Project :: ECE 445 - Senior Design Laboratory

#	Title	Team Members	TA	Documents	Sponsor
41	Door Access Tracker	Benjamin Wasicki John Scholl Patrick Connelly	Chi Zhang	design_document1.pdf design_document2.pdf design_document3.pdf design_document4.pdf design_document5.pdf final_paper1.pdf presentation1.pdf proposal1.pdf proposal2.pdf
	##### Patrick Connelly (prc2), Benjamin Wasicki (wasicki2), John Scholl (johnts2) # Door Access Tracker ### Problem: Many areas of day-to-day life involve the opening and closing of a door. We believe that better information on the state of a door can improve quality of life. For example, one could monitor a door as a security measure, such as a front door, a liquor closet, or a medicine cabinet. In addition, knowing when the mailbox has been accessed could be time saving, especially for someone who has mobility problems. Therefore, we would like to create a device to solve this problem that is cheap, versatile, and easy to install. ### Solution We propose the Door Access Tracker to solve this specific problem. This would consist of a four part system: - Door Status Sensor - This is a two-piece system for tracking the state of the door. Our current idea is to mount one magnet on the door itself, and another on the frame of the door, allowing for the magnets to act on each other only when the door is closed. Close proximity of the magnets would pull on a conductive component, opening a circuit and changing the current output signal. - System Controller - This is the main computing device, consisting of a battery, a micro-controller, and a WiFi card. These would require very lower power and bandwidth. The primary function of this component is receiving a signal from the sensor and transferring this signal to the WiFi card, which provides this data to a remote server. - Backend Server - This would be the server that would receive updates from each system controller and send out updates to each app associated with the specific system controller based on the configurations set in the app. We plan to run a basic container with our server on some cloud computing platform, possibly Google Cloud. As our server requires very little computing power, costs associated with running it would be negligible. - Android Application - This would be the app that would connect to the backend server. It would tell the backend server to associate it with specific system controllers and receive updates based on configurations it sends to the backend server. ### Criterion for Success To be effective, our device must meet the following criteria: - Accurately determine the state of a door - Reliably send the state of the door to the server upon a state change - Server sends notifications of door state to the app based on set configurations - App alerts user based on notification received from server

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.

Project Videos

Musical Hand Demo