Lost Item Pager System Design Russ Kinley 5/6/6008

MCU Choice Base: Base: MC13213 MC MHz 16 MHz Micro C/OS Micro C/OS 8KB ROM (flash) 8KB ROM (flash) 2KB RAM 2KB RAM Pagers: Pagers: MC13211 MC MHz 16 MHz Time-slice Kernel Time-slice Kernel 2KB ROM (flash) 2KB ROM (flash) 100 Bytes RAM 100 Bytes RAM

Tasks (Base) 4. Start Task 5. Button Press Task 6. Send Receive Task 7. Display Task 8. Count Task

Start Task Initializes system Initializes system Creates other tasks Creates other tasks Priority: 4 Priority: 4 Period: run-once Period: run-once Execution Time: 1sec Execution Time: 1sec

Button Press Task Detects a valid button press Detects a valid button press Priority: 5 Priority: 5 Period: 10ms Period: 10ms Execution time: 20usec Execution time: 20usec

Send Receive Task Sends start/stop page messages Sends start/stop page messages Reads return messages from Pagers Reads return messages from Pagers Priority:6 Priority:6 Period: 1sec Period: 1sec Execution time: 10msec Execution time: 10msec

Display Task Determines which message is displayed Determines which message is displayed Displays all messages on LCD Displays all messages on LCD Priority: 7 Priority: 7 Period: 1sec Period: 1sec Execution time: 10msec Execution time: 10msec

Count Task Used as a timer for Display Task’s display Used as a timer for Display Task’s display Priority: 8 Priority: 8 Period: 1sec Period: 1sec Execution time: 10usec Execution time: 10usec

CPU Load (Base) TaskExecution (ms)Period (ms)Load Start100 Button Send/Receive Display Count Max: Average: 0.012

Base Modules Main: Start Task, Display Task, Count Task Main: Start Task, Display Task, Count Task LCD: (no tasks) LCD: (no tasks) Button: Button Press Task Button: Button Press Task Wireless: Send Receive Task Wireless: Send Receive Task

Data Flow Diagram (Base)

Pager Tasks Start Task Start Task Wake-up Task Wake-up Task Send Receive Task Send Receive Task Button Press Task Button Press Task Beep Task Beep Task

Start Task Initializes device upon reset Initializes device upon reset Period: run once Period: run once Execution time: 1 sec Execution time: 1 sec

Wake-Up Task Uses an RTI to awaken the pager from sleep mode. Uses an RTI to awaken the pager from sleep mode. Period: 20msec(timeslice period) Period: 20msec(timeslice period) Execution time: 10usec Execution time: 10usec Holds pager awake for 1sec and in sleep for 14sec to help not to miss a signal and wait longer for a response and conserve battery. Holds pager awake for 1sec and in sleep for 14sec to help not to miss a signal and wait longer for a response and conserve battery.

Button Press Task Detects a valid button press Detects a valid button press Signals others tasks to end function Signals others tasks to end function Period: 20msec (when active) Period: 20msec (when active) Execution time: 10usec Execution time: 10usec

Beep Task Turns on/off LEDs and speaker with a 50% duty cycle overall. Turns on/off LEDs and speaker with a 50% duty cycle overall. Period: 100usec Period: 100usec Execution time: 10usec Execution time: 10usec

Send Receive Task Receives signals from Base, determines if signal is intended from that device. Receives signals from Base, determines if signal is intended from that device. Returns acknowledge signals to Base Returns acknowledge signals to Base Period: 500msec (25 time-slice periods) Period: 500msec (25 time-slice periods) Execution time: 1msec (send), 15msec (receive) Execution time: 1msec (send), 15msec (receive)

CPU Load TaskExecution (ms)Period (ms)Load Start Button Send Receive Beep Wakeup E-06 Max: average:

Data Flow Diagram