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Fun times with DVG!

Here's a list of projects I have collaborated on with Prof. Dhananjay V. Gadre (In chronological order):

  1. AVR Workshop at VESIT
    (1 to 5 September 2005, VESIT, Mumbai)
    Helped organize/manage. Report and photos here.

  2. Multi Utility Sensor Network
    (December 2005 to March 2006, VESIT, Mumbai)
    During the AVR workshop DVG suggested us to clone the audience poll voting pad from the "Who wants to be a millionaire?" TV game show using a wired multi-drop network. It was also our final project at VESIT. Project synopsis:
    Designed and successfully implemented a wired sensor network capable of sensing and controlling physical parameters involved in any kind of process control. The project involved connecting Atmel’s AVR Microcontrollers over the RS485 bus in a multi-drop configuration. The microcontrollers were programmed in embedded C and the front-end was created using Java. The project was selected to be displayed in the Student’s Pavilion at Elecrama 2006 held in Mumbai by IEEMA. Elecrama is one of the largest biennial exhibitions of Electrical and Electronics products in the world. The project was awarded Distinctive Excellence at the Atmel AVR 06 Design Contest organized by Circuit Cellar (Entry/Abstract Link). An article decribing the project was published in Circuit Cellar 203 titled "Network of Keypads".

    DVG wasn't present physically, but he guided us over internet/phone. Our project guide was Prof. Abhay Khirsagar and we had three teams working on the project:
    • Embedded Hardware (from Electronics Engineering):
      Anurag Chugh (Me), Shweta Saraf, Richa Tewari, Rohan Raghunath begin_of_the_skype_highlighting     end_of_the_skype_highlighting, Charuta Ambardekar
    • Embedded Software (from Electronics Engineering):
      Sneha Lele, Kirti Ramnath, Varsha Mishra, Smita Kumar
    • Host (PC Side) Software (from Computer Engineering):
      Sanket Hase, Parag Shah, Shauvik Roy Choudhary

    Reports: Hardware Design | Embedded Software Design | Host Software Design

    We dedicate this project to Deep S. Bhattacharjee who left left us in a tragic accident during the floods of 26th July 2005. He was part of our Host Software Team.

  3. A Project for Delhi Metro Rail Corporation
    (June - July 2006, NSIT/DMRC Najafgarh depot Delhi)
    This involved retro-fitting Train Integrated Management System with Serial Device Servers . Every night DMRC maintenance staff used to access all of the 70 odd trains one by one in each of the three depots around Delhi and download data from TIMS on to their laptops to diagnose failures before they occur (preventive maintenance). The laptop connects to the TIMS computer via RS232 DE-9 Cable (straight cable - 3 wires only TxD, RxD, GND, 115200 bps 8-E-1, no flow control, approx 9000 characters per second). To make the whole process easier and decrease wear and tear on connectors and laptop and conserve man power, DMRC wanted us to make the system go wireless. We tried to replace the wired serial link with XBee modules and Atmega128s, but that obviously didnt work due to the high character rate. Bluetooth was out of question (Bluetooth data rate and range is as bad as ZigBees and as far as we knew, a bluetooth piconet can only have 7 nodes) Then we tried replacing the serial link with an ethernet device server. They had just been introduced in Indian market and we had a real adventure getting our hands on one of them. We combined that Ethernet Device Server with a WiFi Router and it worked successfully. We left the project at that and never heard from DMRC whether they implemented the system or not.
    A small Visual Basic software on the Client PC side could have been written to ping IP addresses of each of the 70 serial device servers (or WiFi Routers) on each of the 70 trains in the depot. This software would maintain an upto date list of all train parked in the depot at any given time and the user sitting at the PC could click on any train on the list to create a virtual serial port connection over WiFi/Ethernet to that train's TIMS and fire-up Mitsubishi's TIMS front-end PC application to download the data from the particular train. Of course we never got around to create this software either.
    The project was done at Najafgarh Depot in Delhi. The team comof three persons: Me and my friends Sneha Lele and Ranjit Puri. From DMRC's side, Mr. Jitendra Malik guided us. He was the Senior Section Engineer at Najafgarh Depot then.

  4. Various Development Boards for use during Embedded Workshops for Engineering Undergrad
    • ATmega8
      USB Powered, MAX232, 4 switches, 4 LEDs, 16x2 LCD, Thermistor, LDR etc.
    • AVR Butterfly Carrier
      USB Powered , 3.6V NiCd Battery, LEDs and Switches, general purpose area etc. The library I made for Butterfly has become quite popular!
    • Xilinx XC9572
      CPLD, Parallel Port programmable, DC powered, 7 segment LEDs, switches
      ... and many other boards too.

  5. Various fun project built around the AVR Microcontrollers
    • Blinking an LED on AVR using Lemon Power
      Four lemon batteries (pieces of lemon with zinc and copper electrodes) connected in series are enough to power a ATTiny13V microcontroller.Video here.
    • 3 Dimensional LED Hourglass based around Atmega32
      This would have been a super cool project, but we never got around to finish it off. I guess we need LEDs which would disperse light sideways. Video here.
    • A few projects based around charlieplexed displays
      There was a passing time when we became fans of the charlieplexing technique. This resulted in quite a few projects, some of which made it as articles in electronics magazines: EDN (Two digit Display) and Electronic Design (LED Bar graph). The one in Electronic Design became the Idea for Design of the year 2007.

  6. Fablab
    DVG has been associated with the Fablab program for quite sometime now and due to my proximity to him, I have had a minor bit of involvement with Fablab too. After the FAB5 conference (photos by Frosti GĂ­slason) I setup this site - which is an index to various Fablab websites around the world – to enable the community members keep in better touch with each other. Also I was forced to appear (with a dumb hat on! :) ) in this video of Electronic Birthday Candles which was prototyped on Roland MDX-20 Modela (standard Fablab issue).

  7. Textbook on the 8051 microcontroller
    (Jan 2008-May 2009)
    Cengage Learning approached us to come up with a new and revised version of Kenneth Ayala's classic textbook: The 8051 Microcontroller. 1.5 years and a zillion hurdles later, we finally finished updating the existing book and the updated version was published. The most significant additions include:
    • A few chapters on how to program 8051s using the C language.
    • A chapter describing newer variants of 8051 available in the market.
    • Appendices describe the installation and use of freeware open source development tools for 8051 and a low cost development system.
    • All diagrams have been redrawn and the coloured versions of those are included on the accompanying CD.
    We have made a companion site for the book here.

Prof. Dhananjay Gadre and I have been in touch ever since I emailed him after reading this article which appeared in May 2005 issue of EFY: