STEM land Inauguration

We inaugurated the STEM land on 9th October 2015. It was one of my awesome moment in my life. I learnt a lot in that period( like organizing the materials, maintaining the STEM books, planning for inauguration and 3D printing).

STEM land inauguration started with lighting ‘floating candles’ followed by small speech on STEM.


Isai Ambalam & Udavi school students were put stalls on Robots, Puzzles, Strategy games, ,  Measurement equipments, 3D printer, Fraction kits, Scratch programming  & Arduino  programming. “Well beginning is half done“.





The Hindu article about the STEMLAND

Making, tinkering and engineering their way to knowledge

School uses theory of constructivism, which says knowledge is not taught to a learner

At the STEM (Science Technology Engineering Mathematics) Land and Resource Centre at Udavi School in Auroville, young Hemasundar is busy tinkering with the robot he has made using a kit. “We can make different robots with different functionalities . I have picked up some programming with this, and how to give different commands for the robot,” he says.

The class-VII boy dreams of becoming an archaeologisit, he says, and wants to design a robot which can used at excavation sites. His friend Vignesh adds that he wants to become a scientist, and make a robot that can help in astronomy.

The STEM Land and Resource Centre that was inaugurated on Friday has been created by Aura Auro Design (a technology unit in Auroville) and is a project of SAIIER (Sri Aurobindo International Institute of Educational Research). It is supported by the Bengaluru based comapany, Aura Semiconductor.

Heading the initiative is Sanjeev Ranganathan, who has worked at Silicon Labs, NXP, ST-Ericsson and volunteered with Asha for Education and worked on innovative education projects with them. For the last two and half years, Mr. Ranganathan has been in Auroville and teaching Isai Ambalam School. On his team are Vaidegi G., Sundranandhan K. and Bala Anand.

STEM Land and Resource Centre takes from the theory of Constructivism, which implies that knowledge is not taught to a learner but recreated by the learner on his or her own. It encourages learning by doing and discovery learning.

“When you build something outside your knowledge, you learn something better. At STEM, the learning is through the ‘Making, Tinkering, and Engineering’ concept. The idea is to make the child understand the principle and give her the ability to predict a situation. They are equipped with implicit knowledge that can be applied to different situations,” says Mr. Ranganathan. While the centre primarily targets children between class VI and IX, the resource centre is also for adults to experiment and create at its ‘maker space.’

With a material room and a building room, it is equipped with 150 puzzles and strategy games, apart from variety of learning materials in maths and science. The students get to use the Arduino technology, an Open-source electronic prototyping platform to create interactive electronic objects.

Maniyammai, a system engineer with Saracon in Auroville, is one of the adults who have come to interact with the students and learn in the process.

“The children learn programming and coding. It is good to come here and share our knowledge,” she says.

The center has come about with help of several youngsters in and around Auroville, like Arun who is working on an oscillator circuit that can be used in radios, and audio and video signalling.

Education today

Mr. Ranganathan says the present education system has oversimplified learning where undergraduates have to be trained from scratch. “The purpose of education has been narrowed down to just getting a job,” he says.

Education must be geared towards not just fitting in, but also standing out, he says. And in Auroville, education is also about figuring out what one wants to do, he adds.

The purpose of education should not be about just getting a job”

Sanjeev Ranganathan, teacher, Udavi School and Isai Ambalam School

Dated: 10-10-2015


Getting ‘officially’ started in STEMLAND

The inauguration of STEMland has just happened. It feels good to be part of something different and useful for children as well as adults who are into math, technology, electronics etc… Over the past month and a half STEMland has given me the space and opportunity to learn and grow with the children. This process of learning(peer learning) in STEMland will always grow as I think there is enough scope there. This place should get well used and benefit everyone related to STEMland!

Timer in Python

I encountered a situation where I had to check if a function is running for a certain time. The below method called ‘after’ was very useful. This registers an alarm callback that is called after a given time.

Syntax : after(delay_ms, callback=None, *args) 

Creating a Spice Model from a .subckt file

The following video demonstrates on how to create a spice model of a component, from a .subckt file which can be acquired from the retailer.

following is a spice model file for a bridge rectifier ; mb6s

data sheet : MB6S_MCC

– Open LtSpice

– Browse for the file and open

– Once opened right click .subckt and create model and design your circuit.

-Ref :

Op-Amp positive feedback design

The following circuit has a voltage source that operates between 3V and 5V and is connected to the Op Amp’s positive input, across a resistor divider R2 and R1 at the node Va. The simulation is run for 200m secs.


The design is as following: applying super position










Following is the Spice file :  opamp_gnd

Video :Positive Feedback







Science Technology Engineering and Mathematics (STEM):

STEM Land:

STEM Land  is a place for ‘Learning’ which we are creating in Udavi school. The vision behind the STEM is learning based on Concepts, practical observation & abstraction. In short “Mediocrity to Excellence“.

It has large variety of materials ( Robot, Physics based materials & kits, Demonstration models, Electronic components & tools, variety of Measurement Equipments, Montessori & Jodo Gyan materials, Strategy games, Puzzles and Books). So we can engage all the students based on their capacity level without letting them feel overburdened  or bored. Most of the students get enthusiastic and become active learners when they get into a new environment ( where the usual text books are absent). So it is added advantage of STEM.







This three students (7th Grade) have assembled the Robot parts (nearly 300 small pieces). They also programmed the Robot for a challenge I set for them (with guidance). Here they learnt how to be systematic (while assembling the parts of Robot). And became programmers when they started to  program the Robot.








This student is an example of perseverance. Many people gave up when they were trying to solve this square puzzle (including me).  One of the reasons was, we got bored. But he pursued  till he reach it. Our curriculum needs this type of activities to empower students to use their creativity to solve problems, ask questions and continually learn.


Students  need to be challenged. At the same time not  be bored. I hope strategy games are one of them which satisfy this condition.  And this made them think and observe keenly without supervision.

LtSpice – Introduction

LTspice IV is a high performance SPICE simulator, schematic capture and waveform viewer with enhancements and models.

The simulator software can be downloaded from the following link:

The following is a circuit on how to use a switch ” .model ” in simulations, it has been created for a RC circuit.sw

As seen these switches are not a physical model, they require a initial voltage to start to act as one.

20150820_switch_RC is the simulation file for the given circuit, can be seen by installing LtSpice.



Every switch has some instance of resistance when on or off;
Ron = 1            ‘ the resistance when the switch is turned on.’
Roff = 10meg   ‘ the resistance when the switch is turned off.’
Vt    = 0.1         ‘ the instance when the switch turns on’

Classical way to solve the RC filter in time domain :

RC filter classical time domain way