FreeRTOS-Kernel/Demo/CORTEX_LM3S811_KEIL

/*

 * This project contains an application demonstrating the use of the 

 * FreeRTOS.org mini real time scheduler on the Luminary Micro LM3S811 Eval

 * board.  See http://www.FreeRTOS.org for more information.

 *

 * main() simply sets up the hardware, creates all the demo application tasks, 

 * then starts the scheduler.  http://www.freertos.org/a00102.html provides

 * more information on the standard demo tasks. 

 *

 * In addition to a subset of the standard demo application tasks, main.c also

 * defines the following tasks: 

 *

 * + A 'Print' task.  The print task is the only task permitted to access the

 * LCD - thus ensuring mutual exclusion and consistent access to the resource.

 * Other tasks do not access the LCD directly, but instead send the text they

 * wish to display to the print task.  The print task spends most of its time

 * blocked - only waking when a message is queued for display.

 *

 * + A 'Button handler' task.  The eval board contains a user push button that

 * is configured to generate interrupts.  The interrupt handler uses a 

 * semaphore to wake the button handler task - demonstrating how the priority 

 * mechanism can be used to defer interrupt processing to the task level.  The

 * button handler task sends a message both to the LCD (via the print task) and

 * the UART where it can be viewed using a dumb terminal (via the UART to USB

 * converter on the eval board).  NOTES:  The dumb terminal must be closed in 

 * order to reflash the microcontroller.  A very basic interrupt driven UART

 * driver is used that does not use the FIFO.  19200 baud is used.

 *

 * + A 'check' task.  The check task only executes every five seconds but has a

 * high priority so is guaranteed to get processor time.  Its function is to

 * check that all the other tasks are still operational and that no errors have

 * been detected at any time.  If no errors have every been detected 'PASS' is

 * written to the display (via the print task) - if an error has ever been

 * detected the message is changed to 'FAIL'.  The position of the message is

 * changed for each write.

 */