Embedded System Design

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• Embedded System Design
• Spring 2004
• Harold Allen, Hal Hollis, Eric Maxwell

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Project Overview

• Objective Create an embedded PC hardware and
  software remote alarm monitoring solution.
• Concept A PC in an unmanned facility monitors
  assorted sensors for alarm conditions (e.g.,
  intrusion, over/under temp, equipment failure
  etc.). Upon detection of alarm, the PC dials a
  phone number, plays a pre-recorded alarm message
  and waits for a response via a telephone key
  press.
• Hardware A custom full size ISA PCB with analog
  telephony interface, DTMF transceiver, ADC, and
  DAC. Sensor hardware interface simulated in
  software for this project.
• Software Three elements - Device Driver, Alarm
  Service, GUI

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Block Diagram
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PCV100 (Telephony Card)
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Device Driver

• Layered MDD/PDD approach
• PDD based on SoundBlaster example
• Coding concentrated in three functions
  PDD_AudioInitialize PDD_AudioGetInterruptType
  PDD_AudioMessage
• IRQ DMA coding straightforward
• Custom hardware control messages

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Alarm Service

• Persistent thread catches alarm events
• Dials from telephone list created by GUI
• Plays correlating alarm message and waits for
  DTMF confirmation
• Using PCV100 hardware functions and standard
  waveOut routines
• Logs all alarm activities for future reference

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Graphical User Interface

• GUI designed with Visual Basic
• Backend code contained in a C DLL
• User interaction is handled by the VB GUI
• Service interaction is handled by the DLL
• GUI also controls the configuration file
• Some problems in designing the GUI

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Graphical User Interface
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Milestones
Milestone Planned Actual Functioning
Hardware NA 03/15 Device Driver
Working 04/09 04/04 Service Working 04/09 0
4/08 GUI Working 04/09 04/21 Verification 04/
16 04/21 Integration 04/23 04/22 Demo 04/
23 04/23 Documentation 04/26 04/26
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Conclusion

• Developed a device driver that utilizes
  interrupts and DMA
• Developed an event driven service task that
  communicates with the device driver
• Developed a GUI to manage the service task
  configuration file and install, start and stop
  the alarm service process
• Created a Windows CE kernel bootable from CD