ECE 477 Design Review Team 22 Txt Msg DJ

Garrett Strzelecki

KyleBrown

John Doherty

Chris McCabe

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Outline• Project overview • Project-specific success criteria• Block diagram• Component selection rationale• Packaging design• Schematic and theory of operation• PCB layout• Software design/development status• Project completion timeline• Questions / discussion

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Project Overview

The Text Message DJ is a standalone unit that creates and maintains a party playlist based on song requests sent from party guests via SMS. Guests can send text messages containing song names and the Text Message DJ will automatically parse messages, sort requests, and play the most popular by streaming from the internet. In addition to playing the song audio, the Text Message DJ will strobe lights in sync with the beat of the currently playing song. Settings are stored on a SD Card in plain text.

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Project-Specific Success Criteria

1. An ability to receive and parse text messages

2. An ability to strobe and move lights in sync with audio using the DMX512 protocol

3. An ability to queue songs based on the number of votes each song receives and display the queue on an LCD Screen

4. An ability to retrieve and play audio of requested songs using an online streaming service through an API

5. An ability to load configuration files from an SD card

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Block Diagram

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Component Selection Rationale

Microcontroller Design Constraints 3 UART/USART (RasPi, GSM, DMX 512) 2 SPI - 250kBaud (SD Card, LCD) 3 PWM (Strobe LED) 1 ATD (Audio Equalizer) 5 GPIO (Diagnostic LEDs) JTAG Programming and Debugging

ATxmega64A3U• Fits all design constraints without exceeding

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Component Selection RationaleRaspberry Pi• Inexpensive• Connects to Internet via Wi-fi• Can interface with existing web-based music

streaming services

GSM Module• Inexpensive• Good documentation and service record

Shift Register• Reduce connections external to PCB• Save GPIO pins for debugging

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Packaging Design

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Packaging Design• Rectangle shape:

– 6 x 9 x 2 inches• Peripherals:

– 2 x 16 LCD on front Panel– External Antenna– Power and wifi LED indicators– 6V power adapter in rear– SD Card slot– SIM Card– Audio out

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Schematic/Theory of Operation

Voltage Regulators:• 3 Different

Voltages Required• Varying Current

Requirements

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Schematic/Theory of Operation Microcontroller• Function: Parse SMS messages, control external

DMX device/s, control strobe LED, control LCD, manage song playlist, control raspberry pi

• Operating Mode:

3.3V• Headers on all pins

for debugging

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Schematic/Theory of Operation

Raspberry Pi• Function: Retrieve songs from internet,

output audio to external device• Operating Mode: 5V @ 700mA – 1.2A• Interface: UART: Port F

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Schematic/Theory of Operation

GSM Module• Function: Send and receive SMS messages• Operating Mode: 3.8V @ 400mA – 2A• Interface: UART: Port E

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Schematic/Theory of Operation

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Schematic/Theory of Operation

DMX Module/ RS 485 Level Converter• Function: Translate Microcontroller Signal to

DMX 512 Signal• Operating Mode: 3.3V @ 1mA• Interface: UART: Port E

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Schematic/Theory of OperationSD Card Reader• Function: SD card stores

setup files• Interface: SPI: Port D

Microcontroller bypass capacitors

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Schematic/Theory of OperationStrobe LEDs/Control Transistors• Function: Strobe to Music• Operating Mode: 5V @ 1A• Interface: PWM: Port A

Equalizer• Function: Convert

Audio to Strobe• Operating Mode: 3.3V• Interface: ADC &

General I/O: Port B

Schematic/Theory of OperationOther Components:

Reset Switch• Reset Pin

JTAG Header• Port B: JTAG

Diagnostic LEDs• General I/O: Port A

Shift Register and LCD Screen• Display Playlist• SPI & General I/O

– Port C

PCB Considerations

PCB Considerations

DMX SD Slot LCD Header Power Equalizer Debug LEDs Strobe LEDMicro GSM

MicroMicro

Reset

JTAG

Power Filter

Power Supply Considerations

5V 3.8V 3.3V

Software Design/Development Status

• Microcontroller– Event driven– Triggers: serial input (UART) from GSM

Module and Raspberry Pi• Raspberry Pi

– Event Driven– Trigger: serial input(UART) from Micro– Utilize ‘Twisted’ (Async Server Software)– Chrome CLI

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Project Completion Timeline

• 08-Mar: Final Schematic/PCB Layout• 11-Mar: N/A (Txt Msg DJ Company Holiday)• 20-Mar: Initial Software Design• 25-Mar: Raspberry Pi Interface with Micro &

GSM Module/SIM on PCB • 01-Apr: DMX Protocol/LCD Screen with

Queue on PCB• 08-Apr: Strobe LED/ SD Card functional

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Project Completion Timeline

• 15-Apr: PCB fully functional and assembled• 17-Apr: Project Packaged• 19-Apr: Completed User Manual• 22-Apr: Final Test and Setup for Demo• 24-Apr: Final Deliverables

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Questions / Discussion