ExpEYES Development

Various prototypes that finally resulted in ExpEYES 17

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.
November-2014
November-2014
Lot of corrections and improvements. Everything seems to be working, demonstrated during Scipy.in 2014 conference at IIT Bombay.
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 .
25 July 2015
25 July 2015
31 July 2015
31 July 2015
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
February 2016
February 2016
Over 50 Experiments were developed with SEELablet and documented on hackaday.io.
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.
April 2016
April 2016
SEELablet Package included in Debian thanks to Georges Khaznadar. Home page for SEELablet
July 2016
July 2016
Demonstrated at Startup Mission, Kerala.
July 2016
July 2016
Training Workshop on SEELablet for College Teachers organised by ICFOSS, Kerala.
July 2016
July 2016
Range of Experiments possible with SEELablet. Featured on blogs
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.

SEELablet V2

SEELablet Version 2 . USB Mini Connector for interfacing with an Orange Pi.