1. Improving SBHS Remote-Triggered Virtual Lab Server and Website
Under the guidance of
Prof. D. B. Phatak
&
Prof. Kannan M. Moudgalya
Mentors: Rupak Rokade and
Inderpreet Arora

2. Team members Software Interns Hardware Interns
Debakanta Kar, NIT Rourkela
Deep Bhattacharyya, NIT Trichy
Sriya Sainath, NIT Rourkela
Hardware Interns
Ram Srivathsa, NIT Trichy
Rupesh Gupta, NIT Trichy

3. contents Why SBHS Virtual Lab? Objectives SBHS Virtual Lab Walkthrough
Bugs Fixed
Features Added
Admin Features
Health Monitoring
Maintenance Scripts
Proposed Architecture
Hardware
Testing
Challenges Faced
Learning
Future Scope
Links

4. objectives Admin features Health Monitoring Bug fixing
Proposing another architecture with load- sharing and scalability
Testing both architectures
Other miscellaneous features

5. why sbhs virtual lab? Small and Portable Remote-triggered Open-sourced
The objective of this lab is to help perform experiments in the Instrumentation and Control System labs virtually, and yet have close to real life experience.
Features :
Small and Portable
Remote-triggered
Open-sourced

6. A brief walkthrough for sbhs virtual lab
A Single Board Heater System

7. BUG FIXES The Problem of Zero Temperature :
Cause : Loss of connection to SBHS
Opening a new Serial Port in between the experiment.
Cannot Connect to Server Message in Client App :
Cause : Unhandled Exceptions in Server Code.

8. BUG FIXES In initial slot allocation Improper Board Allocation :
Cause : Foreign key mismatch of accounts and boards tables.
IndexOutOfRange Exception :
Raised while allocating a board to the first user
Occurs when trying to allocate boards when none of them are online
Cause : Trying access an element from list of Probable boards which is empty.

9. BUG FIXES Incorrectly sorted Bookings :
Cause : Didn’t take slot orders into account.
Deleted slots displayed users :
Cause : Undelete App causes delete command to act as soft-delete.
Empty Experiment Log Download :
Cause : Discrepancy in file created and downloaded.
Invalid MIDs Displayed :
Cause : False Positives resulted while scanning for SBHS in USB ports due to Arduinos connected.

10. Features added ADMIN FEATURES Temporarily disable boards for users
Unless board is already under use
Admin can still access the board.
Test any online, unused board
Monitor logs of on-going experiments

11. Features added ADMIN FEATURES Update MID allotted to user
MIDs in sorted order
Auto-complete usernames
Auto-refresh board images every 25 seconds
Interface to download users data files based on slot date-time

12. Features added HEALTH MONITORING
An hourly testing to check board connectivity and working condition, and mail the admin if any abnormalities are detected, along with possible causes.
Scans all connected USB ports for SBHS
Test all detected boards with fixed sequence of system inputs and analyse their responses.
Mails the admin a list of defective or detached boards
Temporarily disables the defective boards
Updates the database accordingly
In the load-shared architecture, also aggregates data from slave servers

13. Features added SCRIPTS TO AUTOMATE SERVER MAINTENANCE
Semi-automated script to generate rules for webcam connection
Extracts information about the camera and links it to a board-ID
Allows existing rules to be modified
Automatic script on server start-up to initialize all boards and provide necessary permissions to Apache
In load-shared architecture, scripts to synchronize the clocks of master and slave systems, and accumulate data from the latter.

14. Features added OTHER FEATURES
Automated Script to set-up server on a new RPi and make it ready to be added as slave system.
Separate local file to store system-specific credentials for security purposes.
Update Apache configurations to support Apache 2.4(Latest)
Unified client code for both implemented architectures

15. Proposed architecture
Requirements :
Load Sharing
Reliable
Scalable
Solution Proposed :
Master-slave architecture
Inherently, Load shared and scalable
Use of Raspberry Pis as slave system increases reliability in comparison to USB hubs .

16. Proposed architecture

17. Proposed architecture
WORKING:
The master keeps a mapping of slaves and its corresponding board.
The boards are connected directly to the slaves and hence, all their requests are bypassed to the slaves without the master server’s intervention.
At the end of each slot, the health monitoring script is run on the slaves, and the master aggregates the data from them as it finishes executing.

18. SBHS Grounding Problem
Shorted the shield pin of USB with ground pin.
Failure to do so would mean noise gets impressed upon data signals, causing communication failure and dropping packets.
Arduino based
Switching Control
Developed code for arduino nano which would turn on/off the SBHS devices connected through relay boards.
This was successfully tested by sending commands through remote user using python script.
Building further on this, logic could be developed to turn off SBHS devices when not in use.

19. DESIGN LAYOUT OF ATMEGA16 MICROCONTROLLER

20. Testing
Both the architectures were tested for hours with multiple clients running simultaneously.
Every new feature added was tested individually during the experiments.
The load-sharing architecture turned out to be more reliable than the former one.

21. Challenges Faced Version compatibility issues:
Upgraded project structure from Django 1.6 to Django 1.11(Latest)
Removed old dependencies
No proper documentation:
For Classes and Methods.
To setup the existing server from scratch.
To recreate bugs.

22. LEARNING Web Development in MVC based Frameworks(Ex. – Django)
Configuring Apache
Bash Scripting especially event-triggered scripts.
Team Collaboration through git
Testing Server in Production mode.

23. FUTURE SCOPE
Labs with micro-controller based device can be converted to similar virtual labs.
The basic framework explained earlier can support it with device specific modifications.

24. LINKS The project’s codes and ReadMe can be viewed in the links below:
Former Architecture
Load-Shared Architecture (Master)
Load-Shared Architecture (Slave)
Project Documentation For Developers

25. THANK YOU