Individual Progress Report

Description

The Individual Progress Report (IPR) is a chance to put your contributions to the team's progress in writing. The report will discuss not only the components and subsystems you have personally been responsible for, but what components you have helped work on as well. It is important to talk about the relation between your work and your teammates' work as well.

Requirements and Grading

This report should be 5-12 pages of your own work. This means that you cannot take paragraphs/text from your Design Review document, since that was a collaborative effort. The IPR Grading Rubric describes what we look for in grading this assignment. The requirements are expanded on below:

  1. General: Concise writing is encouraged, but it is important that all pertinent information is conveyed. All figures should be labeled and formatted consistently.
  2. Formatting: Please refer to the Final Report Guidelines for general writing guidelines, since the format of this report should be very similar to that of the final report. Note that each component of the Final Report may be tailored to the parts of the project the individual has been active in.
  3. Introduction: First, discuss what portion of the system you have been active in designing connects to which portion of a different subsystem, and how these interact to complete an overall objective. Then discuss what you have accomplished, what you are currently working on, and what you still have left to do.
  4. Design: Discuss the design work you have done so far. It is expected that you have done calculations and/or found relevant equations, created circuits for your parts of the project, and simulated / drawn schematics for your parts. You may have already, at a high level, discussed how your part fits into the rest of the project, but you should expand on the technical details and interface between your module(s) and the other modules of the project.
  5. Verification: Testing and verification is also very important. Make sure you describe each test that was performed and its procedure in detail, and give quantitative, meaningful results. Also describe tests that have yet to be performed. We should be convinced that if all your tests will pass, your part of the project will work.
  6. Conclusion: Discuss a plan and timeline for completing your responsibilities and your project as a whole. Also explain the ethical considerations of your project by consulting the IEEE Code of Ethics, ACM Code of Ethics, or another relevant Code of Ethics.
  7. Citations: You need citations. Cite sources for equations, Application Notes you referenced in your design, and any literature you used to help design or verify your work. If you checked something from another course's lecture slides, Google'd for things related to your project, or anything similar, then you have something you need to cite. At the very least, since you have talked about the ethical considerations of your project as it relates to a published code of ethics (e.g., IEEE or ACM), you should cite those!

Submission and Deadlines

The IPR should be submitted on canvas in PDF format by the deadline listed on the Course Calendar.

CHARM: CHeap Accessible Resilient Mesh for Remote Locations and Disaster Relief

Martin Michalski, Melissa Pai, Trevor Wong

Featured Project

# CHARM: CHeap Accessible Resilient Mesh for Remote Locations and Disaster Relief

Team Members:

- Martin Michalski (martinm6)

- Trevor Wong (txwong2)

- Melissa Pai (mepai2)

# Problem

There are many situations in which it is difficult to access communicative networks. In disaster areas, internet connectivity is critical for communication and organization of rescue efforts. In remote areas, a single internet connection point often does not cover an area large enough to be of practical use for institutions such as schools and large businesses.

# Solution

To solve these problems, we would like to create a set of meshing, cheap, lightweight, and self-contained wireless access points, deployable via drone. After being placed by drone or administrator, these access points form a WiFi network, usable by rescuers, survivors, and civilians. Our network will have QoS features to prioritize network traffic originating from rescuers. Having nodes/access points deployable by drone ensures we are able to establish timely connectivity in areas where search and rescue operations are still unable to reach.

Over the course of the semester, we will produce a couple of prototypes of these network nodes, with built in power management and environmental sensing. We aim to demonstrate our limited network’s mesh capabilities by setting up a mock network on one of the campus quads, and connecting at various locations.

# Solution Components

## Router and Wireless Access Point

Wireless Access for users and traffic routing will be the responsibility of an Omega2 board, with onboard Mediatek MT7688 CPU. For increased signal strength, the board will connect to a RP-SMA antenna via U.FL connector.

The Omega2 will be running OpenWRT, an Linux-based OS for routing devices. We will develop processes for the Omega2 to support our desired QoS features.

## Battery Management System

This module is responsible for charging the lithium-ion battery and ensuring battery health. Specifically, we will ensure the battery management system has the following features:

- Short circuit and overcurrent protection

- Over- and under-voltage protection

- An ADC to provide battery status data to the microcontroller

- 3.3v voltage regulation for the microcontroller and other sensors

In addition to miscellaneous capacitors and resistors, we intend to use the following components to implement the battery management system:

- The MT2492 step-down converter will be used to step down the output voltage of the battery to 3.3 volts. Between the GPS and extra power the microcontroller might consume with an upgraded Wifi antenna, low-dropout regulators would not provide sufficient power in an efficient manner. Instead, we will implement a 2 amp buck converter to improve efficiency and ensure there are no current bottlenecks.

- We will utilize two button-top protected 18650 3400 mAh lithium ion batteries in series to power each node. Placing two of these batteries in series will ensure their combined voltage never falls below the minimum voltage input of the buck converter, and accounting for the buck converter’s inefficiency these batteries should give us about 21 Wh of capacity. The cells we plan on using include a Ricoh R5478N101CD protection IC that provides over-voltage, under-voltage, and over-current protection. Using a standard battery form factor will make them easy to replace in the future as needed.

- A USB-C port with two pulldown resistors will provide 5 volt charging input with up to 3 amps of current, depending on the charger.

- The MT3608 step-up converter will boost the input voltage from the usb-c port and feed it into the charging controller.

- The MCP73844 Charge Management Controller will be used to charge the batteries. This controller supports CC/CV charging and a configurable current limit for safe and effective battery charging.

- The TI ADS1115 ADC will be used for battery voltage monitoring. This chip is used in the official Omega2 expansion board, so it should be easy to integrate in software. We will use a voltage divider to reduce the battery voltage to a range this chip can measure, and this chip will communicate over an I2C bus.

## Sensor Suite

Each node will have a battery voltage sensor and GPS sensor, providing the system with health information for each node. On top of the Wifi-connectivity, each module would have a series of sensors to detect the status of the physical node and helpful environment variables. This sensor suit will have the following features and components to implement it

- Ultimate GPS Module PA1616D will be used for positioning information. This chip utilizes 3.3V which is supplied through our battery management system.

Battery Voltage Monitor

- The TI ADS1115 ADC (mentioned in the BMS section) is for battery voltage monitoring. It interfaces via I2C to the Omega2.

## System Monitor

A system monitor which provides visibility of the overall system status for deployed network nodes. Information that we will show includes: last known location, battery health, and network statistics (e.g. packets per second) from the physical devices.

We plan on using React to provide an intuitive UI, using google-map-react and other React packages to create an interactive map showing the last known location and status of each node.

The backend will be hosted on a server in the cloud. Nodes will continually update the server with their status via POST requests.

# Criterion For Success

We aim to achieve the following performance metrics:

- 1.5 kg maximum mass

- Cover 7500 m^2 (North Quad) with 4 nodes

- Display the last known location, time connected, and battery voltage for all nodes via our system monitor

- 3 hour battery life

- 5 Mb/s WiFi available to laptops and smartphones in the coverage area

[*Link*](https://courses.engr.illinois.edu/ece445/pace/view-topic.asp?id=71252) *to assciated WebBoard discussion*