Ryan Hansgen

General System Design  MC9S08QE64CFT 24MHz Bus Frequency 64 K byte Flash EEPROM, 4.0 K byte RAM  Memory required 8 K bytes ROM 2 K bytes RAM  Kernal UCOS_II ○ Real-Time preemptive multitasking kernal ○ 1ms tick time

Task Priority  Start TaskPriority: 4  Button Task Priority: 5  GetTemperatureTaskPriority: 6  User Interface TaskPriority: 7

Modules  DigitalThermometer.c Startup Tasks Controls User Interface  MLX90614 Gets temperature from IR sensor  LCD  Button Reads when a button is pressed

Modules TasksPublic Functions and Data Digitalthermometer.cStartUpTask UserInterfaceTask Public Functions - Data - MLX90614 (Scott Corbridge) GetTemperatureTask Public Functions MLX90614SMBusIICInit() MLX90614GetTemps() MLX90614Configure() Data CurrentTemp Button.cButtonTask LCD.c (Todd Morton) Public Functions LcdInit(), LcdClrLine(), LcdDispChar(), LcdDispByte(), LcdDispStrg(), LcdMoveCursor(), LcdDispDecByte()

StartUp task  Creates other tasks  Period: Only runs once  Execution time: ~ 200ms

Button Task  Senses button presses  Period: 20 ms (sporadic)  Execution Time: ~ 400 μs

GetTemperatureTask  Gets Temperature data from IR sensor Converts to Fahrenheit  Period: 200ms  Execution time: ~ 100μs

UserInterfaceTask  State Machine Writes To LCD Activates LED’s  Period: 200ms  Execution time: ~ 5ms

CPU Load  L max = (400 us) + (100 us) + (5 ms) (20 ms) (200 ms) (200 ms)  L max =.0455  L average =.013

Data Flow