Speaker Control SYSTEM EMBEDDED 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 4 DPDT relays Impedance Protection resistors LEDs added to front panel

Speaker Switch Schematic

Other Potential Uses Home Automation Remote Control Tank Security Lighting Power Management Remote Control Tank Electronic Instrument Controllers Keyboards Drum Machines Sequencers “Doggy Door Latch” Photo Courtesy of Geeky-Gadgets.com

Demonstration