Project

# Title Team Members TA Documents Sponsor
3 Smart Interface for ECEB Research Solar Panels
Texas Instruments Best Project Award
 Dillon Vadgama
Douglas Lee
Sachin Reddy
 Shaoyu Meng design_document3.pdf
final_paper1.pdf
presentation1.pdf
proposal1.pdf
video
# Problem

In 2018, a fire broke out on the roof of a Walmart in Beavercreek, Ohio due to Tesla’s unmaintained solar panels suffering from hotspots. These hotspots resulted in the cracking of the back sheets of the solar modules and compromising their electrical insulation. There was no protection system to detect this type of unwanted behavior and shut down the system before a fire broke out. As a result, Walmart sued Tesla over the flaws present in their solar panels.

Our very own ECE Building has a roof of 60 solar panels used for research; however, there are no protection interfaces between the solar panels and their connections to the power inverter. A smart interface box attached to each solar panel that monitors system behavior and has the ability to shut off the entire operation could help prevent a disaster like Walmart’s.

This project was initially pitched by Professor Arijit Banerjee and generated interest from several students. After a meeting with Professor Banerjee and David Null, two teams working on two separate projects related to the ECEB solar panels were created. It was decided that our group (Dillon Vadgama, Doug Lee, and Sachin Reddy) will be working on the Smart Interface Box for the ECEB research panels. The other students will be working on another project relating to the set of solar panels providing the building with power.


# Solution Overview

Our solution for monitoring and controlling our solar panels will be a smart interface box mounted directly to the solar panel. Electrically, the interface box will be connected directly to the output of the solar panel and will have the ability to configure how many cells will be connected to the power inverter (32 cells, 64 cells, or 128 cells). The system will be powered from an isolated 12V supply and an Ethernet interface will allow users to configure and monitor the solar panel through a server/PC. Because the power generated by the solar panel will be running through the smart interface box, we will have the ability to detect overcurrent/overvoltage conditions and disconnect the solar panel if necessary. Lastly, connections on the interface box will be available to attach thermocouples. Doing so will allow us to measure temperatures on different parts of the solar panel and disconnect the solar panel to prevent a hotspot disaster.

The interface box will have the following key features:
- The output of the interface will be configurable to be connected to either 32 cells, 64 cells, or 128 cells.
- The output of the interface box will be protected from overvoltage and overcurrent.
- An onboard microprocessor will allow for communication and measurement of system parameters over an ethernet connection.
- The box will be powered from an isolated 12V PSU.
- Should the 12V power supply fail, the output of the interface will be disconnected from the solar panel.
- Onboard LEDs will indicate the operational status of the panel and interface.
- When the system is not communicating via Ethernet, the configuration of the interface can be controlled manually via onboard - switches.
- The enclosure of the interface will be weather-proof along with any cable jacks used.
- An option to integrate thermocouples with the system will be available.


# Solution Components

## Switching Subsystem

- Contains switching components responsible for connecting different sections of the solar panel (32 cells, 64 cells, or 128 cells) to the output or disconnecting the solar panel altogether.
- The switching configuration will be controlled by the Processing Subsystem.

## Electrical Monitoring Subsystem

- Connects directly to the output of the switching subsystem and is responsible for measuring current and voltage.
- The subsystem has two outputs: one that communicates voltage/current data to the Processing Subsystem and another that passes power generated by the solar panel to the output of the interface box (and into power inverter).

## Temperature Monitoring Subsystem

- Contains all of the circuitry necessary to extract temperature data sourced from thermocouples that will be mounted on various areas of the solar panel.
- This data will be sent to the Processing Subsystem for further analysis.

## Manual Switches

- In case of a loss of connection to the internet and the server is unable to access the interface box, there will be manual switches mounted on the enclosure to control the configuration of the solar panel.
- These switches will not affect the configuration of the solar panel if the Ethernet Interface is in already in use.

## Processing Subsystem

- An internal microcontroller (most likely an ATmega328P) will be used to communicate with and control other subsystems present in the interface box.
- Detects overcurrent/overvoltage conditions using data sent by the Electrical Monitoring Subsystem.
- Detects hotspots and overheating using data sent by the Temperature Monitoring Subsystem.
- Controls the Switching Subsystem to set the output configuration the solar panel or disconnect it altogether if a failure condition is met.
- Packages and sends relevant data and receives configuration commands from the user through the Ethernet Interface.
- Reads the switch states from the Manual Switches to control the configuration of the solar panel if an Ethernet connection has not been established.

## Ethernet Interface

- Facilitates communication via Ethernet between a server/PC and the microcontroller installed in the interface box.
- Allows the command, control, and monitoring of the solar panel to take place.

## LED Display

- Several LEDs will be present to show information about:
-- Whether or not the interface box is active
-- The current configuration of the solar panel, or
-- Whether or not an Ethernet connection is active.

## Power Subsystem

- Regulates the 12V supply into voltage levels suitable to power all of the above subsystems.

## Software

- Receives data output through the Ethernet Interface and stores the information in a database of some sort.
- A python based GUI will be able to extract, transmit commands, and display the data, providing a user-friendly experience.
- Must be Windows compatible.
- Both the database and the GUI should be secured to prevent unauthorized users from controlling the solar panels.


# Criterion for Success

Our solution will be successful if it can accurately monitor a solar panel’s power output and temperature while simultaneously reporting this data to an external server. A GUI type interface should display output data from the interface box and allow the user to configure the solar panel remotely. In the case of a loss of connection to the internet, the interface box will be controlled by built-in buttons on the box. Additionally, the interface box will be a success if it can realize all of the items listed in the Key Features section above.

We aim to build a weather-proof device that can use an Ethernet LAN connection to then access a server where a user can check how the solar panels are doing at any given time. The end goal is to provide a fully functional prototype for the ECE department to use on one solar panel. With time and some refinement to the design, multiple interface boxes will be manufactured and installed on each of the ECEB research panels.


# Team Members

- Dillon Vadgama (dvadga2)
- Douglas Lee (dlee242)
- Sachin Reddy (ssreddy2)

Covert Communication Device

Ahmad Abuisneineh, Srivardhan Sajja, Braeden Smith

Covert Communication Device

Featured Project

**Partners (seeking one additional partner)**: Braeden Smith (braeden2), Srivardhan Sajja (sajja3)

**Problem**: We imagine this product would have a primary use in military/law enforcement application -- especially in dangerous, high risk missions. During a house raid or other sensitive mission, maintaining a quiet profile and also having good situational awareness is essential. That mean's that normal two way radios can't work. And alternatives, like in-ear radios act as outside->in communication only and also reduce the ability to hear your surroundings.

**Solution**: We would provide a series of small pocketable devices with long battery that would use LoRa radios to provide a range of 1-5 miles. They would be rechargeable and have a single recessed soft-touch button that would allow someone to find it inside of pockets and tap it easily. The taps would be sent in real-time to all other devices, where they would be translated into silent but noticeable vibrations. (Every device can obviously TX/RX).

Essentially a team could use a set of predetermined signals or even morse code, to quickly and without loss of situational awareness communicate movements/instructions to others who are not within line-of-sight.

The following we would not consider part of the basic requirements for success, but additional goals if we are ahead of schedule:

We could also imagine a base-station which would allow someone using a computer to type simple text that would be sent out as morse code or other predetermined patterns. Additionally this base station would be able to record and monitor the traffic over the LoRa channels (including sender).

**Solutions Components**:

- **Charging and power systems**: the device would have a single USB-C/Microusb port that would connect to charging circuitry for the small Lithium-ion battery (150-500mAh). This USB port would also connect to the MCU. The subsystem would also be responsible to dropping the lion (3.7-4.2V to a stable 3.3V logic level). and providing power to the vibration motor.

- **RF Communications**: we would rely on externally produced RF transceivers that we would integrate into our PCB -- DLP-RFS1280, https://www.sparkfun.com/products/16871, https://www.adafruit.com/product/3073, .

-**Vibration**: We would have to research and source durable quiet, vibration motors that might even be adjustable in intensity

- **MCU**: We are likely to use the STM32 series of MCU's. We need it to communicate with the transceiver (probably SPI) and also control the vibration motor (by driving some transistor). The packets that we send would need to be encrypted (probably with AES). We would also need it to communicate to a host computer for programming via the same port.

- **Structural**: For this prototype, we'd imagine that a simple 3d printed case would be appropriate. We'd have to design something small and relatively ergonomic. We would have a single recessed location for the soft-touch button, that'd be easy to find by feel.

**Basic criterion for success:** We have at least two wireless devices that can reliably and quickly transfer button-presses to vibrations on the other device. It should operate at at *least* 1km LOS. It should be programmable + chargeable via USB. It should also be relatively compact in size and quiet to use.

**Additional Success Criterion:** we would have a separate, 3rd device that can stay permanently connected to a computer. It would provide some software that would be able to send and receive from the LoRa radio, especially ASCII -> morse code.