Development History of ExpEYES-17 / SEELab-3

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Development History of ExpEYES-17 / SEELab-3

describes the development of ExpEYES-17, vLabtool, PSLab, Python Powered Scientific instrumentation tool, and SEELab-3. From 2014 onwards. Documented in detail on Hackaday.

The circuits layouts were prepared by my father Dr Ajith Kumar, and I worked on the remaining bits which include soldering boards, firmware development, software work such as python libraries, graphical interfaces etc. For enclosure designs, I frequented various shops in Paharganj, New Delhi which dealt in laser cut signboards, and had nice tools.

Designed all graphics with Inkscape, and M.K. Packaging Ltd printed the cardboard packaging for ExpEYES-17. The devices were either screen printed, or UV flatbed printed

For Pick and Place Assembly , Beam Infotech’s facility was rented. Injection Moulding was handled by Tushar Sood’s Paragon Products Ltd at Okhla, New Delhi which deals in Geysers, and has a range of high end moulding machines.

July-2014

July-2014

Sent the first design for fabrication. Used a PIC24EP64GP204 micro-controller. Initial goal was to implement a 4-channel scope with at least 1 msps per channel, inputs with programmable voltage range etc. For waveform generation, added an ATTiny processor from Atmel. A 2 channel SPI DAC was used.
September-2014

September-2014

Corrected many errors of the first prototype. Added two arbitrary waveform generators, using 2x PIC1572 processors. Communication to these was established via 9-bit UART Cross talk between channels indicated the need for better ground plane design​.
October-2014

October-2014

Replaced quad op-amps with dual, separate op-amps for each channel. Minor bug fixes. PGA reference needs a low output impedance drive.
April 2015

April 2015

Hardware and software working as expected but packaging issues remained. Decided to go for 2mm round sockets and Berg strips for Input/Output connectors. Added an inductance meter also. Prototype made with acrylic cabinet. Added Ad9833 waveform generators.
April 2015

April 2015

One more round of prototyping to correct some errors.
May 2015

May 2015

Added ESP8266, for WIFI support, made some changes to I/O connector locations. tested with transparent UART firmware as well as eshttpd web server
May 2015 - 2

May 2015 - 2

Made a compact version with two bipolar channels and remaining unipolar channels. Called it Vlabtool.
6-June 2015

6-June 2015

Vlabtool went through many changes, PCB was revised 3 times before the final unit was made. It worked fine and had a local LCD display. Key Features- 12-bit offset control along with up to 32x gain control gave very fine oscilloscope resolution along the full voltage range 2.5ppm digital reference, 5ppm Analog reference 128*64 pixel OLED display that shows readings until a USB connection is detected
21-June 2015

21-June 2015

Decided to make a very low cost version [no high precision references, PGA etc], attempted gain control using op-amps and uC pins. , but it failed because of reverse voltage protection on uC pins via internal schottky diodes. 28-bit DDS sine wave generator with 0.004Hz resolution up to 2MHz was included. External amplitude control .
September 2015

September 2015

Added PGA back, for gain control. WS2812B RGB LED for status display The need was felt for more suitable I/O connectors than the existing banana sockets which require special connecting cables, and are largely cumbersome for quick prototyping in labs. Found some spring loaded speaker terminal connectors, that looked like a good option since any sort of wire could be plugged in
November 2015

November 2015

Made an adapter board to fix the speaker terminal to the main board so that the heights of the Berg strips align with them on the same plane.
November 2015

November 2015

Decided to make one batch of boards, and integrate with Orange Pi / Raspberry Pi. A prototype box was made with laser cut acrylic and vinyl stickers.
December 2015

December 2015

An injection mould was made to was made to fit an OPi/RPi along with the acquisition board
January 2016

January 2016

Made a laser cut enclosure for the vLabtool and got it screen printed. Four of these were distributed to developers of PSLab Akarshan, Praveen, Padmal and called Version 1. Featured on Hackaday
March 2016

March 2016

Several issues with making the ABS plastic cabinet were sorted out, and final assembly process was streamlined. four desktop versions were bought by Farook College, Calicut, followed by several other institutions.
July 2016

July 2016

Demonstrated at Startup Mission, Kerala.
July 2016

July 2016

Training Workshop on SEELablet for College Teachers organised by ICFOSS, Kerala.
August 2016

August 2016

Redesigned the unit with a different form factor, with 2 connector blocks. Added a 5ppm/C clock generator and 50ppm/C analog reference (5ppm optional) for better accuracy. After a couple of rounds of prototyping , one batch was produced, with a new plastic mould. This will be termed SEELablet-V2. Calibration is carried out against a 24-bit ADC, which at this point seems like overkill, so a step down to a 16-bit ADC is expected in the near future.
July 2017

July 2017

Upon request, technology developed for SEELablet, including schematics, firmware, layout, and software was transferred under open source terms to IUAC under the label of ExpEYES-17 in order to upgrade the ExpEYES project . A Special batch was made for ICFOSS which organised training workshops for schools.
Details are at expeyes.in
May 2019

May 2019

Training workshops for teachers organised by University of Calicut, under a DST funded project.
News articles can be viewed here
Feb 2020

Feb 2020

Exhibited at the India Science Fest, IISER Pune. Workshops organised for high school students
Feb 2020

Feb 2020

Malayalam Translations contributed by Amal M for the user interface. This adds to the existing french translations by Georges Khaznadar.