Audible Memo Board Phase II (08009)

The Project

Customer: IreneSponsor: Tala HopkinsConsultant: Dr. Hopkins

Advisor: Dr. Slack

The project required the design of a calendar that would be usable by the blind and those with a poor sense of touch. Our solution is a calendar that lets her easily record and playback voice messages.

Record

Playback

Erase

Memo Page

Power

Month Cycle

Message Cycle

Audio Clock

Speaker Volume

Calendar

TEAM MEMBERSJim Varghese – Electrical Engineer , Schematic, PowerLoic Hureau – Electrical Engineer, Audio In/Out, Board PopulationJon Gosliga* – Electrical Engineer, Audio In/Out, CablingAlex Gorevski – Computer Engineer, A/D-D/A, Software

* - Team Leader

USER INTERFACE

Project ObjectiveTo re-evaluate the original audible memo board design, improve upon, and add unimplemented functionality. The audible memo board enables a blind person with neuropathy in the fingertips to keep track of appointments through a voice recording and playbacks using a memory subsystem. This device serves the same purpose a paper calendar would for a person with sufficient sight.

ElectronicsThis record and playback device centers on an Atmel microcontroller with multiple subsystems, including analog-digital conversion and a NAND Flash memory subsystem. The Electronics design includes three distinct subsystems. The audio-input subsystem includes a noise-cancelling microphone, audio preamplifier and filter design. The audio-output subsystem includes a digital-analog conversion chip, a series of amplifiers, and filters to cancel out and soften background noises and extremely high and low frequencies when dealing with voice communication, including a speaker built into the device as well as a speaker that may be plugged in externally for louder output. The microprocessor subsystem handled all of the memory storage and playback in a NAND Flash memory bank, the background logic which drives the device, and reading the current time and date from the internal clock chip. The user-interface buttons were constantly polled to simulate interrupt-driven user control. The power supply design featured a wall-mounted twelve-volt supply feeding 12V to voltage conversion circuitry to provide 4 DC voltage levels needed by the electronics.

Features The audible memo device is an audible electronic calendar, which enables the user to record appointments and memos, and play them back when needed. The user interface includes 42 buttons, each pertaining to a day of the week, and Velcro strip on the middle column to denote Wednesday. Large colorful buttons will help the customer differentiate the buttons. The device also makes it possible to play back and skip to the desired message that was recorded. The audible memo allows the user to record and playback multiple appointments on one day. To help the user navigate the keyboard, the device includes audio prompts and confirmation for button presses. Appointments can easily be retrieved by pressing a calendar button which will automatically play all the messages that have been recorded on that day. In addition to the calendar, the board offers a memo page. This page is intended for recording things like phone numbers and it is accessed by pressing the memo page button. To announce the current day and time a clock button has been included.

The Team

Electronics Circuit Board

Subsystem Design

& Logic LayoutCircuitry

Start Initialize

Get Key

Which Mode?Memo Mode

Logic

Hidden Mode Logic

Calendar Mode Logic

When each mode of logic has completed, Get Key

polls the buttons for another press

*Sets up all input and output pins*Initializes the ADC

*Sets the clock speed*Reads the current date on the clock chip

The main() function determines which button was pressed and a different form of logic is selected based on

this button press

The system is powered on.

Set the Global Variable for the current mode

Memory Hierarchy

Locations [0 95]Instructional Memory & Reserved Storage

Locations [96 828]Calendar Pointer Locations for up to Two Years

Locations [829 812]Temporary Memory Storage

Locations [813 2047]Free Memory Storage Area

4 Blocks = 60 Seconds of Record Time

Memos and Messages can be recorded and played back for up to 60 seconds.

Instructional messages are re-recordable and can have up to a duration of 15 seconds.