ECE 477 Design Review Team 22 Txt Msg DJ Garrett Strzelecki Kyle Brown John Dohert y Chris McCabe K
Feb 26, 2016
ECE 477 Design Review Team 22 Txt Msg DJ
Garrett Strzelecki
KyleBrown
John Doherty
Chris McCabe K
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. G
Project-Specific Success Criteria1. An ability to receive and parse text messages2. An ability to strobe and move lights in sync with
audio using the DMX512 protocol3. 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
excessivelyK
Component Selection RationaleRaspberry Pi• Inexpensive• Connects to Internet via Wi-fi• Can interface with existing web-based music
streaming servicesGSM Module• Inexpensive• Good documentation and service recordShift 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 AShift 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