# Title Team Members TA Documents Sponsor
42 Vehicle Detection Cane
Aditi Panwar
Neva Manalil
Nicholas Halteman
Johan Mufuta design_document6.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.

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.

## 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.

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.

Master Bus Processor

Clay Kaiser, Philip Macias, Richard Mannion

Master Bus Processor

Featured Project

General Description

We will design a Master Bus Processor (MBP) for music production in home studios. The MBP will use a hybrid analog/digital approach to provide both the desirable non-linearities of analog processing and the flexibility of digital control. Our design will be less costly than other audio bus processors so that it is more accessible to our target market of home studio owners. The MBP will be unique in its low cost as well as in its incorporation of a digital hardware control system. This allows for more flexibility and more intuitive controls when compared to other products on the market.

Design Proposal

Our design would contain a core functionality with scalability in added functionality. It would be designed to fit in a 2U rack mount enclosure with distinct boards for digital and analog circuits to allow for easier unit testings and account for digital/analog interference.

The audio processing signal chain would be composed of analog processing 'blocks’--like steps in the signal chain.

The basic analog blocks we would integrate are:

Compressor/limiter modes

EQ with shelf/bell modes

Saturation with symmetrical/asymmetrical modes

Each block’s multiple modes would be controlled by a digital circuit to allow for intuitive mode selection.

The digital circuit will be responsible for:

Mode selection

Analog block sequence

DSP feedback and monitoring of each analog block (REACH GOAL)

The digital circuit will entail a series of buttons to allow the user to easily select which analog block to control and another button to allow the user to scroll between different modes and presets. Another button will allow the user to control sequence of the analog blocks. An LCD display will be used to give the user feedback of the current state of the system when scrolling and selecting particular modes.

Reach Goals

added DSP functionality such as monitoring of the analog functions

Replace Arduino boards for DSP with custom digital control boards using ATmega328 microcontrollers (same as arduino board)

Rack mounted enclosure/marketable design

System Verification

We will qualify the success of the project by how closely its processing performance matches the design intent. Since audio 'quality’ can be highly subjective, we will rely on objective metrics such as Gain Reduction (GR [dB]), Total Harmonic Distortion (THD [%]), and Noise [V] to qualify the analog processing blocks. The digital controls will be qualified by their ability to actuate the correct analog blocks consistently without causing disruptions to the signal chain or interference. Additionally, the hardware user interface will be qualified by ease of use and intuitiveness.

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