USB to DMX Interface

1
USB to DMX Interface

• A Demonstration of
• The Game of Life
• Presented by
• Jeffrey Zampieron
• Brian G VanBuren

2
Introduction

• Project consists of three sections
• A Hardware Game of Life board
• USB to DMX Interface
• PC Software to control the board

3
Motivation for DMX

• Stage lighting often uses expensive, custom
  lighting consoles
• Laptops are inexpensive (relatively) and compact
• Easily movable when working on-stage
• PCs can run automated tasks to either run cues or
  do sequential dimmer tests

4
Motivation for USB

• USB is the defacto standard for connecting
  devices to a PC
• Supports Hot Plug and Play
• Speeds up to 480Mb/s
• Commonly available on Laptops

5
DMX512/1990

• DMX is a Stage Lighting control protocol
• USITT Standard established in 1990
• Hardware is RS485 compatible
• 250Kbps baud rate serial data stream
• Up to 512 devices, smaller amount allows greater
  refresh rate
• 11 Bits per frame

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USB to DMX Schematic
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USBMOD3 Schematic
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USBMOD3 Picture
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Game Board Schematic
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Game of Life

• Population simulation algorithm
• Shown on an LED matrix (8x8)
• Can be used to demonstrate automation
• Requires starting population
• Surrounding organisms determine
• Survival
• Death
• Birth

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PC Software

• User configurable starting matrix
• Able to save and load matrix states
• Allows matrices other than 8x8 to be used
• Up to eight 8x8 sections of the main matrix can
  be sent to the DMX boards

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Proposed User Interface
13
Proposed User Interface
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PIC16F747

• 40 Pin DIP
• UART (for the DMX RS485 bus)
• Parallel Port In (RA)
• Board Address for entire 8x8 Array (3 bit)
• PIC Address indicating row PIC control(3 bit)
  with row 0 at the bottom
• Parallel Port Out (RB)
• A bit per LED in the row it controls
• LSB is the rightmost LED

15
System Cost
Item Quantity Price/Unit Retail Price Our Cost
ICD2 PIC Programmer 1 159.00 159.00 0
ICD2 Interface Board 1 19.00 19.00 0
PIC16F747 12 6.85 82.20 82.20
USB Module 2 33.00 66.00 66.00
LEDs (Green) 100 0.297 29.70 29.70
Inverters (74LS04) 25 0.40 10.00 10.00
DMX Cable (5) 1 29.99 29.99 0
DMX Female Connector (5 pin XLR) 1 9.98 9.98 9.98
DMX Male Connector (5 pin XLR) 1 8.08 8.08 8.08
Resistors, IC Sockets, Switches, etc. 20.10 20.10
433.85 225.86
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Difficulties

• Game Board Construction
• Area Constraints
• 64 LEDS, 64 Resistors, 16 74LS04, 8 PICs
• More than 1000 solder joints!!!
• High Bit Rate DMX Issues
• Termination Issues
• PIC supporting 250Kbps

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Questions?