Tuesday, April 07, 2020

A 'Teaching Instrument' - Experimental Element of Education during Lockdown.

How to ensure that experimental work can continue in such lock down conditions too?

Here is a paper written by Prof. K V Sane, with whom I had an opportunity to work with, during 1989-1992. The solution is, what he calls a 'Teaching Instrument'.

You may have already realized how the specifications of several instruments in electronics labs are way above their actually utilization. A 1GSPS/100 MHz DSO commonly found in electronics labs, hardly ever gets used beyond 1 MHz.

Today, the cheapest 3-1/2 digit DMM sells for less than Rs. 100. It is not impossible to imagine a 10MHz BW DSO front end connected to your laptop (for the display) for Rs. 250. Thus, it is quite possible to imagine a 'Lab in a Box' with a set of components etc, all for less than Rs. 1000 that may be quite sufficient for conducting experiments at home during lockdown conditions.

Getting a student to build such a 'teaching instruments' will generate an additional benefit of student involvement, skills in soldering, system design etc, which are currently sorely lacking.

Monday, April 06, 2020

Parenting an Industry in Engineering Institutes

This is an old idea I thought strongly about in the past, which is making a comeback, at least in my mind. Perhaps, it is the right time to consider it seriously, however crazy it might appear:

"If a medical college must have a hospital to function, why should it not be mandatory for an engineering college to have an industry on campus? For how long would we keep fooling the country that we are engaged in 'blue sky' research? That 'blue sky' research has no term period. Choose an industry of your choice, whatever is needed and beneficial in your region, choose the scale that you can handle. But for your own sake, choose something."

This idea will also address the concern of many academics who often defend the Indian engineering educational institutes and feel they are the victims. However flawed their defense of the Indian engineering educational institutes maybe, this proposal addresses that also.

Also, if you notice, this idea is making a backdoor entry in many engineering institutes in India already - how would you describe the so called 'Incubation Centres' if not a backdoor entry of industry into educational institutes?

However, as currently implemented, the incubation centres are flawed. The engineering colleges which are hosting such incubation centres, do not have their own skin in the game, they are merely working as landlords. They take government's grant money and use their extra space to rent to start ups. That has to stop. The engineering institutes must take larger ownership of these start ups and groom them as their own. And not just to sell off to an established company but to actually manufacture something.

Tuesday, March 24, 2020

Assistive Technologies for Visually Impaired Students

Last week, before the lock down kicked in, I had an opportunity to participate in a week long workshop conducted by Department of Education in Science and Mathematics (DESM) at NCERT. The workshop was about putting together requirements and guidelines for creating assistive technologies for the visually impaired students to visualize and enjoy science in general and to pursue science experiments in particular.

Midway during the workshop, I showed all the participants (around 20 teachers from various levels) all our embedded systems projects many of which demonstrate talking sensor ideas.
As a result, I am happy to share that I have been tasked with creating about 12 assistive sensor projects. They deal with sensing liquid, light, touch, heat, weight, color, pressure etc and to convert to sound and/or speech.

It's not only a great honor for me and my cohorts at NSUT, it is also a great responsibility. It is important that the faith that has been reposed in us, should be responsibly discharged.

I am therefore, using this platform to seek summer interns to work on these projects. I am looking for students with good 'Maker' skills together with knowledge about electronic circuit design and fabrication, embedded controllers, embedded programming and circuit and system fabrication. Please e-mail me your CV/resume as a PDF file that lists matching skill-set at: dvgadreatgmaildotcom.

Caveat Emptor: We don't know how this current pandemic will play out and whether we will have any summer vacations at all. So, please keep that in mind.

Wednesday, October 03, 2018

Posthumous Digital Picture Frame

I read the following on WhatsApp:

जब तक जीवन है ……रोज डी पी बदलिए.

बाद में तो एक ही फोटो में लटके रहना है 😂😂😂

वो भी बच्चों ने लगाई तो !!!😜😜

(While you are alive, change your DP everyday. After you are dead, there will only be a single picture on display and that too if your kids put it up!)

When I think about it, it dawns on me that it is so true! But in this day and age, it need not be like this at all. Here is a possible business idea - A posthumous digital picture frame. You purchase a plan and you start submitting your pictures to this service. Once you die, the people you name in your will, will be delivered a digital picture frame which will have all those pictures you submitted over time and they will be displayed on the picture frame cyclically!

I am very sure this a great idea and may have good demand.

Monday, October 01, 2018


As of 26th September, we are now Netaji Subhas University of Technology!

Earlier last month, on 9th September, we had visited the Centre for Education and Health Research Organization (CEHRO) office at Munirka Village near JNU and interacted with around 40 kids who had assembled to hear me speak and watch the project demonstrations that I conducted. Several of these students sent me a report of the day's activity that they witnessed, in their own words. As a follow up to that event, we invited select students from that group to visit my lab on 30th September.

This blog is a record of their visit. In my opinion, their visit was not only an opportunity to learn about tinkering, science and technology but also about being good citizens, first and foremost.

The CEHRO kids belong to very poor economic background, which is actually a very important and good reason to engage with them. I have interacted with 100s of kids from rich public schools. Kids of these schools already have good facilities available to them. Why not engage with kids with poor economic background and contribute whatever little I can?

Twenty two kids accompanied by four mentors, including Surjeet Singh (our 2012 batch alumni) who runs CEHRO traveled by  DTC bus (number 764) and landed up at NSUT around 11:30 am on Sunday, the 30th September. I managed to catch them just as they were entering the campus.

I stopped them right there and explained them that we are now a University. One kid asked what is the difference? I told them that as a college, we were affiliated to a university, the Delhi University, which had other colleges too. Now since we are a university ourselves, we will eventually have more colleges affiliated to us. So, from college to university is like going from a 'lake to ocean' difference of scale.
As we walked to the CEDT on the 3rd floor, I stopped them at the gate and explained to them the features of the CEDT. I also had an opportunity to turn the staircase lights off (at around 11:30 am), so I explained to them the need to be alert about energy wastage on street lights, staircase lights etc. and do whatever it takes to get the lights switched off or switch them off themselves if they can, in the interest of saving energy. I also pointed them to the 'Twilight Switch' that controls the lighting of the notice board of CEDT right opposite the entrance of CEDT. I explained how sunset/rise time at a given location can differ significantly from another location in the same time zone and how a computer (a normal or an embedded variety) can calculate this time and control street lights etc.
I explained to them the meaning of the name of our lab - CEDT. And how CEDT has been a mother lab, spawning more labs and activities. I highlighted Motherboard, Mothership.. the importance of Mother in our lives.

 Once inside the lab I explained what all activities we would be doing. Since some of the kids did not have any notebooks and/or pens,  I suggested that they go around the campus with Surjeet so he could show his 'alma mater' to them while I arranged for notebooks and pens for them. They came back in 15-20 minutes, ready for the activities.

We started off by showing some projects which we could not show when we had visited their place earlier in September. Also discussed a simple idea about measuring the perimeter of regular shapes as well as irregular shapes using a string. Also, various ideas of measuring larger distances using different methods such as Google maps or more accurately using something called a measuring wheel or a Surveyor's wheel.

I also mentioned about how light, which otherwise travels only in straight lines, can be bent using optical fibres. We showed them a demo of a LED coupled to a plastic fibre and the light coming out of the other end of the fibre, even though the plastic fibre was coiled.

Next, we demonstrated the magnetically levitating doll. And how Maglev trains work by reducing friction. How part of the total energy is dissipated as heat due to friction and accounts for energy loss.

At this point, we distributed the 'mini sadbhavna kit' to the students but before that, I asked them to make groups of 4-5 kids each. A kit would be shared by a group  of these 4-5 kids. Surjeet suggested that they would make the groups but I chimed that let the students themselves make the groups but ensure as much diversity in each group as possible. Since there were older girls, older boys, younger girls and younger boys, each group should have variety. Why is diversity important? Not only because our national slogan is 'unity in diversity', one must experience diversity by trying to understand the view point of others. That is done best by working together.  This breaks down prejudices and at the same time allows one to know more about others, culturally, age and sex wise too.

We left the kids with a set of rules to follow to make the groups and while doing that I noticed that they will probably be discussing things amongst themselves and some kids may keep talking and not listen to others. This I explained, is a big disrespect. Not listening to others, not giving them time and opportunity to talk, there is no bigger disrespect than that. And this is a hallmark of our current social milieu. Many TV debates as well as some debates in the parliament and state legislatures have become prime examples of this lack of personal respect that we (dont) extend to others. This must change. And the discussion around the formation of a team was a good opportunity to learn to respect for others by listening to them without interruptions.

Back to the activities of the 'Mini Sadbhavna Kit', once the kids had made 5 groups. We explained the contents of the kit. The first experiment to perform was the Homopolarmotor. Got them to cut a thin  paper strip to attach to the wood screw used in the motor and explained the importance of the magnet, the polarity of the magnet as well as the battery and to make the motor with all the 4 combinations of the battery polarity and the magnet poles.

Once everyone got the Homopolar motor working, the next project was the DC motor. This time, we simplified the construction of the DC motor and got rid of all soldering requirements. Instead made the DC motor with a pair of metal paper clips, 2 rubber bands to hold the clips to each side of the battery and the magnet stuck to the battery. We explained how to roll the coil using the thick enameled copper wire and how to remove the enamel from the wire and at which places to remove the enamel from. This part took lot of time and many groups attempted the coil a few times before they got it right. I drew lot of sketches on the blackboard as well as demonstrated with actual activity to help with the coil winding. At the end, all groups got their DC motor working and every member of the group had fun making the motor move.

By this time, it was 4 pm and time to wind up. Although the kit had one more experiment (the Faraday's law based demonstration), I thought we should do it at a later date. I reiterated the need on the part of all the participants to write a comprehensive report about the day spent at CEDT and only those who complete this report would be allowed in future activities at CEDT. Here, you can see many participants standing up explaining to others, in their own words, what all should be documented in the reports!

In the end, we all - kids, mentors, our CEDT student mentors, posed for a group photograph before bidding goodbye with a promise to meet again soon!


These are great kids! They all listened and participated with great enthusiasm. They appear to be better students than those I have had from more elite schools. Maybe, their relatively poorer financial background makes them better students compared to students from richer backgrounds! Certainly, the great alacrity with which many of them sent me reports of our visit to their office on 9th September 2018, compels me to believe that.

I wish all these kids a great future together with a promise to help them in any which way I can.

Tuesday, September 25, 2018

So You Want To Build An Electronics Project?

So you want to do an electronics hardware project at CEDT (or your own place)? You are welcome! However, before undertaking a project, it would be prudent to take the following points in consideration at all times during project planning and development.

1. Aim, objective and deliverables: What is the aim of the project? What is expected from it? Writing this down in black and white is important and helps during the execution phase of the project so that one does not veer off the original objectives. The deliverables should include the final project in physical form, any prototypes if they exist (and have not been cannibalized), record of the testing strategy and test data, a comprehensive report with suitable photographs and possibly a video of the working project. One can also estimate the total time it would take to complete the project as well as time for each part of the project. One can map this on a Gantt Chart for checking dependencies between various parts of the project.

2. Visualization: How do you visualize your project. Visualization of the physical form helps in better planning towards the project. Visualization is often helped by drawing sketches, keeping in mind the physical dimensions of the components expected to be used in the system as much as possible. One can also use some CAD tool to help in visualization. Such tools have the added benefit that they let you visualize from various angles.

3. Schematic and PCB layout:
Electronics will remain the most important part of projects at CEDT and therefore it is very important that great care be exercised in the issues related to schematic capture and PCB layout. We use EagleCAD for schematic and PCB layout. We also have a parts library named ?CEDT? although it may need substantial inputs to include new and emerging parts and more activities related to the use of this software so that everyone is competent in creating quality schematics and PCB layouts. The user is expected to create a Bill of Material (BOM) file during the completion of the schematic and layout files. EagleCAD allows the user to export a BOM file and one could create a word document with further details added to the basic BOM file exported from EagleCAD. The PCB layout should have sufficient space for all the components and should have holes for mounting screws in an enclosure. A separate and detailed note on the aspects related to schematic and PCB layout can be referred to, for details.

(Example of a badly drawn)

(Better schematic)

(Example of a good PCB layout. Notice the mounting holes on the four corners)

4. Circuit Fabrication: Any electronics project can be implemented in 4 ways. Each of the methods has their own advantages and disadvantages as listed below:

* Prototype on a breadboard: The breadboard prototypes should normally be avoided. This method allows fastest testing of an idea but suffers from several issues such as connection problems that can compromise the testing and take more time to fix than anticipated. Breadboard testing that involves high impedance or high frequency or low level signals can be very daunting and challenging. One of the challenges of prototyping with this method is the difficulty/inability to use surface mounted devices (SMD) because of the much smaller pitch as well as lack of insertable pins on such components. SMD components do not have pins but pads that cannot be inserted in a breadboard.

* Prototype on a general purpose zeroboard: This is a good way to test your project. However, it can be a challenge to solder SMD components on a zeroboard. Also, use this approach if you plan to just test an idea that cannot be tested with a breadboard approach and you plan to integrate this test circuit in a bigger circuit later on. Or if you plan to build only one single circuit with no plan towards mass duplication. Typically, the general purpose zeroboard also has a pitch of 0.1 inch and that makes use of SMD components as challenging as prototyping with a breadboard.

* Prototype using a PCB made in the lab: This is a standard practise in the lab (although it has been observed that people rush mindlessly in making a PCB only to dump the PCB after fabrication because they discover some flaw in the design). Please refrain from making a PCB for the sake of a PCB. It wastes common resources and creates pollution that can be minimized. Usually, it is very easy to make a single sided PCB but making double sided PCB is not difficult either and usually involves making two single sided PCBs and then sticking them together, taking great care in ensuring that all the holes align properly.

* Prototype using a PCB fabricated through a PCB vendor: This approach is desirable if most of the components are very small feature size SMD components that cannot be soldered on a PCB made in the lab. This approach would take a lot of time and money before the PCB can be tested. Extreme care should be exercised before the PCB files are sent to the manufacturer for fabrication. Once sent, the exercise cannot be undone or aborted midway without a financial and time penalty.

5. Power Supply:
Electronics projects can be a simple circuit that has just one PCB and few components. But even the simplest of electronic circuit will need a power supply. During the testing phase, one may like to use general purpose power supply for testing. During this phase, it is recommended to measure the voltage being applied. It should be ensured that the polarity of the voltage being applied will not damage the circuit. The current consumed by the circuit should be noted. For low power circuits, the current consumption may be less than the least count of the power supply readout or what if the power supply does not have a display? One could use a digital multimeter (DMM) for recording the consumed current but often, the current reading capabilities on a DMM are compromised, then what? There are alternative methods like using a small series resistor together with a DMM to measure voltage across it as a measure of the current, could be used. The choice of this series resistor is critical and care should be exercised in selecting the value and power of the required resistor.

Eventually the project may need it?s own power supply. For the power supply, the source of energy, any step up/down mechanism and the voltage regulator, all these aspects need to be considered. Also, some projects may require non-stop uninterrupted operation and so ˇuse of a standby battery may be needed. All these points must be kept in mind while designing the power supply. One may also rely upon ready-made power banks to power their project. It is imperative to keep in mind that most power banks have an auto turn-off feature if the current being drawn off the power bank falls below some lower threshold and this may turn the project off.

6. Circuit Soldering:
Once the PCBs are ready, you should physically inspect the PCB for any possible shorts or open connections on the PCB tracks. Using a magnifier glass is often helpful. Start by soldering those components that have the lowest physical profile such as SMD components, resistors etc. Make sure that the soldered connections are done properly and do not exhibit any shorts with neighbouring pins. Check for dry solder joints too. Avoid using extra flux, as the solder wire has sufficient flux inside and when you melt the solder wire on the soldering pads, the flux is released to help clean the surface. For extremely dirty contacts, one may need additional flux and if that is the case, one should clean the PCB with suitable solvent after the soldering is completed.

7. System Wiring:
Sometimes, the project will involve connection to the outside world using wires. Such connections need to be made with great care specially the physical stress and strain the wiring will have to bear. It is strongly recommended that the wiring be securely anchored to the physical enclosure (or the PCB) just prior to the electrical connections being made. In the absence of this ˇanchoring, if the wiring experiences external stress and strain, it may lead to electrical short in the circuit.

8. Testing: Testing while the project is in progress is a good idea. You may test connections by visual examination. After all the soldering is completed and if the project allows, one should start by testing the power supply without engaging the rest of the components, specially ICs. This is easily doable in case the ICs are DIP version you have chosen to use a IC socket. If the system uses SMD components, it may not afford this possibility but certainly the supply voltage could be tested before the SMD components are soldered. One should check if the required voltage appear at all the power supply pins of the components and ICs? Check with a DMM and an oscilloscope. The other tests should include the following. Testing does not merely mean taking a reading. It means keep a written record of the readings.
* Measure the supply voltage at important points of the circuit and keep a record of this.
* Measure the quiescent current consumption. In fact, for CMOS circuits, there is a very well known and popular testing protocol referred to as IDDQ testing. Apart from quiescent current, measure the operating current in various states that the project might operate in. When driving motors or inductive loads, the transient currents when the load (motor etc) is switched on/off need to be watched.
* For timed circuits, measure the time using a stopwatch or an oscilloscope depending upon the resolution.
* Measure the frequency of the circuit if there is dominant frequency. For example, many circuits would employ a microcontroller or a Real Time Clock (RTC). Both these components require a crystal (the microcontroller may be working using an internal RC oscillator and it may not be directable readable), then one should record the frequency values.
* If the circuit employs op-amps, one could measure error voltage at the input terminals.
* If the circuit employs an astable multivibrator (using 555 IC or otherwise), measure the frequency.
* If the system uses a Pulse Width Channel (PWM) signal, measure the frequency of the PWM signal and ensure that it is according to circuit and system design requirements. If the circuit employs a signal filter then the filter should be tested independently for proper operation.

9. Enclosures: It may be imperative that your project is housed in an enclosure. Except for very simple projects, most projects should have a suitable enclosure. There are many ways to get a suitable enclosure for your project.
* Find a suitable ready-made enclosure. There are many vendors that sell such enclosures in a variety of sizes and ˇmaterials - plastic, aluminum etc.
* Make an enclosure using PCB stock, by soldering the PCBs together to build the walls etc. Such an enclosure also works great as a Faraday cage. Enclosures made with PCB material may not be very rugged or sturdy and may break easily.
* Use a 3D printer to build a custom enclosure. This approach is very good for prototyping. However, one must be aware of the large time it takes to 3D print anything.
* Make an enclosure using paper or cardboard. This may be acceptable in some situations.
* Build a custom enclosure using traditional materials such as wood, plastic or aluminum for which you must have suitable fabrication and machining tools and skills.
* Use food grade boxes for enclosures. These days a lot of variety of food grade plastic boxes are available quite inexpensively. This may be quite acceptable for prototyping.

Apart from suitable enclosure, one may need to puts text or other identifier markings on the enclosure. This helps identify the various input and output connectors, inputs and outputs. This is extremely important to avoid making wrong connections. One may use permanent markers or use decals transferred on the enclosures for a more professional outlook.

10. Documentation: Creating complete documentation of the project is an extremely important activity. The documentation should include the title, the motivation, the plan that was envisaged to undertake and complete the project. Further, the documentation should include all the technical details such as the block diagrams, electronic circuitry, the PCB layout, the testing protocol that was employed to test the system supplemented with relevant records and ˇpictures. If the project used a microcontroller, the details of the flowchart and the code would help. At the end, suitable references that were used in the project help a lot. Documentation could also include a video of the operation of the project.

Tuesday, July 24, 2018

The Inevitability of Tinkering

In the 80s, when I completed my high school, the only source of information was books – personal or in the library of a school or college. To know about anything, you had to seek access to these books.

Also, the only source of physical material or gadgets or such consumer goods was the corner shop. If you wanted to have something, you would have to find a suitable business that sold it and you could buy it off them. As a consumer in the 80s, the economy was controlled by what is referred to as the ‘license raj’. You could only buy something which local companies with the government license to manufacture things within the country, could sell you. Having access to consumer goods manufactured abroad required you to shell out big money in the ‘grey’ market.

Cut to the 90s and one of the two aspects mentioned above changed drastically. I got employment in a modern S&T institute of India that provided easy Internet access. Now, besides the library, the Internet was an easy and copious source of information at the touch of my finger tips. With the evolution of Internet and subsequent birth of Yahoo, Google and such search engines, access to information grew exponentially. Ideas in one part of the world could flow to you almost overnight.  Those ideas impacted social as well as scientific, academic and every other activity in the country. However having access to information was one thing and having the ability to implement those ideas through physical, tangible things was quite another. Access to tools, implements and material was still regulated and hard to come by.

In the mid 2000s, things started changing such that access to physical objects became easier. Internet banking coupled with Ebay, Flipkart, Amazon and such e-commerce sites, changed things almost overnight. So much so, that majority of well-healed Indians found it easier to shop on the Internet than go to a physical store to fulfill their material needs.

In the second decade of this millennium, the access to Internet as well as Internet assisted material purchasing mechanism has led to something quite dramatic – the democratization of access to information as well as material objects has percolated down to people of all ages specially in schools and colleges. A cookery enthusiast in North India in the 90s would find it near impossible to cook say, the 'Paniyaram', a South Indian delicacy, which requires a special vessel. Today one can fulfill that need over Flipkart/Amazon almost instantly. While we may rue the harmful impact of Facebook and WhatAspp on the lives of young people, an aspect of this ease of access, that is undeniable in importance, is the flow of ideas regarding what a kid of comparable age is doing in countries across the globe! She is not only Facebook’ing or WhatAss’ing, but is also putting the Internet to good use towards enhancing her STEM education. Young people in India are not insulated from such ideas and activities.

Given this scenario, what should our schools and colleges do? They could remain mute spectators to this development and pretend that they are the sole repository of knowledge and scientific skills only to find the rug pulled from under their feet, so to say. Thankfully, the Government of India has shown alacrity in recognizing the growing trend of ‘making’ things on your own and ‘tinkering’ in general. The idea of ‘digital manufacturing’ that is staring in our face will leave us further impoverished unless we wake up to it's potential as well as the threat it poses. Digital manufacturing refers to the concept of transaction of blueprint/design of a product over the Internet assisted by local manufacturing facility that reduces transportation costs and delays and allows people in any corner of the country to have access to material and products of their choice, unlimited and unshackled by the physical distribution mechanisms.

The Government of India has started ‘Atal Tinkering Labs’ in lot of schools (~ 5000 schools as of July 2018) but given the limited resources, it cannot reach each and every young person in the country. But every young person can see what is happening in their more affluent neighborhood and across the world and if she can afford, she would start making things on her own, cocking a snook at the established ‘centres of knowledge’ and reduce them to mere certificate distribution centres.

The inevitability of being useless and redundant is facing our schools and colleges and they better sit up, take note and adapt. The biggest stakeholder of the school and college ecosystem - the teacher is facing a big threat of being sidelined and rendered useless, unless they learn and adapt the new skills of tinkering. It is no longer good enough to be a physics teacher. All the physics you can teach has already been hijacked by the coaching centres in Kota. What is required is a physics teacher who can not  only teach the concepts but can demonstrate them with a physical implementation. This physical demonstration does more to instill the concepts in a young mind than rote learning. If the teacher does not adapt, the young person in your school may not know more than you but with access to the Internet and Internet assisted banking and e-commerce means they can certainly do much more than you do or has ever done.

These Atal Tinkering Labs started in a small number of schools will only grow. The way computers got introduced in schools in the early 90s should give us a clue. From being objects of novelty then to an established subject today, is how the ‘Tinkering and Making’ activities in schools will also grow. I predict that in a few years, 'Tinkering' will become as mainstream a subject as computer science in schools. How do we want to use them? How do we want our young children to use them? Currently, the Atal Tinkering Labs, without much mentoring support, finds itself with students copying projects off the Internet, the teachers being clueless about state of the technology feel their students have just invented something! While one may frown upon this practice, the fact is at least these students are getting exposed to working with their own hands - a very welcome development in this country!

Eventually, one hopes that the real objective of the Tinkering Labs which should be to enhance science learning, will be understood. That will help absorb 'Tinkering' as a necessary skill/subject in each and every school and that alone has the potential to invent new solutions to solve problems of the Darbhangas and Mumbais of India - deaths due to manual cleaning of sewage drains, farm problems and distress, lack of clean drinking water, roads and flyovers taking years to complete.

The inevitability of tinkering and making things on our own, is surely staring at us and we better prepare now or become complacent, ignore and eventually become redundant – the choice is ours!

Update: This blog is now published on Swarajya Magazine: Tinkering Labs: Why Schools Must Sit Up And Take Note