SPEAKER CONTROL SYSTEMEMBEDDED SYSTEMS FINAL PROJECT

WADE HANSEN & SORA SOGUR

System Diagram

TouchOSC iPhone App• Sends Open Sound Control (OSC)

messages via 802.11 to PC application

• Configurable layout where input components correspond to individual OSC messages

• Can send and receive messages from host inside or outside of internal Wi-Fi network- opens up many possibilities for future projects using this app

Processing PC Application

• Open source language and IDE built for electronic arts and visual design

• Similar to Java language• Uses built-in OSC library to

receive OSC messages• Uses Processing Serial library

functions to send data out to XBee development board

• Application can also send the speaker selector commands (by clicking toggle buttons)

XBee RF Modems• Easy to configure,

low power TxRx modules• Transmits up to 300 feet indoors• Cheap! ~ $20• Uses 802.15.4

(ZigBee wireless protocol)• In addition:

10 Digital I/O pins for sampling analog/digital signals

• PC side XBee receives serial control signals via RS-232 connection and transmits to µC-side XBee.

Microcontroller/TxRx Board• Uses the

Olimex 28-pin development board with Atmega88PA

• Four output pins control relays

• Two USART I/O pins connect to Xbee’s UART Data In/Out

Speaker Selector Module

• Passive device used to switch on/off 4 separate pairs• Includes “Impedance Protection”• Four mechanical push-button switches removed,

replaced by four DPDT relays. • Relay latching triggered by 4 microcontroller outputs• Indicator LEDs added to panel

Modified Speaker Selector Module

LEDs addedto front panel

4 DPDTrelays Impedance

Protectionresistors

Speaker Switch Schematic

Other Potential Uses

• Home Automation• Security• Lighting• Power Management

• Remote Control Tank• Electronic Instrument

Controllers• Keyboards• Drum Machines• Sequencers

• “Doggy Door Latch”

Photo Courtesy of Geeky-Gadgets.com

DEMONSTRATION