Project :: ECE 445 - Senior Design Laboratory

#	Title	Team Members	TA	Documents	Sponsor
27	Global Active Noise Cancellation for Cell Phone Privacy	Hershed Tilak Joel Godard		design_document0.document final_paper0.pdf presentation0.pdf proposal0.pdf
	The motivation for this project is to provide privacy for those making cell phone calls in public spaces. Achieving audio isolation would pose great benefits to both the cell phone user as well as those surrounding him/her. We will be investigating the feasibility of using active noise cancellation to suppress the voice of a cell phone user globally. This method of isolation employs destructive interference and hinges on the collocation of both the initial sound source and the source of noise cancellation in order to achieve the desired global noise control. Furthermore, the destructively interfering signal must maintain equal amplitude with the initial signal over all space in order to provide complete cancellation. The investigation will be performed at first on a dummy object that is roughly the size of a standard cell phone. Microphones along with supporting circuitry will be located on the dummy cell phone in order to obtain the initial signal (speaker's voice). The signal will then be passed to a digital signal processor which will change its phase by 180 degrees. Finally, speakers on the back of the dummy cell phone will be used to emit this inverted signal in order to actively cancel the person's voice in the far field. A characterization of the pattern of spatial intensity of the human voice will be performed, and different speaker placements will be studied in hope of providing the best cancellation over a large area surrounding the person using the phone.

Featured Project

# People

Scott Liu - sliu125

Connor Lake - crlake2

Aashish Kapur - askapur2

# Problem

Buses are scheduled inefficiently. Traditionally buses are scheduled in 10-30 minute intervals with no regard the the actual load of people at any given stop at a given time. This results in some buses being packed, and others empty.

# Solution Overview

Introducing the _BusPlan_: A network of smart detectors that actively survey the amount of people waiting at a bus stop to determine the ideal amount of buses at any given time and location.

To technically achieve this, the device will use a wifi chip to listen for probe requests from nearby wifi-devices (we assume to be closely correlated with the number of people). It will use a radio chip to mesh network with other nearby devices at other bus stops. For power the device will use a solar cell and Li-Ion battery.

With the existing mesh network, we also are considering hosting wifi at each deployed location. This might include media, advertisements, localized wifi (restricted to bus stops), weather forecasts, and much more.

# Solution Components

## Wifi Chip

- esp8266 to wake periodically and listen for wifi probe requests.

## Radio chip

- NRF24L01 chip to connect to nearby devices and send/receive data.

## Microcontroller

- Microcontroller (Atmel atmega328) to control the RF chip and the wifi chip. It also manages the caching and sending of data. After further research we may not need this microcontroller. We will attempt to use just the ens86606 chip and if we cannot successfully use the SPI interface, we will use the atmega as a middleman.

## Power Subsystem

- Solar panel that will convert solar power to electrical power

- Power regulator chip in charge of taking the power from the solar panel and charging a small battery with it

- Small Li-Ion battery to act as a buffer for shady moments and rainy days

## Software and Server

- Backend api to receive and store data in mongodb or mysql database

- Data visualization frontend

- Machine learning predictions (using LSTM model)

# Criteria for Success

- Successfully collect an accurate measurement of number of people at bus stops

- Use data to determine optimized bus deployment schedules.

- Use data to provide useful visualizations.

# Ethics and Safety

It is important to take into consideration the privacy aspect of users when collecting unique device tokens. We will make sure to follow the existing ethics guidelines established by IEEE and ACM.

There are several potential issues that might arise under very specific conditions: High temperature and harsh environment factors may make the Li-Ion batteries explode. Rainy or moist environments may lead to short-circuiting of the device.

We plan to address all these issues upon our project proposal.

# Competitors

https://www.accuware.com/products/locate-wifi-devices/

Accuware currently has a device that helps locate wifi devices. However our devices will be tailored for bus stops and the data will be formatted in a the most productive ways from the perspective of bus companies.