a Servo Motor. It is programmed using the Arduino code.


Servo myservo;
int angle = 0;
int angle step= 50;

void setup(){
void loop() {
if(digitalRead(2) == HIGH){

Once there is no one in front of the  Sensor the Smart Dustbin Lid remains closed.

The smart dustbin is a carefully designed solution that solves the social issue of waste disposal.


Sri Aurobindo 150th celebration talks with Aurovilians: Sanjeev

As part of the 150th Sri Aurobindo’s birth Anniversary, On the 24th of August 2022, Dr.Sanjeev Ranganathan had a live talk with the Aurovillians in Savitri Bhavan.

Dr. Sanjeev Ranganathan is the executive of the Isai Ambalam school, Sri Aurobindo International Institute of Educational Research (SAIIER), and RTL Academy. He received his Ph.D. in Electronics from Columbia University in New York City. He is motivated by his growth as a human being and supports the same in others.

Sanjeev is the recipient of the Lewis Winner award for best paper at ISSCC. He also volunteered for Asha for Education in various capacities and interacted with over 100 NGOs in India working on education. He has worked at Silicon Labs, NXP, ST-Ericsson, and Aura Semiconductor and has built chips used by over a billion people.

He addressed the Aurovillians with his inspiring talk by quoting his life instances with the guidance of Mother and Sri Aurobindo. While volunteering for Asha for Education he perceived Education’s purpose is not to just fit in something but also about standing out. It brought him to Auroville in 2000. He started working on alternative education. He focused on how are we going to support the next generation to do something unique.

He organized education conferences to have accelerated learning. He wanted to create a place for people to learn, experience, and contribute. He explored tribal villages and he did Vipassana, a 10-day silent meditative course that gave him a great feel about the right things to do. He also had a spiritual experience while doing his meditation and saw every being connected. All of us are connected. Once we stop judging people, life becomes easy and amazing.

Sanjeev is passionate about developing critical thinking skills with children and helping them learn and connect with their deepest selves. He believes that this can be achieved by deep meaningful educational experiences for both facilitators and children in the schools, at STEM Science Technology Engineering Mathematics centers, and Aura Auro Design, a technology business he coordinates. In time he created Aura Auro/STEM Land that allows youth to learn, grow, work, and teach as a research project and then a sub-unit of SAIIER.

He always followed the ideologies of Mother and Sri Aurobindo in his endeavors. At Auroville he was introduced to Radical Transformational Leadership which has tools, templates and distinctions used to create whole systems transformational solutions. These tools helped him explore what the root of his existence was and how he need to let it synthesize his life to let it manifest.

With the guidance of Mother and Sri Aurobindo, he continues to progress and help others progress in the beautiful journey of life.


A basic gate is defined as a component with one or more inputs and one output.  The inputs and outputs are all digital.

There are three fundamental gates and a total of seven basic logic gates (plus several derivatives). The gate will set its output to either zero or one, based on the state of the input signals.  It uses the rules of Boolean algebra to determine the output condition. The relationship between the input and output logic levels on a gate can be best illustrated using what is known as a truth table.

Simulating Gates with an Arduino:

All of the Boolean algebra functions performed by the basic logic gates can also be emulated on an Arduino. With that in mind, a logic gate emulator that will emulate six of the seven basic gates has been constructed. It doesn’t include the NOT gate because it only has one input whereas the other gates have two.

Project on logic gates using Arduino Uno board consists of 8 LEDs and 8 resistors for the LEDs and two resistors for the pushbutton switches. The LEDs are connected for the logical output and the pushbutton switches are used for the logical input. The positive terminals of the LEDs are connected to the respective terminals of the Arduino board. The negative terminals are connected to the ground of the Arduino.

The green LEDs are for the logic outputs and the red LEDs are for the input.

The dropping resistors for the LEDs are all 220 ohms.

The two pulldown resistors for the pushbutton switches are 2.2k each.

First, define some Boolean variables to represent the logic states of both the two inputs and six outputs. Next, define some integers to represent the connections to the Arduino from the LEDs and push buttons.

It displays logic states on the serial monitor, so in the Setup routine, initialize the monitor at 9600 bps. The rest of the Setup is used to define the LEDs as outputs and pushbuttons as inputs.

In the Loop, it starts by reading the state of the two pushbuttons, and then displaying the results on the two Red LEDs marked “A” and “B”.

The actual Boolean math consists of the following four characters:

  • NOT =!
  • AND = &
  • OR = |
  • XOR = ^

We use the NOT function (!) to create the NOR, NAND, and XNOR gates.

After determining the Boolean results they are sent to both the serial monitor and the LEDs.  Following a short delay the whole Loop repeats.

Load the sketch and give it a try. Cycle through all four combinations of the two pushbuttons and observe the LED statuses, as well as the status on the serial monitor.

This would be a great training tool for testing our knowledge of digital logic.

Arduino gates using code

A session about the life of Sri Aurobindo

As part of the 150th Sri Aurobindo’s Anniversary, On the 4th of August 2022, Smt. Sundaravalli, an ardent devotee of Mother and Sri Aurobindo lives in Chennai along with her friend Vijayalakshmi visited STEMland and had a session with STEM teachers.

She came to Aurlvazhi school in 2002. Shamala and Vardharajan had invited her to translate a few Mother’s books in Tamil. She had worked for Savitri Bhavan at the ‘Pratana Magazine’ as an editor for 5 years. She was involved in Isai Ambalam School activities and workshops and improved her academic skills. She had written a story in Tamil “Illarathil Thuravaram” about The Mother and Sri Aurobindo. She has written the “Life Divine ” with the Grace of Mother and is being published in Auro Mira Centre at Karaikudi. She had done many consecration workshops for children in Karaikudi.

She conducted a one-hour session about Sri Aurobindo’s Life events. She also enlightened the teachers with the five dreams of Sri Aurobindo.

Reflection 1:

The session was energizing and enlightening. The life events of Sri Aurobindo had a huge impact on us. Few sessions in his life events of him were very interesting.

Reflection 2:

Even though he went to jail, he had a desire to achieve what he wanted. So he achieved it. Same way if I have a desire if I work hard I can achieve it in any instance.

Reflection 3:

The pain and suffering that I go through will not make me feel down when my thoughts are bigger.

Reflection 4:

I should focus on progress even if we face difficulties taking negatives as positives.

Reflection 5:

Sri Aurobindo’s perseverance impacted me a lot and made me work on that quality in me. It incorporated the quality of taking difficulties as positives and working on them.

Reflection 6:

I learned to act selflessly after hearing the life events of Sri Aurobindo.

Reflection 7:

His self–belief amazed me and that helped me revive my self-belief and I started implementing myself.

Reflection 8:

What I learned from his life history is perseverance in achieving things, and care for humanity.

Reflection 9:

I learned in being spiritual paves a way to progress throughout life.

A session with Last School Children

On the 28th of July, the STEM Land team visited Last School for a session with them. The facilitating team Prabhaharan, Arun, and Illamkathir along with the last school children worked on RTL tools, seven segment displays, Cast puzzles, and the homopolar motor.

The session started with a few minutes of meditation. The team started the session with the Radical transformational leadership tool that helped children identify the universal values they stand for. Then the team helped the children identify their socialized fears and how courage is not the absence of fear, but the ability to act despite fear.

Later, we learned about the Seven segment Display and its primary uses. Our team explained how to use a multimeter and analyze the SSD and showed a demo. With that reference, the children worked on it and completed it.

Later, the working of the homopolar motor was demonstrated to the children. A Homopolar motor is one of the simplest motors built because it uses direct current to power the motor in one direction. The magnet’s magnetic field pushes up towards the battery and the current that flows from the battery travels perpendicular to the magnetic field. Students had a great time making it.

The whole session was engaging, encouraging, and enlightening. It was a great learning for everyone and we thoroughly enjoyed working with them.

Students from Last School requested to come to STEM Land on Saturdays to learn programming like Scratch and Python.  We will start such sessions soon.

SET Theory Game

A set is a collection of objects or groups of objects. These objects are often called elements or members of a set. For example, a set of all squares.

A set can be understood playfully using a set game that constitutes 3 components. The three components are

  • Colour
  • Shape
  • Size

It comprises:

Colour: Blue, yellow and green

Shape: Square, triangle, and circle

Size: small, medium, and large.

In total, there are 27 pieces which include

9 triangles (x3 colours, x3 shapes):

The three blue triangles are small, medium, and large.

The three yellow triangles are small, medium, and large.

The three green triangles are small, medium, and large.

9 squares (x3 colours, x3 shapes):

The three small blue squares, medium, and large.

The three small yellow squares, medium, and large.

The three small green squares, medium, and large.

9 circles (x3 colours, x3 shapes):

The three blue circles are small, medium, and large.

The three yellow circles are small, medium, and large.

The three green circles are small, medium, and large.

This set game can be used by children for a better understanding of set theory concepts.

Set Operations:

The four important set operations that can be performed using this set game are:

  • Union of sets
  • Intersection of sets
  • Complement of sets
  • Difference of sets

Union of sets:

The union of two sets is a set containing all elements that are in A or B (possibly both). The union of sets can be denoted using the symbol ‘U’. Symbolically, we can represent the union of A and B as A U B.

For example, A = Set of blue colour triangles and B = a Set of Green colour triangles.

Then the union will be all the triangles which are in blue and green.


The intersection of sets:

The intersection of two sets A and B is the set of all those elements which are common to both A and B. The intersection of sets can be denoted using the symbol ‘∩’. Symbolically, we can represent the intersection of A and B as A ∩ B.

For example, A = Set of blue colour objects and B = a Set of all triangles.

Then the intersection will be the triangles which are in blue.


Compliment of sets:

The complement of set A is defined as a set that contains the elements present in the universal set but not in set A. The complement of set A can be denoted using the symbol A’.

For example, A = Set of blue colour circles and U = Set of all circles

Then the complement of A, A’ will be circles which are in yellow and green.

Difference of sets:

The difference between sets A and B in this order is the set of elements which belong to A but not to B. Symbolically, we write A – B and read as “ A minus B”.

For example, A = Set of all green colour objects and B = Set of all squares.

Then the difference between A and B, A-B will be set of all green colour objects except squares.

Fundamental Properties of Set operations that can be observed:

The operations such as union and intersection in set theory obey the properties of associativity and commutativity. Also, the intersection of sets distributes over the union of sets.

Similarly, the set theory game can be used for understanding three sets and their operations.


On the 14th of July students from the Last school, Auroville visited STEMLAND. The forty students accompanied by the teachers enjoyed their afternoon session by exploring STEMLAND.

The arrangements were done by the STEMLAND team. There were 8 stalls which include

  1. Mindstorms
  2. Games and puzzles
  3. Science projects
  4. Makey-Makey
  5. Arduino
  6. Electronics
  7. Scratch programming
  8. 3-D printing.


Mindstorms is a hardware and software structure that develops programmable robots based on Lego building blocks. Each version includes computer Lego bricks, a set of modular sensors and motors, and Lego parts from the Technic line to create the mechanical systems. The system is controlled by the Lego bricks.

Games and puzzles:

Logic and strategy games were present. They include Abalone, Gobblet, Quads magnetic, Aadu Puli (Puli Meka), Linja, Quarto, Quoridor, Othello and Eternals were put on view to play. Puzzles like Rubik’s cube, Cast puzzles, and holograms were displayed to solve and play with.

Science Projects:

Science projects based on concepts were exhibited. The exhibits include

  • Magnetic levitation
  • Electromagnetism
  • Acid-base indicator
  • Dc electric motor model
  • Crank’s model
  • Lungs- diaphragm model
  • Magnetism- properties.
  • DIY microscope
  • DIY headphone
  • Series and parallel connection
  • Lights color – arithmetic model.

These models were made using the Arvind Gupta toys which are made of scrap materials.

Makey – Makey:

Makey Makey is an invention kit by the MIT media lab. With Makey Makey, everyday objects are transformed into touchpads empowering students to interact with computers as creative tools. The computer becomes an extension of their creativity, fostering imaginative play and discovery.

“Makey Makey” is a play on words – students having the ability to Make their Keyboards (“Ma-Key”). The mundane and boring keyboard is replaced by any object that conducts electricity – pie pans, Play-Doh, bananas, and even potted plants – the list goes on.

The projects can be coded by scratch and use the Makey Makey kit as a joystick controller.


Arduino is an open-source hardware and software that can be used for designs. It is a microcontroller and microcontroller kit for building digital devices. It can be programmed and built using the Arduino software. Exhibits include a Distance measurement kit, Automated street light was displayed.


The field of electronics is a branch of physics and electrical engineering that deals with the emission, behavior, and effects of electrons using electronic devices. Projects like Automatic street light controller and automated sound sensor control model, Automatic dustbin were displayed.

Scratch programming:

Scratch is a visual programming language that allows students to create their own interactive stories, games, and animations. As students design Scratch projects, they learn to think creatively, reason systematically, and work collaboratively.

3-D printing:

A machine allows the creation of a physical object from a three-dimensional digital model, typically by laying down many thin layers of a material in succession. The models are designed using software called Tinkercad and converted to the printing g code to feed to the machine using Ultimaker CURA software. This paves for creative models.

The visit session was facilitated by Dr.Sanjeev Ranganathan and the team of STEMLAND. The session started with a few minutes of concentration meditation and a few words about what we stand for, a casual talk on the similarities and differences between the last school and STEMLAND. Students had to choose any two stalls they can spend time on. Some of them wanted to explore all the activities.

Students and facilitators had a great time exploring. Few of them made hands-on projects using the kits provided. They played strategic games and got fascinated by them. It was a pleasure to have them in STEMLAND. The team had wonderful learning, growth, and fun having them.

BHARATHA TIRTHA II- International conference on Indian knowledge systems by IIT Kharagpur.

BHARATHA TIRTHA II- International conference on Indian knowledge systems was organized by IIT Kharagpur. Dr. Sanjeev Ranganathan, founder of STEMLAND was invited to present and he presented on the topic of Rajju ganit (string geometry, cord geometry).

He demonstrated briefly the concept of squaring the circle can be done using the Rajju ganit method. Using the rope, a circle, and a square of the same area can be constructed and observed.

There are two main new features:

(1) The cord replaces the entire compass box.

(2) Empirical methods are admitted in geometry contrary to the philosophy of formal math and using instead the philosophy of approximation.

Some other interesting topics that were presented at the conference were trigonometry in Ancient India and how that led to many discoveries and applications.

Jyotpatti: Trignometry in India

Trigonometry in India is called Jyotpatti.” Ja” means chord in a circle and “Jia” means string in a bow. Mathematicians used this to find the relation between the arc of a circle and the chord of a circle. The sine function is ubiquitous in all disciplines. It is very important to study the application part of sine and cosine functions.

Bhaskara’s metaphor for sine and cosine:

Bhaskar Acharya is a 12th-century astronomer and mathematician. He brought in the importance of science in astronomy, and the application of it is beautifully brought out with a nice simile.

He says that,

Just as fabric(pata)is made up of crisscrossed threads Likewise the spherics or science of astronomy is crisscrossed with sine and cosine functions.

Sines and cosines are everywhere in astronomy:

Interestingly, sines and cosines from the earliest times were formally a part of astronomy rather than a separate discipline of mathematics, it is because applications in astronomy fall all over the place.

The main phenomenal applications such as

  1. Ascensional differences between planets. (Spherical trigonometry)
  2. Epicyclic orbital corrections to planetary longitudes.
  3. Zenith distances and the length of the shadows.

Arcs and chords: The origins of trigonometry in India:

In the 17th century, a famous mathematician named Nityananda Sarvasisiddhantaraja explicitly links the advantage of looking at half chords.

Mathematicians paid more attention to what a chord concerning a given arc is, What is half of the chord of double the arc, and the right-angled triangle which is used for mathematics and computes various line segments concerning half of the chord made computations much easier for astronomers.

Technical terminology introduced bow and bow string:


The evolution of trigonometry in India:

Practitioners needed to compute:

  1. Half chords and other line segments in right triangles using the geometry of polygons inscribed in a circle.
  2. Tables of Rsines are computed for various values of R.
  3. Linear(or occasionally second-order) interpolation is used to determine non-tabulated values.

Addressing these led to brilliant discoveries and the results from the middle.

Mathematicians like Brahmagupta, Aryabhatta, and Varahamihra have given the tables of sine and their geometric dimensions of it.