Project

# Title Team Members TA Documents Sponsor
26 Secure Mailbox with Mobile Connectivity
 Avadh Patel
Neehar Sawant
Roshun Navin
 Vishal Dayalan design_document2.pdf
final_paper1.pdf
photo1.png
photo2.png
presentation1.pdf
proposal1.pdf
video
Secure Mailbox with Mobile Connectivity

Team Members:
Neehar Sawant (neehar2),
Avadh Patel (apate429),
Roshun Navin (rnavin2)

Problem:
Mail is an integral part of how we receive information from other people, our communities, and businesses alike. However, even though it is delivered almost everyday, mail containing your personal information is in many cases not secure and risks being taken by others. While apartment buildings have keys which are only possessed by the tenant and mailman, many single family and townhomes have a conventional mailbox which is able to be opened by anyone. Currently, smart boxes exist for packages that can be placed outside your front door to be notified when you have a package, but this does not solve the issue for normal paper mail. Upon further inspection, there does not seem to be a smart mailbox which is both secure and can be mounted in place of an existing mailbox.

Solution Overview:
Our solution is to create a mailbox that is able to automatically lock as well as schedule when it is unlocked and send status updates to a mobile application.
The mailbox will use a magnetic contact sensor to determine when the mailbox is opened and then send a signal to the PCB that sets a ready state and waits for the close signal. Once the door is closed, the magnetic contact sensor will send another signal to the PCB which in turn instructs the lock to close.
The PCB will also interface with the mobile application which will send unlock and lock signals to the PCB to control the actions of the locking mechanism. This system will also be used for unlocking the mailbox during a scheduled window which can be controlled in the app.
In order to notify the user if mail is present in the mailbox, multiple ultrasonic sensors will be used to detect if mail is covering any one of them. This information will be sent back to the PCB and then be sent to the mobile application to alert the user of mail.



Solution Components:
- Micro Servo Motor: This small, low powered, motor will be used to lock and unlock the mailbox. It will be attached to a metal extension to secure the lock. Something such as: FeeTech S0005 analog servo.

- Ultrasonic Sensor: This will be used to determine with greater accuracy than a weight sensor whether mail is present inside of the mailbox by checking if the sensor is covered or not.
https://www.sparkfun.com/products/15569

- Magnetic Contact Sensor: This will be used to determine when the mailbox is being opened and closed. The magnetic sensor has two components and when they are separated a signal is delivered. It will be separated when the door is opened. Something such as: 7939WG Magnetic Contact https://buildings.honeywell.com/us/en/products/by-category/sensors/contact-sensors/7939wg-magnetic-contact

- Wireless module: This will be used to allow the microcontroller to communicate with our mobile application. Something such as: ESP8266.

- Mailbox: We will use a 3d printer to create the mailbox outer casing

- Battery: Lithium Ion Battery - https://www.sparkfun.com/products/13855

# Subsystem 1: Power
We will utilize a battery for power and take the necessary steps to supply the PCB, motor, sensors, and other components with the required voltage demands.

# Subsystem 2: Locking Mechanism
The locking mechanism will be utilizing a servo to lock and unlock the mailbox. When the servo is in a horizontal position it will be used as a barrier between the door and the chassis so that the door cannot be opened. It will be moved to a vertical position when the user wants the mailbox to be unlocked in order for the door to open. The locking mechanism will be connected to the PCB which will send the unlock and lock commands.

# Subsystem 3: Sensors Subsystem
There will be ultrasonic sensors in the base of the mailbox and it will detect whenever mail or a package is placed in the mailbox. They will be placed at several positions along the base to ensure mail is detected and the user is accurately notified. We will also have a magnetic contact sensor at the top of the door. This will allow us to accurately know when the door is closed so that we can accordingly lock and secure the mail. Furthermore, we will have a wireless module allowing WIFI connectivity and data transfer to and from the mobile app. All sensors will be connected to and controlled from the PCB.

# Subsystem 4: Application
There will be a mobile application that will be created in order for the user to manually unlock and lock the mailbox. The user will also be able to set time windows in which the mailbox will be unlocked in case of multiple deliveries.

Criterion for Success:
- The mailbox is able to automatically lock and secure the mail after closing

- The mailbox is able to detect mail present and send a notification to the user’s application

- The user is able to lock and unlock the mailbox remotely from the user’s application

- User is able to specify window of time where mailbox will be unlocked

Musical Hand

Ramsey Foote, Thomas MacDonald, Michelle Zhang

Musical Hand

Featured Project

# Musical Hand

Team Members:

- Ramesey Foote (rgfoote2)

- Michelle Zhang (mz32)

- Thomas MacDonald (tcm5)

# Problem

Musical instruments come in all shapes and sizes; however, transporting instruments often involves bulky and heavy cases. Not only can transporting instruments be a hassle, but the initial purchase and maintenance of an instrument can be very expensive. We would like to solve this problem by creating an instrument that is lightweight, compact, and low maintenance.

# Solution

Our project involves a wearable system on the chest and both hands. The left hand will be used to dictate the pitches of three “strings” using relative angles between the palm and fingers. For example, from a flat horizontal hand a small dip in one finger is associated with a low frequency. A greater dip corresponds to a higher frequency pitch. The right hand will modulate the generated sound by adding effects such as vibrato through lateral motion. Finally, the brains of the project will be the central unit, a wearable, chest-mounted subsystem responsible for the audio synthesis and output.

Our solution would provide an instrument that is lightweight and easy to transport. We will be utilizing accelerometers instead of flex sensors to limit wear and tear, which would solve the issue of expensive maintenance typical of more physical synthesis methods.

# Solution Components

The overall solution has three subsystems; a right hand, left hand, and a central unit.

## Subsystem 1 - Left Hand

The left hand subsystem will use four digital accelerometers total: three on the fingers and one on the back of the hand. These sensors will be used to determine the angle between the back of the hand and each of the three fingers (ring, middle, and index) being used for synthesis. Each angle will correspond to an analog signal for pitch with a low frequency corresponding to a completely straight finger and a high frequency corresponding to a completely bent finger. To filter out AC noise, bypass capacitors and possibly resistors will be used when sending the accelerometer signals to the central unit.

## Subsystem 2 - Right Hand

The right subsystem will use one accelerometer to determine the broad movement of the hand. This information will be used to determine how much of a vibrato there is in the output sound. This system will need the accelerometer, bypass capacitors (.1uF), and possibly some resistors if they are needed for the communication scheme used (SPI or I2C).

## Subsystem 3 - Central Unit

The central subsystem utilizes data from the gloves to determine and generate the correct audio. To do this, two microcontrollers from the STM32F3 series will be used. The left and right hand subunits will be connected to the central unit through cabling. One of the microcontrollers will receive information from the sensors on both gloves and use it to calculate the correct frequencies. The other microcontroller uses these frequencies to generate the actual audio. The use of two separate microcontrollers allows for the logic to take longer, accounting for slower human response time, while meeting needs for quicker audio updates. At the output, there will be a second order multiple feedback filter. This will get rid of any switching noise while also allowing us to set a gain. This will be done using an LM358 Op amp along with the necessary resistors and capacitors to generate the filter and gain. This output will then go to an audio jack that will go to a speaker. In addition, bypass capacitors, pull up resistors, pull down resistors, and the necessary programming circuits will be implemented on this board.

# Criterion For Success

The minimum viable product will consist of two wearable gloves and a central unit that will be connected together via cords. The user will be able to adjust three separate notes that will be played simultaneously using the left hand, and will be able to apply a sound effect using the right hand. The output audio should be able to be heard audibly from a speaker.

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