Project

# Title Team Members TA Documents Sponsor
42 Vehicle Detection Cane
Aditi Panwar
Neva Manalil
Nicholas Halteman
Johan Mufuta design_document6.pdf
design_document7.pdf
design_document8.pdf
design_document10.pdf
design_document1.pdf
design_document3.pdf
design_document4.pdf
design_document5.pdf
final_paper1.pdf
final_paper2.pdf
final_paper3.pdf
final_paper4.pdf
proposal2.pdf
proposal1.pdf
Neva Manalil (manalil2), Nick Halteman (nth2), Aditi Panwar (apanwa3)

# Problem

Blind people who use a cane rely on their hearing to determine if it is safe to cross a street. Gas fueled vehicles make a loud noise when driving by, but electric vehicles are virtually silent. With electric vehicles becoming more common it becomes more difficult for blind people to navigate as they cannot easily determine if it is safe to walk.

# Solution Overview

Our solution for determining if an area is safe to walk is a battery-powered cane attachment. When activated by pressing a button, it uses a radar sensor to determine if there are cars or other fast moving vehicles in front of the user and alerts the user with vibration if it is not safe to walk.

# Solution Components

## Sensor Subsystem

The sensor subsystem is responsible for using the doppler effect to identify moving vehicles. This technology has been in development in recent years for use in fully and partially autonomous cars. By emitting high frequency microwave “chirps” (above 77GHz) and “listening” for reflections off of objects, their general location and speed (the doppler effect) can be determined. Further processing can be performed to get more data on the object such as size and certain material characteristics (useful for differentiating between cars and other moving objects like people). We plan to use a radar transceiver such as the TEF810X (linked below), that has been designed for automotive use, and thus has no problem detecting cars at typical driving distances.

https://www.nxp.com/products/rf/radar-transceivers/tef810x-fully-integrated-77-ghz-radar-transceiver:TEF810X

An accompanying radar microcontroller is necessary to control and process data from the radar transceiver. It supports a hardware interface with the radar transceiver and hardware acceleration of common radar signal processing tasks. We intend to, as with the transceiver, use a radar microcontroller designed for automotive use such as the S32R Radar Microcontroller (linked below). This microcontroller is actually designed for use with the TEF810X.

https://www.nxp.com/products/processors-and-microcontrollers/power-architecture/s32r-radar-mcus/s32r-radar-microcontroller-s32r27-automotive-industrial-radar-applications:S32R27

## User Interface Subsystem

The radar microcontroller lacks the ability to interface with motors, speakers, and buttons, so a secondary microcontroller will be responsible handling them. The two microcontrollers can communicate through I2C or a similar interface. This allows us to be flexible with where some of the processing is done, as only the DSP intensive tasks have to be completed on the radar microcontroller. The following devices will be controlled by the secondary microcontroller:

Rocker Switch (with raised mark on one side) - turns the device on and off

Push Button - enables car scanning when held down

Vibration Motor - Relays information to the user through various patterns of vibration. This can include the presence of cars, mode of operation, etc.

Piezoelectric Speaker - To make a sound when the battery is about to die


## Power Subsystem

The system will run off two 18650 cells. A usb charger pcb (board used for making portable phone chargers, example linked below) will allow the cells to be charged with a usb cable . The board will also supply 5v at set currents. Voltage regulators will be used to correct the voltage for individual components (likely just one for 3.3v). A voltmeter will be used to determine the voltage across the battery and if the voltage becomes low, the piezoelectric speaker will alert the user.

https://www.banggood.com/Dual-USB-5V-1A-2_1A-Mobile-Power-Bank-18650-Battery-Charger-PCB-Module-Board-p-1031593.html?akmClientCountry=America&p=O516115442892201607W&cur_warehouse=CN

18650 Cells - provides power for the system

USB Charger PCB - handles recharging the batteries and provides 5v

Mini Voltmeter - To keep check on the charge in the battery (may be included in secondary microcontroller)

# Criterion for Success
The device reliably detects moving cars and alerts the user.

The device is easily operated by a blind person.

The device is comfortable and doesn’t infringe upon regular use of the cane.

The device is safe to rely on.

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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