CoffeeBreak Tutorial #3:The Easy Peasy Stepper Driver/Stepper Motor Test Circuit


Stepper motors are quite widely used for CNCs/3D Printers or other Electromechanical hacks like the polar plotter etc. ! There is as always a constant need to run the motor to check whether its aligned properly or not? Does the flex coupling has any issues? Is the driver dead or alive and the best one- whether the current setting is fine to generate enough torque to hold or move the lead screw.

Pestered by the same above questions i wanted to build my own driver/motor tester overnight and it ‘must’ be microcontroller-less since there is no actual use of a controller here! I stumbled open this awesome project that i saw on Hack-A-Day.

It uses an ATiny AVR microcontroller which is (no offence to the author) an over-kill as most modern stepper drivers like the ones from polulu  need just two signal i.e STEP and DIR.

A pulse on step pin will initiate a step to the internal indexer that handles what coil has to be energized based on the sequence and micro-stepping settings, while the DIR is a level signal whose level decides whether the internal indexer of the driver counts up or down!

So, only two inputs i.e Pulsed input for STEP and level input for DIR. This can be achieved using the 555 timer in the astable mode. The Output of 555 i.e pin 3 will go into the step pin and the DIR pin is pulled up using a resistor and it is also connected to ground via switch.

This gets the job done! We can also have a POT to vary the frequency since some motors dont respond to faster pulses due to rotor inertia.The driver i am using is based on DRV8825 from TI. It is slightly wider than the polulu one. (You might call me a TI fan boy 🙂 )

With the designing almost final , I grabbed a piece of perfboard since, i didnt had the time to etch the board.

The circuit is as follows:


It has two power inputs 12v, 5v and a common ground, all of which are sourced from an ATX! The circuit itself is pretty simple.

The final build on a 8mm perfboard is shown below.



I chose to use a SMD 0603 10K resistor between pin 8 and 7 to reduce the space and connected 104 (0.1uF) Ceramic caps as shown. The switch is a 10xx and the capacitor is required at the input of stepper driver to reduce supply dips when it draws current. I have used female headers for the motor since most motors come with a connector that can be easily wired up with a single strand wire. I used the Power Terminal connectors for the main 12V Driver supply as the driver is rated for 2.5A which is too high for the usual jumper cables !

top and bottom

TIP: If you are using the non-tinned/less tinned headers that have been lying around in the component box for a while, make sure to rub the connectors using sandpaper to remove corrosion residue on the contacts else it might seem soldered but it wont actually be soldered. Also you may use some extra flux.


Cheers !

Rohit Gupta

Travelogue: Ahemdabad Che!


Gujrati Food.. Umm .If you love gujrati food in which ever part of the country you are and then go and visit Ahmadabad for some reason and eat those “Jalebi, Fafda” or Khandvi, I bet your entire “Gujrati Food here(at your place) is good” notion will be changed and you will abstain from eating Gujju Food anywhere else. It has been Months and i haven’t eaten my favorite Khandvi. Its also so pirated here in Delhi. Well.. Food Piracy !

In this travelogue I will go through my adventurous journey into the food and people of Amdavad (as they say there). We were recently there for MakerFest  and in whatever time we got I and my group consisting Of Ishan and Saral sneaked into the city to explore be it late night (1am-ish) or early morning! What i am going to illustrate was done in bits and pieces , but surprisingly can be done in one full day! So, the below log can be done chronologically but was done in 2 days due to other important tasks 🙂

We were based out of Nehru Nagar. So most delicious shops were located nearby. If you plan to roam around next day, try eating something light in dinner as the next day will be “Heavy” .

We woke a early( well 10:30am it was i guess) and reached the famous ‘Juna Sherbazaarwalla‘ for his jalebi fafda combo. Fafda is made out of besan and is usually eaten with green chillis. But imagine if you combine the three. Its an atomic combination, Sweet, salty and spicy -3S ! We saw a local person, on the road sitting on his 80’s Lambeda Scooter and savoring Kadhi also along with 3S’s . So we ordered it too. And it added more ammo to the stuff. Kadhi was a bit sweeter and less salty. We ended up ordering Dhokla too.

Best Jalebi in town
Yum!The best algo is Jalebi in one hand and fafda in another and then dip fafda in kadhi and eat the jalebi first and then fafda. Loop until you drop!

I dont like spices a lot. So, i avoided the chillis. Ishan loved it and posed for it.

Bas kar!


I browsed the shop and found some other interesting stuff as well. Jee Lalchaye Raha na jaye
Make that 4

Ji Lalchahe Raha na jaye!


They were basically all dhokla’s and Samosa but a bit sweeter and nice. Not to say we tasted them as well. We were fortunate enough to be in Gujrat at the time of Uttaran which is when you can get the famous Undio (Dish) and see Gujrat in its full colors.

Round 3

Next we moved to The Khaman Shop! On the same road as Juna Sharebazaar walla , but a little further. Khaman is similar to Dhokla. But I couldn’t understand whats the difference.

The Khaman Shop


The Undio is basically a very spicy but tasty vegetable dish. It contains a lot of oil (I dont know why). But it was very tasty. It had Potatoes,Coriander and lot of other veggies i dont remember. Avoid this is you hate Oil and Chilly.
UndioThen we had the Khaman. It was just Awwwwesome! There was a nice tinge of garlic and sweetness i haven’t noticed anywhere. There is also a female version of Khaman called Khamani. Its a bit more crunchy and Spicy.It has tasty besan bhujia sprinkled over it and served with yellow chutney. Yummy..

Khaman Dhokla

Khaman Dhokla



PS: Just before you start suspecting me of over-eating. This was eaten by a group of 3 😛

With our input buffer almost full. We couldn’t order full plates of stuff we saw in the shop and were happily obliged by the shop owner who gave us some taste samples!

Taste Samples- Dhokla,Khandvi and Barfi Dhokla

Yellow- Khandvi, White-Green- Dhokla, White-Barfi Dhokla

The shop has almost 20 Different types of Dhoklas. Wow!

Since, our stomachs needed some rest. We needed to sneak out to some place of fun and walk.We headed on to Kankaria Lake. As always, prefer Local BRTS which is quite an efficient way to go around the city. Public Transport is always better.

Kankaria LakeThe lake is a pretty huge one, with a lot of things around it like Toy Train around the circumference, Fish Museum , Eating Stalls,Speed Boating, A Hot Air Balloon Ride,Kids in plastic balls that dont sink ( I dont know what its called 🙂 ) and a ATV track with Polaris quads meant for kids below 12 ( :/ )

Train Ride was pretty good. Good ‘ol Days as kids were revisited. Beware the Train Driver can yell at you if you get off the running train.It doesnt go over 12kmph.So, we did got over at Fish Museum. Hahaha.. DONT TRY THIS!

The Fish Museum  was pretty nice. Its a two floor museum with lots of different fishes on display.I dont eat fishes (Vegetarian) and don’t know many fish names other than Piranha ( Piranha 3D 😛 ) , gold fish ( Childhood stories), Sharks (Jaws) and Turtles. All of them were present there. Happy to meet you in person guys! We also did a little experiment to see if fishes react to Jazz Music. Conclusion: Well Some do, Some Don’t!

After our input buffer almost empty, we though of eating ; Whats better than Vada Pav. We ordered Vada Pav at the local stall on the lake! It was pretty bad. Some famous person has said, ” Chilli is the mask of a bad cook” . The Vada Pav was filled with Chilli. This is a pretty old street food trick when they sell water/drinks by selling spicy food. Busted!

We then had some ice-cream from the “What-we-thought-local” shop called Havmor. But it was some real bang on buck. Totally awesome! There was no Kwality Walls, Cream Bell or Mother Dairy there but Havmor was infact a chain of Ice-Cream Parlors Spread across city.The Raja–Rani flavor ice cream is pretty good, just in case you have trouble choosing.

It was now time to leave this pleasant lake and move to some godly place. ISKCON Temple was the place. There is a bus stand outside Kankaria Lake and you can get direct bus to ISKCON Temple. We passed over the Sabarmati Lake front and captured this beautiful sunset.


It took us quite a while to reach there. People were happy to help us when we wanted. Good People always smiling! We reached ISKCON Temple near the time of arti and as always the ISKCON Temple Arti is pretty hair raising! We paid our tribute to Lord Krishna and stayed there for a while. Bliss!

Then after the ARTI was over, we had the prasad and went outside, collected our shoes and ate chinese samosas. This is a pretty standard ‘delicacy’ in any Indian Marriage. Its basically a Indianized Fried Wonton and is served with Momo Sauce. Still better than that Vada Pav!

The Question was now what? Go to the BaseCamp or Go somewhere else? Obviously Go somewhere else, But where? We were suggested by a person to do visit the “Drive-In Cinema” . Its probably there in two Indian cities Mumbai and Ahemdabad. So, why not! Bus Route is way out of question suggested Here Drive. We took the Auto to “Drive In Cinema”. It basically a place where you can Drive into a large ground with your car and watch the movie out of the car itself. The Screen was huuuuuggggeee ! Dhoom-3 was being played. We joined in. Its a great experience but even if you dont have a car, there is a small auditorium built near the projection room that can accommodate you!
Drive in Cinema


There were small poles with built in speaker and Amps too, because if they had a central amp, then those long wires load the central amp a lot.

We enjoyed the movie and had “Dabeli” during the interval. It was way better than that Vada Pao and Standard Pop Corn. Its a type of Vada Pao only but a bit different.I guess they dont use Besan in the tikki/vada they have inside it. Prefer a butter Dabeli if you have an option.Below is the picture captured when the butter was smoked.


It was a bit spicy, but the chutney neutralized some of it. But the time the movie was over. We were hungry! Damm Hungry. We took an auto to Nehru Circle. It was 10pm so night charges apply! We asked the auto person to drop us off the circle as well. We found another good shop!

It served the best Vada Pao and Khasta Samosa Ever!

The Best Vada Pao in Town

The shop owner was a pretty nice lad. He was from Rajasthan and was very much patriotic about Gujrat and kept on repeating “Aap humare Gujrat mein aaye ho“. When asked about NaMo his words were sweeter than the Jalebi we had in the morning.

We ate Vada Pao and Samosa! The Vada Pao ( i am a fan boy of ) was a bit different than the one i had in Dadar,Mumbai near Siddhivinyak which is rather advertorial to be the best in Mumbai. It was spicy but good but this one was the best! 10/10 . When asked about the secret, he said he has a special chutney which uses Khumani (I guess). If you love Vada Pao go here! Its near Nehru Circle and opens till late!
Vada Pao



The samosa was also good. But it was the chutney that had all the magic!

Next we moved to a Pizza Shop-Real Paparika. Unlike Dominoes or Pizza Hut in Delhi, Amdavad has a lot of there joints which are essentially home-grown Italian Food Chains. Since we were half full, so we ordered the 4 pizza Combo! Surprisingly they have an unlimited food combo for 129 INR.
Late Night Pizza

Well the pizza was good. But not surprising.It was comparable in quality to Dominoes and far well prepared but was pretty basic! Next we moved to the local soda parlor to have some late night soda! The soda shop had a chach flavored soda that was worth trying.



As we drank the soda , we could see city getting ready for Uttarayan. Kite thread ( Manja) was being glazed with glass and various different kites were being made.Too bad we wont be in the city on the day! But there is always a next time.

Sada Haq Aithe Rakh Patang


As we were walking towards our apartment, we thought about various things, the people’s love for the city, NaMo, Food and It was never a bad time for some late night ice cream. Ice Cream anyone?
Havmor Ice Cream



આવ્જો (āvjo)



Edit: There is a bit more to Ahemadabad – The Sabarmati Ashram, Vintage Car Museum, Science City and Delux Gujrati Thali ! Maybe next time ! 😀

CoffeeBreak Tutorial #2 : Adding USB charging to an old Android Tablet

I am a sad owner of a BSNL PentaTab. It is a horrible tablet with a very glitchy hardware/software. Although, enough of the rant..It just gets the job done. I recently had an issue when the tablet stopped charging from its DC jack a week after its official warranty ended ( This always happens 😐 ). The tablet does have a USB-OTG and a Mini-USB for data, but does’nt support any charging via the USB interface. I fail to understand this.

I took it to the local service person, So that it can be handled “professionally” . That guy took some money and got the job done. But it failed again after a few days.In India, they dont give you any guarantee till when the repair would last. So, there was no point taking it back to him.


So, I planned to open it myself. I was surprised to see the board inside. It was hardly populated. :O

WP_20140315_003There were so many reflow-able spots.Maybe they use the same board for all their products. The empty spots “might” just be for SIM Module,Bluetooth or GPS (# Hidden Gold)

I felt heart-broken when i saw the bad soldering on the board. It was probably done by some untrained professional. This makes the board susceptible to shorts. Bad Manufacturer.

Bad soldering by manufacturer inside the tablet

Another thing that surprised me was that the onboard storage of 8GB meant there is an 8GB SD card inside. I wished to see some flash chips like the one on beagleboard. huh!

8GB SD Card So, this is what the manufacturer meant by onboard storage.

The AIM was to make the USB mini-B charge the tablet, hence by-passing the DC-Jack.

This turned out to be very easy. The grounds of the DC jack and USB Connectors were shorted due to the presence of a ground plane of the PCB. Next i took a small single stranded wire and soldered it shorting the positives of the DC Jack and +VUSB.
Adding #USB #Charging #Capability to an #Android #Tablet #Hack

And Boo Yeah! It can now be charged by any USB charger >1A.
Yeah! It #Works . So now it gets charged via USB too. #Juggad

Update: (13th April ’14)

I did a complete resoldering of the bad joints i saw earlier. The speaker was making insane click and screen too. The wires had gone lose.

Here is the final picture. I desoldered all joints and reduced wire length. The GND pad was a bit hard for my soldering Iron as it needed a bit more power. Then i cleaned the joints and laid out wires a bit more systematically!

Cleaning up some joints inside the tablet.

Shazam of Materials- Building the DIY Spectroscopy Kit from PublicLab

I recently got a DIY Spectroscopy Kit from PublicLab . I thought it would be nice to share my Build Log and subsequent spectroscoping most of the accessible light sources.I really loved when we used to work with the “Pro” versions of these in Physics 101 Labs.. I really never thought i could get one at home unless i built this.. This spectroscope is amazingly accurate as one of the tubelights i “probed” had almost identical manufacturers spectrum.. Wow

The kit came in a nice cardboard box and had everything you need to make your own spectroscope. It has:

  1. HD Webcam
  2. Flexible Cable for USB
  3. 45 degree cut wooden piece for fixing the cam.
  4. Good Quality Foam Tape
  5. A Water proof aluminium Conduit box
  6. A stencil/plan for the dark box
  7. DVD as a diffraction grating
  8. A very nice instruction manual
  9. Lots of Fun

The mystery box

Kit contents

Kit contents

Cutting the plans 
Box plans

Cutting the plansAssembling the Box

Make sure the inked/printed part stays outside. We dont want any reflections inside our dark room. Add the Foam Tape to secure the joints and add a piece of foam tape on the spot where its written “Bottom” . We will peel off the other end when we assemble all the components in the conduit.

Foam tape on bootom boxSplit Open the DVD

A DVD is a combination of two parts(actually many but we are concerned about two) . A Diffraction Grating is the heart of this device. We use the one made by a commonly available DVD. The reason is : (Source:Wikipedia)

“Ordinary pressed CD and DVD media are every-day examples of diffraction gratings and can be used to demonstrate the effect by reflecting sunlight off them onto a white wall. This is a side effect of their manufacture, as one surface of a CD has many small pits in the plastic, arranged in a spiral; that surface has a thin layer of metal applied to make the pits more visible. The structure of a DVD is optically similar, although it may have more than one pitted surface, and all pitted surfaces are inside the disc.”

So, take a small blade (in case you dont have big sharp nails) and try to apply force on the disk from the circular edge i.e the thin part and you will soon be able to separate both ends. Discard the shiny part and “cautiously” handle the second part. (No fingerprints)

Split open DVD

You can see this (Warning:PDF) for more on the calculations and preparation of grating part!

Now cut a sector of this disk and inspect it for fingerprints. Out of curiosity i applied some alcohol on the part with the intention to clean it but rendered it useless. So DONT use alcohol.

DVD diffraction grating

Next , cut a small portion from the farther end of the disk as tracks are more linear there.

Camera Time

The camera is a very beautiful circuit. Be careful with the USB cable provided its not that flexible as it looks.
The camera

Next mount the grating with the circular portion facing the camera. You also need to focus the camera by moving/unscrewing the upper black portion to about 9inches.

I advise aligning it a bit angled and not straight as shown.
Grating on the camera

Prepare the Mount

Now grab the piece of wood and stick foam tape on it as shown. Also use some tape on the sides for securing the wire for the USB camera.
Preparing the stand for camera

Now stick the camera unit on it and carefully stick the wire to the foam tape on the side. Be careful with the wire.


Open the conduit box and stick the black box we made earlier by peeling off the tape..
Opening the Case

I suggest adding the extra foam tape to hold the box firmly in place.

Adding extra tape helps in securing the black box better

Now add the camera and slide the USB cable out. Carefully stick the wooden piece with the Foam Tape on its bottom to the conduit floor inside the region of the black flap.
Imaging slit
Now you need a Cable Tie to hold the wire in place and reduce the tension on the wire. A tape will do the job too, less aesthetically though.
Now screw the cover of the conduit back making sure you dont press on the webcam and start searching for a CFL (We have LEDs now 😛 )

Focus Shift

One thing that troubled me and i would suggest the designers of the kit is that the regulator on the camera heats up a lot and it worries me a lot.Also the USB cable is a bit small.I had to buy a extension cable to enhance the reach.


A CFL is needed to calibrate the build. Basically the wavelengths of certain peeks are known and using these we can calibrate the equipment ( Calibration to know standard- Instrumentation 101) .

So, go to spectralworkbench . Make an a/c so that you can save the data.Next go to begin capture and follow the instruction on screen. Point your scope to a CFL lamp and you will see a live feed on the webpage. Try rotating the scope till you get a bright sample and then move the yellow bar to the spot. Make sure you get green first and then red on your spectra when moving Left to right (ProTip) . If not you can click on flip button. When set click the “begin capturing” button.. and you can see all the stuff being done. When you are happy with a stable spectra click save and fill the form.

You will then be guided back to the site to calibrate. Once the spectra is saved you need to click the calibrate button and click as the dialog says (Be sure you are logged in or “Something went wrong” pops up).

After calibration you can see the wavelengths on the x-axis.

Here are some of my spectra:


A blue LED from a STRIP


100W Phillips bulb. Extremely high IR content beyond 700nm

Bulbs are considered enormously inefficient as they emit large amount of energy they consume as IR which is not visible to human eye. Only a part of it is actually useful light. But camera’s do see IR . Check by seeing your remote’s Led thru your phone camera?
I always needed a proof of it ever since they taught this to me in 8th grade!
Here it is.


No wonder it contains Blue and Green


The classic 6500k spectrum from my 40W OSRAM Tube Light




The pure RED Light from a LED

The spectrum peaks at 625nm. Using Plank’s equation, E=Hv
We have E=1.984V ! Wow.. The value of vf according to the datasheet is 2.1V Typical and 1.8V actual. That’s pretty close!



You can see how vividly its true! The tubelight has a more peaky spectrum but the peaks are more or less aligned to the peaks/flats of the sunlight spectrum.

You also notice that sunlight has IR and UV content as well but tubelight doesnt!
Thats why people use sunscreen to protect them from UV!

The best thing about this web based UI is that it is crowd sourced so, If you click on Find similar you might get the same bulb brand or maybe material that somebody had tested. like i found a person/sample with almost same spectrum as i had. If he had given a much descriptive account of his bulb it would have been a lot useful

compIf you want to play around with Spectroscope without attaching it to webcam and just observe it with your eyes there is one by IUCAA here .

Check out the instructable here!



CoffeeBreak Tutorial #1 : Setting up Ubuntu 12.04LTS 64bit to say hi to MSP430

I am starting this series to document all the hiccups/issues/problems, i face while doing stuff i like.This can be a log as well as a help to fellow makers.

I recently moved to Ubuntu on a new system as my Laptop had started to develop some hardware issues with the Graphics Card that require uncalled investment which i am not currently interested in! I am preparing for some exams and this post was a result of my small concentration session 🙂

PS: I am still a Linux Noob and follow the “google-when-stuck” strategy or ask for help from my friend RKS!

Now lets get started,

We need the following modules/packets to get running

  1. binutils-msp430- Binary Utilities for MSP430 -Linker,Assembler etc
  2. gcc-msp430- GCC compiler
  3. msp430-libc- C Libs
  4. mspdebug- the programmer

So, to get them all just type this in Terminal (Ctrl+Alt+T)

sudo apt-get install binutils-msp430 gcc-msp430 msp430-libc mspdebug

This will install all the required files.

To check that all went as you wanted you just type the following to get the corresponding outputs as shown:

on typing


in terminal you should get:

Screenshot from 2014-02-17 18:28:28on entering mspdebug rf2500 you should get:

Screenshot from 2014-02-17 18:29:18Now why “rf2500”? This is the device that the launchpad uses while programming the on-board MSP430 using spy-by-wire.

Now lets see how the device enumerates on the USB bus by doing



on terminal

The output before and after is shown:

Screenshot from 2014-02-17 18:06:25You can see the device 008 here is our Launchpad!

On connecting the Launchpad and running mspdebug as before we get:

Screenshot from 2014-02-17 18:30:55leaving us with mspdebug prompt to play with! For the time, lets just exit.

Now lets start with the blinky here. This was written for CCS but lets see if it works for gcc as well!

A few modifications with geany IDE and save it as main.c in home !

Screenshot from 2014-02-17 18:45:40The next task is to compile the c file into an .o file using the msp430-gcc and then linking it to get an .elf file which can be burned onto the chip. Seems a lot? It is fun though!

The commands are as follows:

msp430-gcc -Os -Wall -g -mmcu=msp430g2553 -c main.c

-Os -Optimization for low space

-Wall -Warnings all (show and not supress)

g – is used to embed debug info

-mmcu -which mcu?

-c to compile

Screenshot from 2014-02-17 18:52:14It throws up an ignorable warning!

Now lets link it ! You might have noticed a .o file created in home.

msp430-gcc  -g  -mmcu=msp430g2553 -o main.elf main.o

-o is to give out the output file. rf2500 accepts in .elf while BSL ones take .txt. We are concerned about .elf .

Screenshot from 2014-02-17 18:52:33Now you see a .elf file as well ! We have got our gold \m/ !

Now just burn/download it to launchpad using :

sudo mspdebug rf2500 'erase' 'load main.elf' 'exit'

erase- it will erase the mcu

load will (down)load/burn the file into the mcu flash.

exit-will exit.

Screenshot from 2014-02-17 18:52:57If everything went well, we will have a blinking red led on board. Phew!! Thats a lot !

You can play with the commands on mspdebug and try setting breakpoints and doing most of the things that can be done in CCS !

Update: RKS tipped me with an easier recipe for GUI friendly compiing! He sent this screenshot where he configures Geany to compile the code with 2 keyboard presses and 2 button clicks! Thats FAB!


He says,Go to Menu-> Set Build Commands. You can then add a label as Flash label will not be available over there by clicking on it. and fill the fields as he mentions:

Compile: msp430-gcc -Os -Wall -g -mmcu=msp430g2553 -c “%f”

Build: msp430-gcc -g -mmcu=msp430g2553 -o “%e.elf” “%e.o”

Flash: mspdebug rf2500 ‘erase’ ‘load %e.elf’ ‘exit’

and hit OK! You are done! Thats pretty nice and cool! Thanks Champ!! 😀

Update 2: It can get easier(lasier)! Just 3(4) Keystrokes..

Add what you did for Flash menu in the execute field as in the screenshot. So now its just F8–>F9–>F5–>Enter

Screenshot from 2014-02-17 22:52:38

Comparison to CCS:

Pros: Fast and less memory intensive as everything is on the command line. Setting up is fast and most code can be cross compiled,Free as in no code limit,Geeky,Split Second Compilation 😀

Cons: Less supported, boring without a GUI, Serial/UART is not supported out of the box,Smaller community!



Sometimes you may also need to add a udev rule so that the system can identify the msp430 launchpad.Follow this

BTW my Configuration: Ubuntu 12.04LTS 64bit , Launchpad v1.5

MakerFest 2014

I recently took part in the awesome event ‘MakerFest’ organised by MJFF at NID in the cool city of Ahemdabad,Gujrat. This post is an attempt to cover the event as pictorially as possible. We arrived a day before the event and made preparations for the workshops we had to conduct. That was pretty grueling i must say.. 40 hours of pure insomnia..At the end of the day i had a lot of stuff ready for the event next day! We soldered and programmed 8 Beating Hearts for the team to adorn.

All Hearts soldered just in time

8 Hearts 😀

We also made a test rig to test the inductors for boost converters in our projects.
Inductor Test Rig

We use the inductors in a modified ‘joule thief’ circuit that powers the setup.Above is a board for the illuminated eye loupe that helps you to look at smd components up and close. A magnified image for a 0603 resistor soldered on the hearts in shown below
LED thru the eye loupe

After the heart was up and running the view was infact pretty pleasing.
LED Heart

DAY 1:

Day 1 was pretty hectic.We reached NID on time. It was a beautiful campus, that certainly justifies the design part in their name.We figured out our stalls had not been assigned and went on to set it up ourselves and soon we were being barbecued in sun.Wrong spot we chose? Thankfully reinforcements arrived from the college and we were having people coming from all walks of life at out stall,Some engineers, scientists from ISRO centre,designers and what not!

Welcome to NID


Caught them early on! Before they were brutally removed by visitors 😛


As other were busy explaining and my curiosity thresholds were being compromised,I went on to have a look at what other were showing!

Here is a BATMOBILE made by LD College of Engineering,Ahemdabad


There was an interesting concept of plug and play boards to learn electronics.It basically has lot of different modules like amplifiers, adders, USB power,capacitive sensor etc. that can be plugged to make projects. I suggested him to add Arduino or any microcontroller too. He said it should be more of analog to learn better.
Electric Bits

I also saw the clock made by Anool from .I could not find him the first day.But managed to catch up with him at the lunch counter the second day! It was Nice meeting him!
Anool`s Project

There was also a representative from mLabs showing off their “Memristor” work!

Memristors at MakerFestA team from Autodesk was also demonstrating their Autocad123D and other softwares at the event.They even brought a MakerBot to show the prints. It was damn good.

Autodesk with MakerBot

Since now we have started talking about 3D printers, There were a lot of 3D printers being showcased at makerfest this time around. They were made for Makers and well as industrial purposes.Its glad to see the revolution picking up in India.

This is a 3D printer for commercial purposes by aHa Industries. They are based out of Rajasthan!

Aha 3D PrinterKaran from KCBots also demonstrated his 3D printer which can be had for about 40-45k ( $720 ). It supports PLA only as it doesnt have a heated bed.

KC Bots 3DPrinter

Students from Manipal, now a startup called Fractal Works, also showed their 3D printer.It supports ABS too.
3D PrinterThey printed a batman mask!

3D printed Batman

Then i moved on further to see the scooter from the movie 3 Idiots showcased by its creator.
3idiots ScooterIndian Craftsmen from an NGO were demonstrating their work.Its a pity how automation has hit their belly and NGOs are supporting them so that the art can be preserved.

Cutting brass boards

He made a nice butterfly by placing the pattern and cutting it, while i was standing and clicking pictures..
A butterfly of Brass

I could not see more on DAY 1 as I had workshop to take on “Illuminated eye Loupe”. Here are some pics from the workshop.
Teaching people to solder

A Mechanical Engg. Learns to solder

The First to Light 'em UP

Next we packed our stuff up and headed to the guest house to get ready for the next day! We had a lot of workshops the next day like the LedDoodler, Batteryless Remote, Batteryless Dice etc.

Day 2:

Since, we had a larger team now, so, we divided the manforce into halves such that one would manage the stall and another would do the workshops.I chose booth and frequented both spots so that everything goes on smoothly. In the time i saved from lunch, I visited the spots i missed earlier.

It was cool to catch Ankit Daftery from Arduino India showing some interesting stuff with Yun and Tim LED matrix from Wyolum.

Ankit from Arduino India setting up the stall

A Hyper realistic Wax Mannequin made by NID students.It baffled me for a while 😀

Hyper-Realistic Mannequins

There was also an extremely nice rangoli made near the entrance showing the MakerFest Logo !

I also saw the EpiLog Laser Cutter at FabLab Stall in the MakerFest itself. Its a great machine(tool),wish i had one :D. They also showcased the other fablab machines like Roland CamRunner Vinyl cutter, Weller soldering Stations etc.
Ooo. Epilog Laser Cutter

I was amazed to see mozilla foundation at the event demonstrating the phones running..firefoxOS. For the curious ones, Its a pretty cool OS, based on Android itself but runs a different event or application layer. It has better battery performance and it was pretty smooth!
FireFox OS UI

FireFox OS Phone

While i was running back to the boardrooms where workshops were being conducted, i managed to catch a glance of Sam Pitroda,Advisor to the PM and Head of NIC.

Sam Pitroda at the EventThere was a setup showing how Ceramic glazing is done and they had these nice cups that caught my shutter.


I also saw the plotter bot made by anool from Wyolum.It uses curtain fittings and water bottles as counter weight.Its really a nice idea that i will test shortly!

Anool`s Plotter Bot

There were other fellow student exhibits showing an Electrified Bicycle, a DIY Microscope, A Life Aid for Hearing Impaired and a puchka (aka Gol Gappa) maker.

Puchka Maker

The workshops were jam packed today. We saw people from all walks of life coming,seeing and making electronics.It was fun teaching and interacting with them.

Busy Busy Busy!

The day ended with a panel discussion on stage, where several issues related to maker movement were discussed. A point by someone that i remember was that The Father of the Nation, Mahatma Gandhi was a maker himself and the maker culture is inherent in India. What needs to be done is to bring out this maker from our hearts and minds out in open!
Panel Discussion

Soon, we were on our way back to the guest house where i open the Badger Anool gave me and felt delighted!
Thanks a lot for the Badge

A lots and lots of Thanks to the following:

  1. Dr.C.P. Ravikumar from Texas Instruments India for sponsoring our visit to Amdavad
  2. Prof.Dhananjay V.Gadre for mentoring,helping and guiding us all along.
  3. Vinod Sir for being with us always and managing the work and helping us by saying “Chinta Mat Karo, Sab Ho Jayega!”.
  4. Priyanshi for arranging accommodation and making us feel home.
  5. Nidhi,Saral,Netal,Ishan,Ritika,Priyanshi for being a great team to be with!

You can have a look at the Flickr Set here!

Other pics i pulled up from other peoples systems are here on skydrive(soon to be OneDrive)!



IndianTinker Goes to MakerFest-Ahemdabad

Happy New Year Readers.. Wishing you a great one ahead and hope you get to do what you love to do and excel in the same.
This new year, I am going to MakerFest 2014 organised by Motwani Jadeja Family Foundation (MJFF). This is probably the first of its kind event in India where several makers of India come up to a single platform to collaborate,teach,learn and evolve.

This edition is being organised at NID,Ahemdabad from 4-5th January and has a lot of awesome makers coming( I know some only sorry! ) including Anool Mahidharia, who was behind the OSHW Badge that had a pretty cool paper display and lot of cool other cool makers.

You can see other makers coming to the event here .

There will be lots of fun workshops taking place , and i am also taking one.. Its called Illuma Eye Loupe. What it involes is having a single battery driven LED illuminated eye loupe that helps in taking a closer peek at those SMD connections we make. Normal Eye Loupe makes it darker as we close up and not everyone enjoys the luxury of having a personal USB microscope/or even a normal one. So, we used to have this problem while working in the lab(TI-CEPD) and hence, the solution was found by making an illuminated one. There were several design iterations (4, I guess ) for the same. First we tried with a normal perfboard and used a 9V battery to do the job. But the battery was very clumsy to handle as one hand would always hold the battery.. Then we tried with other batteries but they wont last long. 2xAA would again make the form very big!!

Not done.. huh?

So we went for a Single integrated PCB that would have an inexpensive boost converter that would boost the 1.5V from 1xAAA battery into 3-3.7V for the white LEDs. Now, when using the thru hole LEDs the form got a bit thick and hence in the final version we went for the SMD LEDs.

I have a couple of images on flickr of the photographs you can click using a cell phone camera and this eye loupe(earlier version).



So, Once we were final with the design, We sent the designs to a local fab house to get the PCBs made. We got them just in time..Here is a pic of them..

Unfortunately, The Fab House didnt drill/mill the centre eye loupe hole. This is what i am doing now.. using an old-blunt-misaligned spade drill bit a file and a dremel.


Just managed to drill those holes. The steps were

  1. Go to market and search new spade bit.
  2. Step 1 , Didnt work.Hammer the bit to make it somewhat aligned after securing it in the vice.
  3. Step 2, didnt make things that good..
  4. Drilled in ascending order 2.8–>4–>4.5mm
  5. Then used the misaligned bit to drill it thru
  6.  Used a paper cutter to cut excess debris of the Glass epoxy mesh
  7. Use a dremel with a sanding bit and make them smooth to fit the loupe.

The result is as follows:

WP_20140102_002 WP_20140102_001

There are a couple of workshops folks at TI-CEPD are orgainising..
We have a RGB doodler by Nidhi ,A batteryless TV/DVD/STB Remote by Ishan and Netal , A Batteryless Dice by Ritika n Priyanshi and A very Easy to make homo-polar motor by Saral.

I would like to thank Texas Instruments India for funding our travel, Nidhi for setting everything up, Prof. Dhananjay V.Gadre for helping,guiding and motivating us at every moment and Priyanshi for arranging accommodation..

I will post (well almost live) images on instagram ,twitter and facebook. Be sure to follow…
Looking forward to it.

આવ્જો (āvjo)


Digging into an old Nokia 2100

Well, i have been opening up stuff ever since i was a child with a screwdriver, but now that i am studying engineering, It actually adds more fun to it. I had an old Nokia 2100 that i would take/sneak to school. Now its in a bad shape and the screen needs replacement. It had been lying on my desk for a few months until now i wanted to break it up and see how “Nokia” did it back then.

Thanks to  nokia`s longevity, it seems that the phones are still somehow alive , thanks to which the repair supplies market is not dead and turns out to be a helpful resource to what the black chips on the board do.

The beautiful board inside the phone


The MAD2WDIC V16 baseband gsm processor from TI


The COBBA(Audio I.C. 4370793) It seems to be handling all the audio processing on the device. on the side is the Charging Control I.C. 4370621 with a big SMD 0.22 resistor for current sensing


The complete PCB. It also has a Signaling processor 4370781 HAGAR, a Chip Flash LRSI3AI and a NMP707 series Chip Power Supply IC-NMP70719


The design is such that everything connects to the main pcb using copper strip contacts making is highly modular,repairable and shock absorbent as we know nokia phones used to be.


4370433 IC i could not find anything about


The Buzzer..


The contacts galore


The display and Keypad.

To view the complete album go to my flickr page here!

Hoping to see some comments! 😀


EventReport: Renesas GR Sakura Competition India

Today, I got a chance to present my project at the finals of the GR-Sakura Design Challenge in New Delhi at Radisson Blu-Dwarka. Although i did`nt win ( 😦 ) But, It was a great experience to be there and meet new fellows. I clicked some pictures of interesting projects and prototyping ways. It was great to see people use 3D printed motor mounts and extensive use of android phones in projects. One out almost every 5 projects had an android assisted interface.

The Radisson Blu Hotel, Dwarka

My Project

My Setup 😀

First one to reach!

The Stage!

Yet to start!

The Registration Desk

Exclusive Preview to Kurumi Board

Preview To Kurumi Board

Automatic Diesel Generator Control

Automatic Diesel Generator Control by Power Grid

Train collision avoidance system

A Train accident prevention system with sub-metre accuracy using GSM-GPS-GLONASS-WAD made by very senior person with about two decades of experience in designing safety systems. He also won a prize !

Farm Automation based huge project

A huge farm automation project with almost everything LabView+Android+Sakura+Servo+Panel Tracking.. and the list goes on!

IIT Bhubaneshwar used 3D printed mounts

Another Great project from IIT,Bhubaneshwar.It studies the control requirements for designing a Uni-cycle.These guys have a huge stratasys 3D printer at their college which they call RPM-Rapid Prototyping Machine. They built the mounts for the motor and pulleys using solid works and later printed them.

PLC based on Sakura

A PLC based on Sakura Board

Vibration Analysis

Another interesting project which uses accelerometer and Temperature sensors to determine whether a rotary machine follows the ISO standards!

Project Idea

I met a really interesting person at the event. Butani Sir is from Rajkot and has a very good knowledge of topics ranging from Microcontrollers ( you name any! ),Dev Boards, Aero-modelling,Graphics and Hands-On in general. He is a professor at a college in Rajkot and has a Btech,Mtech in ECE.This is his idea of a final project would look like! Cool Sketching 😀

Butani Sir and his project

Butani Sir while packing up (He too has a Chronos)!

Nice Way of Prototyping

How he did the board was real cool. Using his exp. from aero-modelling he made it almost like a shield and glued dangling components. Tip for ppl who prefer the perfboard

Intense Moments


Judging in Process

The Entire Setup for demonstration

Prize Distribution

The prize distribution

To view the entire set go here.

It was a great event.This was their first edition. If they ever plan to scale it up, they can see how TI does it in India.

Looking forward to hearing from you all!