Saturday, 9th August 2014

Let’s generate some signals!

Here is our tiny sine wave generator for sound and waves experiments.

attiny1

The ATTINY85 based board which can take square wave as input and generates sine wave. In the picture- board and the completed module.

ATTINY 85 is the high-performance, low-power Atmel 8-bit AVR RISC-based microcontroller combines 8KB ISP flash memory, 512B EEPROM, 512-Byte SRAM, 6 general purpose I/O lines, 32 general purpose working registers, one 8-bit timer/counter with compare modes, one 8-bit high speed timer/counter, USI, internal and external Interrupts, 4-channel 10-bit A/D converter, programmable watchdog timer with internal oscillator, three software selectable power saving modes, and debugWIRE for on-chip debugging. The device achieves a throughput of 20 MIPS at 20 MHz and operates between 2.7-5.5 volts.

The ATTiny85! In the DIP configuration,  is about 9mm x 9mm, can be programmed using the Arduino IDE, runs on as low as 3.3V at pretty tiny amperages. Here is the pin configuration…

We programed it using USBASP programmer from our microhope project.

mh-usbasp

After programing the chip, now we can use it with ExpEYES as a sine wave generator. The connections are made like this….

attiny-connections

pin1 is RESET pin2 is input where SQR can be connected and pin 3 is the output. The module can be powered usent external USB or with OD1 as shown in the pic.

To reset pin 1 (marked as P1) should be connected to GND for a fraction of second. This is useful to obtain lissajous figures for which two modules can be used. Both the modules can be powered with single USB.

attinylissa

We also wrote a program in python for lissajous figures.

Here is the amazing result…..

lis2 lis1lis3

I also worked on few python programs to finalize them. Now almost all the programs are ready.

Here is my today’s activity on Github

Friday, 8th August 2014

Joy of doing….experimenting n exploring……

It’s awesome to work here at IUAC ( Inter University Accelerator Centre) New Delhi.

Labs are open 27X7…. all the facilities are accessible….. Have a new idea? ….work on it ….. develope ….design… get it fabricated in the workshop….test it in the laboraty….. modify…redesign….assemble …and you are done!!! Its awesome to see something virtual from your thoughts ….to a real thing on your table….

Developing new low cost science experiments……… to put it in simple words…bringing the cost of quality lab apparatus from few Laks to few hundreds………

But that’s not the only thing……It all open source……FOSS is the best thing that has happened in couple of centuries…..
#ExpEYES #FOSSASIA   #GSoC

Today we did a lot of coding work. I had already written python program to plot fetch data using sensors through ExpEYES and then plot the graphs. We re-wrote some of these programs to obtain graphs in real time. And the results are amazing.

Modified and finalized the following python programs…

  • pendulum-echo.py : Program to study oscillations of a pendulum using ultrasonic sensor sfr05 (position detector) by plotting real-time graph
  • coupled-pend-real-time.py : Program to plot oscillations of TWO coupled pendulums in real-time
  • motion-airtrack-echo.py : Programe to plot position time graph for vehicles moving on linear air-track
  • motion-compare-airtrack-echo.py : This program allows to plot position-time graph af motion of a vehicle on an air track.
    One can take multiple trials and view all the plots. this can be used to compare different aspects of motion
    like velocity, acceleration etc…
  • motion-two-srfecho.py : This program allows user to use TWO motion sensors (srf-05 modules) and plot both the graphs
    in real-time. This can be used for studying collisions, conservation of momentum etc…on air track or also frictionless track.

Sill working on programs for sound experiments….. Hopefully tomorrow, it will be done…

Here is a link to my Github repo..today’s work

Thursday, 7th August 2014

Today in the morning, I reached IUAC (Inter University Accelerator Cenre ) New Delhi. Started working on the experiment program codes with Ajith sir. We got the air-track set-up for doing the mechanics experiments. Repeated some of the motion related  experiments to study the changes required.

We modified the program for using srf module to plot position time graph. Now we can fetch the position-time data and store it in a file and then plot the p-t, v-t and a-t graphs.

We wrote another program to plot this graph in real -time. This program enables students to see the graph in real time as the glider moves on the air track. Here is the experimenta set up…

airtrack

 

We also set-up a pendulum experiment using a thick metal block and suspended it using  long strings to have a pendulum of large time period.

The program is written to plot the position of pendulum using motion sensor. Committed the same to Git repository. The plot shows the smooth sine curve of oscillations.

IMG_20140807_173110

Tried the experiment with motion sensor using toy cars. this can be an amazing demonstration experiment for highschool students.

toy car

Tomorrow we will work on sound experiments and finish the required programs.

 

 

 

Wednesday, 6th August 2014

Not much work today. Tonight I will be travelling to delhi and will be staying for four days, working on my project in Ajith sir’s teaching lab at IUAC.

Since a lot of work to be done in giving  finishing touch to all the experiments and the code, I have taken leave from college. It will be a good idea to sit at one place where all the facilities are available and work on the project.

I have taken all the required tools, sensors and ExpEYES kits.  We will be working on the programs that I have developed so far and do the necessary modifications.

 

Tuesday, 5th August 2014

Experiment to obtain Chladni figures is complete with the experimental set up and also the python code access the experiment.

This is the set up we designed and used ……

 

But It needs to be modified using a loud speaker as vibrations with the inductance coil are not large enough.

Also worked on giving finishing touch to python code of few experiments.

 

Monday, 4th August 2014

Since yesterday, I am working on giving finishing touch to the programs written so far. To meet all the goals of our project I must complete the Sound experiments part.

Ajith sir has designed a stand-alone variable frequency sine wave generator for my experiments and this will help me to complete almost all the experiments which we have mentioned in the proposal. We have also developed the experiments which are not mentioned in the proposal.

Today I have created a separate pages for few experiments. The page for coupled pendulums experiment is complete with the required information (Its Here).

GSoC Weekly Report 11

( From Monday 28th July 2014 to Sunday, 3rd August 2014)

This week I could develop two new experiments and worked on python code of the experiments developed so far.

Things we did this week….

  • Completed the set-up of sound resonance experiment.
  • Set-up experiment for studying Oscillations of Coupled pendulum. Performed the experiment in three different ways …
    • Both oscillating in phase
    • Both oscillating out of phase
    • One at rest and other oscillating

    Here is the experimental set-up….

    cp1

    The waveforms generated using DC motors after amplification…

    coupled pendula1 coupled pendula2 coupled pendula3

    The waveforms show beats as theoretically expected….

    The complete code is here…

  • Worked on another experiment for producing Chladni patterns using ExpEYES. For the experimental Set-up I used a CD as Chladni plate. SQR1 is connected to  a small inductor (a coil of wire with no magnetic core) and produces a sinusoidal magnetic field. This is then placed close to a small magnet attached to the plate, and so produces a sinusoidal force on the magnet. Two small magnets are placed on the edge of the plate. The inductor is placed so its centre is directly beneath the magnets and as close as possible to the plate without touching it.
  • on Saturday we could complete the set-up for resonance of cantilever beam  experiment. We used a plastic stick and bicycle wheel spoke as a cantilever beam. A plastic disposable cup is attached at the center of a loudspeaker using  adhesive ( which can be removed easily). Then the cantilever beams are fixed on the top of  the cup using cello tape. The speaker is connected to SQR1 and the frequency is gradually changed. when the frequency matches with the natural frequency of the beam it starts vibrating with large amplitude.

    The variation of resonance frequency with length can be investigated by cutting sections off the end of the plastic stick.

    This is the setup we used….

    resonancecant

    TO DO next week….

  • Work on common GUI for accessing all the experiments.
  • Continue working on documentation and code for all the experiments.

Saturday, 2nd August 2014

Resonance of a cantilever

Today we could complete the set-up for this experiment. We used a plastic stick and bicycle wheel spoke as a cantilever beam.
A plastic disposable cup is attached at the center of a loudspeaker using  adhesive ( which can be removed easily). Then the cantilever beams are fixed on the top of  the cup using cello tape.

The speaker is connected to SQR1 and the frequency is gradually changed. when the frequency matches with the natural frequency of the beam it starts vibrating with large amplitude.

The variation of resonance frequency with length can be investigated by cutting sections off the end of the plastic stick.

This is the setup we used….

resonancecant

Thursday, 31st July 2014

Chladni pattern is a n interesting example of Simple harmonic Motion. Today I devised a setup to produce these patterns using ExpEYES.

In Chladni patterns, points in an object undergo SHM with varying amplitudes. There will be some points where amplitude of SHM is zero, called nodes. If Small particles (sand / rangoli powder) are spread on the plate, they  collect at the nodes, ie along lines where the amplitude of SHM is small.

For the experimental Set-up I used a CD as Chladni plate. SQR1 is connected to  a small inductor (a coil of wire with no magnetic core) and produces a sinusoidal magnetic field. This is then placed close to a small magnet attached to the plate, and so produces a sinusoidal force on the magnet.

Two small magnets are placed on the edge of the plate. The inductor is placed so its centre is directly beneath the magnets and as close as possible to the plate without touching it.

 

Used python program to change frequency of SQR1.